Glossary of botanical terms Last updated April 28, 2022 A In the bud leaves had their upper surfaces turned toward the stem and the Tetradenia riparia axil . The lower surface is ("away from the axis"), and the upper surface is abaxial adaxial.
Schematic diagrams of the
arrangement of the cotyledons and radicle in a seed of
Erysimum s Achene
on the surface of the stem of the infructescence of a strawberry
flower slit open and with one stamen bent upward to show its
attachment to the petal.
Diagram of a coconut fruit. The (endosperm) is labelled albumen Alb. Caffeine is an with four nitrogen atoms in its carbon skeleton. alkaloid
Rothmannia leaf with extensively
The apparently separate nuts of
s, two from each flower.
leaves of unidentified Arachnoid Gazania Blighia
, Akee seeds, one whole, one in longitudinal section, showing the pale
aril Infructescence of wild rye, showing prominent awn s Anatomy of an and bristles on a species of Australian grass awn ab- A prefix meaning "from, away from, or outside". abaxial The surface of an organ facing away from the organ's axis, e.g. the lower surface of a lateral organ such as a leaf or petal. Contrast . adaxial abort To abandon development of a structure or organ. abscission The shedding of an organ that is mature or aged, as of a ripe fruit or an old leaf. abscission zone A specialised layer of tissue that allows an organ to be shed by when it is ripe or senescent. Such tissue is commonly formed, for example, at the base of a abscission or petiole . pedicel acaulescent Having no apparent , or at least none visible above the ground surface. Examples include some species of stem , Agave , and Oxalis . Attalea  Antonym of (possessing stem) caulescent accrescent Increasing in size with age, such as a that continues to grow after the calyx has fallen, e.g. in corolla . Physalis peruviana accumbent Lying against another part of the plant; when applied to a , it means that one edge of the cotyledon lies along the cotyledon . radicle -aceae A suffix added to the stem of a generic name to form the name of a taxonomic family; for example, Rosaceae is the rose family, of which the type genus is . Rosa achene A dry, one-seeded indehiscent in which the true fruit is not the so-called "berry", but the achenes, which are the so-called "seeds" on the fruit , e.g. in the genus infructescence . Fragaria acicular Slender or needle-shaped. acropetal Moving from roots to leaves, e.g. of molecular signals in plants. acrophyll The regular of a mature plant, produced above the base, as opposed to leaves . bathyphyll acrostichoid (describing a type of ) Covering the entire sorus surface of a abaxial , usually densely so, as in frond and Elaphoglossum . Acrostichum actino- A prefix that indicates a radial pattern, form, or morphology. actinodromous ( leaf venation) or Palmate arranged venation with three or more radially s arising at or near the base of the leaf and reaching the primary vein in most species, but not all. margin actinomorphic or Regular symmetrical; may be bisected into similar halves in at least two planes. Applies e.g. to radially s and flowers in which the stele segments within each whorl are alike in size and shape. Compare perianth ; contrast regular , asymmetrical , and irregular . zygomorphic aculeate Armed with prickles, e.g. the stem of a rose. acuminate Tapering gradually to a point, with concave sides approaching the point. Contrast and acute . mucronate acute 1. Sharply pointed, but not drawn out, with straight sides approaching the point. Contrast . acuminate 2. Converging at an angle of less than 90°. Contrast . obtuse ad- A prefix meaning "near or toward"; also meaning "added to". adaxial The surface of an organ facing toward the organ's axis, e.g. the upper surface of a lateral organ such as a leaf or petal. Contrast . abaxial adelphia Plural: adelphiae. A bundle or structure of stamens forming one unit in an flower; for example, the stamen tube around the pistil of adelphous Hibiscus. adelphous Having organs, particularly filaments such as stamens, connected into one or more , whether in the form of bunches or tubes, such as is commonly seen in families such as adelphiae Malvaceae. Usage of the term is not consistent; some authors include closely bunched filaments, while others include only adelphiae in which filaments are connected at their bases at least. See for example, Sims: "...the filaments are so closely pressed that they have the appearance of being monadelphous...". Compare derived terms such as  , having stamens growing in a single bunch or tube, for example in monadelphous , and Hibiscus growing in two bunches. diadelphous adherent Slightly united to an organ of another kind, usually to a part of another whorl, e.g. a sepal connected to a petal. Contrast . adnate adnate Grown from or closely fused to an organ of a different kind, especially along a , e.g. a stamen fused to a petal. Adnate anthers have their halves attached to the filament through most of their length. (Contrast margin .) connate adventitious Produced in an unpredictable or unusual position, e.g. an adventitious produced from a bud rather than from the more typical stem of a axil . Adventitious leaf may develop from roots of nodes stems of some plant species, or from the prostrate rather than from the hypocotyl of a germinating radicle . monocotyledon adventive Introduced accidentally (usually referring to a ). weed aerial Of the air; growing or borne above the surface of the ground or water. aestivation The arrangement of and sepals or their lobes in an unexpanded flower petals . Contrast bud . vernation aff. (affinis) With affinity to others, akin to; often used for a provisionally recognized but unnamed taxon considered close to that name, perhaps a hybrid or extreme variant. aggregate fruit A cluster of formed from the free fruits of a single flower, e.g. a carpels blackberry. Compare . multiple fruit agochoric Plants that are spread through accidental transport. agricultural weed See . weed agriophyte Plant species that have invaded native vegetation and could survive there without human intervention. They are established there in natural habitats, remaining part of natural vegetation even after human influence has ceased, and are independent of humans in their continued existence.  agrophic a comb-like series of veins forking from a single side of a primary or secondary vein alate Having a or wings. wing albumen An older name for the of flowering plants. Except for being a endosperm storage tissue for nutrients, it is not at all like the albumen ( egg white) of animal embryos. albuminous (of ) Containing seeds . endosperm -ales A suffix added to the stem of a or descriptive name to form the name of a taxonomic generic name . order alien Any plant introduced to an area outside its natural range. Often used interchangeably or in combination with foreign, , exotic non-, and native non-. indigenous alkaloid Any of a loosely defined class of organic compounds found in the tissues of many species of plants. Alkaloid molecules have one or more alkaline-reacting nitrogen atoms in their carbon structures. Many alkaloids are commercially important as drugs or poisons, e.g. caffeine, morphine, quinine, and strychnine, each of which occurs naturally in certain plants. alternate 1. (adj.) (of or leaves s) Borne singly at different levels along a flower , including spiralled parts. Contrast stem . opposite 2. (prep.) Occurring between something else, e.g. alternating with stamens . petals ament A synonym of . catkin amphitropous (Of an ) Bent so that both ends are near each other. Contrast ovule , anatropous , and campylotropous . orthotropous amplexicaul With the base dilated and clasping the stem, usually of leaves. amylum star a vegetative propagative body filled with starch (amylum) and located around the lower nodes of certain s. stonewort anastomose Branching and then rejoining, as with . leaf venation anastomosis A connection or fusion of two or more that are normally diverging or branching, thereby forming a network. veins anatropous (of an ) Inverted so that the ovule faces the micropyle (this is the most common ovule orientation in flowering plants). Contrast placenta , amphitropous , and campylotropous . orthotropous androdioecious Having flowers and male flowers on separate individuals. Contrast bisexual , andromonoecious , polygamodioecious , and polygamomonoecious . polygamous androecium A collective name for the male reproductive parts of a ; the flower of a flower considered collectively. Contrast stamens . Abbreviated gynoecium A; e.g. A 3+3 indicates six stamens in two . whorls androgynophore A stalk bearing both the and androecium of a flower above the level of gynoecium of the insertion . perianth androgynous Having male and female flowers in the same . inflorescence androphore The stalk or column supporting the in certain flowers. stamens andromonoecious Having flowers and male flowers on the same individual plant. Contrast bisexual , androdioecious , gynomonoecious , polygamodioecious , and polygamomonoecious . polygamous anemophilous Adapted to by pollination wind. anemophily Adaptation to by pollination wind. angiosperm A flowering plant; a plant with developing seeds enclosed in an . ovary anisomery The condition of having a floral with a different (usually smaller) number of parts from the other floral whorls. whorl anisotomic Branching, with branches having unequal diameters, such as a trunk and its branch. Contrast . isotomic annual A plant that completes its life cycle (i.e. germinates, reproduces, and dies) within a single year or growing season. annulus 1. A ring-like structure; in the form of a ring. bristles are sometimes attached to a ring called an annulus or disk at the top of the Pappus beak. In some achene grains, the exine around the apertures is either thicker or thinner. In pores, this border is termed an annulus. Certain flowers have ring-like constrictions at the mouth of the flower, e.g. in pollen and Huernia . Aristolochia 2. A ring of specialized cells on the sporangium. anterior Positioned in front of, toward the . Compare apex . distal anthemoid In the Compositae, a with a brush-like tuft of sweeping hairs at the tip of each style branch. style anther The -bearing part of a pollen . stamen antheridium in bryophytes, a specialised gametophytic organ that produces the male gametes antheridiophore In liverworts of the order Marchantiales, a male , a specialised, stalked structure that bears the gametophore antheridia antherode A sterile of a anther . staminode anthesis 1. (of a flower) The period during which is presented and/or the pollen is receptive. stigma 2. (of a flowering plant) The period during which flowers in anthesis are present. Not defined for some cases, such as when pollen is released in the bud. anthocarp A type of in which some part of the fruit persists attached to the flower , e.g. in pericarp Nyctaginaceae. anthophore A stalk-like structure, located between the internode and the other parts of the flower. calyx anticlinal Pointing up, away from, or perpendicular to a surface. Contrast . periclinal antrorse Directed toward or upward, e.g. of hairs on a stem. Contrast . retrorse apetalous Lacking . petals apex
The tip; the point furthest from the point of attachment.
aphananthous (of flowers) Inconspicuous or unshowy, as opposed to or showy. phaneranthous aphlebia
Imperfect or irregular leaf endings commonly found on ferns and fossils of ferns from the
Carboniferous Period. apical At or on the of a structure, usually a apex , a shoot , or the stem of a tree, e.g. an apical trunk or an apical meristem . bud apiculate especially of leaves, ending in a short triangular point. apiphily A form of whereby pollination is distributed by pollen honey bees. apo- A prefix meaning "away from, separate, without". apocarpous (of a ) Consisting of one or more gynoecium which are free from one another (or almost so), e.g. in members of the carpels Ranunculaceae and Dilleniaceae. apomixis
A type of
asexual reproduction whereby viable or seeds are produced asexually, without spores fertilization, such that the genetic material they contain is a clone of the parent's genetic material. A plant produced in this way is called an apomict. apomorphy In cladistics, a "different form" from the form of an ancestor (i.e., an innovation) of use in determining membership in a . clade apopetalous Having separate , not fused ( petals ). sympetalous apophyllous or other segments free, not united. Compare perianth , symphyllous , gamophyllous . polyphyllous apophysis 1. The external part of a . cone scale 2. An outgrowth of an organ or an enlargement of a . stem appendage A secondary part attached to a main structure; an external growth that seldom has any obvious function, hence . appendiculate appendiculate Having the nature of or bearing s. appendage appressed Pressed closely but not fused, e.g. leaves against a stem. aquatic plant A plant whose natural habitat is water, living in or on water for all or a substantial part of its lifespan; generally restricted to fresh or inland waters. arachnoid Cobwebby, from being covered with fine white hairs. arborescent -like in growth or general appearance. Tree arboretum
A taxonomically arranged collection of
. trees archaeophyte A non- plant that has nonetheless been present in a particular geographic area for some time. Contrast native . neophyte archegonium A multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete. The corresponding male organ is called the antheridium. archegoniophore In liverworts of the order Marchantiales, a female , specialised, stalked structure that bears the gametophore archegonia and the sporophytes arctotoid In the Compositae, a with a ring of sweeping hairs borne on the shaft of the style proximal to the style branches. style areolate Having or being composed of , as an areolate areoles crustose lichen. areole 1. A space between the threads of a net, e.g. that part of a surface defined by each of the elements of a leaf network; as with cacti, the area between the veinlets of a leaf. vein 2. A structure on the stem of a node cactus; the region of a cactus upon which spines and flowers are borne. 3. In lichenology, a polygonal piece of a surface where a thallus crustose lichen is broken up like old dried and cracked paint, or like the polygonal "islands" of dried mud in a dry lake bed. aril A membranous or fleshy formed by expansion of the appendage which partly or wholly covers a funicle , e.g. the fleshy outer layer of seed lychee fruit, or that found in members of the Sapindaceae. aristate With a stiff, bristle-like or tip. awn article A segment of a jointed or of a stem with constrictions between the seeds; an organ part that separates easily from the rest of the organ at a joint or articulation. fruit articulate Jointed; separating freely, leaving a clean scar; e.g. the of certain ferns where they join the fronds . rhizome ascending 1. (of a ) Spreading horizontally, then directed upward; an ascending stem is more or less stem near its base, then prostrate . erect 2. (of an ) Attached somewhat above the base. ovule asexual reproduction Reproduction that does not involve . Often used interchangeably with gametes . vegetative reproduction asperulous Having a rough, sandpapery texture, e.g. some leaf surfaces. asymmetrical or unequal; lacking any Irregular plane of symmetry; e.g. flowers of . Canna attenuate Narrowing gradually. auricle An ear-shaped , particularly a small, roundish, lateral lobe of a appendage or leaf-like organ. leaf awn 1. Any long, bristle-like . appendage 2. In the Poaceae, an appendage terminating or on the back of and/or glumes of some grass lemmas . spikelets 3. In the Geraniaceae, the part of the that remains attached to the style that separates from the carpel carpophore (column). 4. A generally straight, stiff element, varying from stiffly bristle-like to hard and needle-like. In pappus , the awn is the beak of the Strophanthus , seed of the stipe hairs. coma , and an axils bud sprouting from the apical of the shoot of apex . The axillary buds are Searsia angustifolia in scaly dormant , but the apical bud is bare, exposing emerging leaf cataphylls . rudiments axil The upper angle between one part of a plant and another, e.g. the stem and a leaf. axile On an axis; of a , on the central axis of the placenta . ovary axillary Borne in or arising from the , usually referring to the axil of a leaf. axil axis The main of a whole plant or stem ; also, the line along which this stem extends. inflorescence B Baculiform desmid in genus Closterium Barbs
occur on the spines of some species of cactus, as shown here enlarged.
Structure of a compound leaf biternate of a mature Buttress root elm baculiform Rod-like; longer than wide. Compare . cylindrical barb A rear-facing point, as in a fish hook. barbed Having pointing in one direction. barbs barbellate Having hairs ( barbed barbellae). bark The protective external layer of tissue on the and stems of roots trees and shrubs; includes all of the living and non-living tissue external to the woody . cambium basal Situated or attached at the base. basifixed Something attached by its base, e.g. an attached to the anther . Compare filament . dorsifixed basipetal Developing sequentially from the toward the base (i.e. with the youngest toward the base), e.g. of flowers in an apex . Also, moving from leaves to roots, e.g. of molecular signals in plants. inflorescence bathyphyll A specialized produced at the base of a plant, usually when the plant is immature, and which serves to anchor the plant to a substrate; especially notable in the fern leaf . Contrast Teratophyllum . acrophyll beak A prominent, pointed terminal projection, especially of a or carpel . fruit berry A type of indehiscent with the fruit immersed in the pulp, e.g. a seeds tomato. bi- A prefix meaning "two"; e.g. , having two sulci or grooves. bisulcate biennial A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal of leaves in the first year and then flower and fruit in the second year. rosette bifid Forked; cut in two for about half its length. Compare . trifid bifoliate (of a ) Having precisely two compound leaf , usually in a symmetrical pair, e.g. a leaf of leaflets . Compare Colophospermum mopane lobed leaf, e.g. most species of jugate . Bauhinia bifusiform with a pinch in the middle. Fusiform bilabiate Having two lips, e.g. the form of the in many petals flowers. irregular bilateral 1. Having two distinguishable sides, such as the two faces of a leaf. dorsiventral 2. Arranged on opposite sides, e.g. on a leaves ; cf. stem and distichous . opposite 3. Bilaterally symmetrical, as in a leaf with a symmetrical outline. biloculate Having two , e.g. in loculi or anthers . ovaries binomial Making use of names consisting of two words to form the scientific name (or combination) in a Latin form. For example, where the first is the name of the to which the genus belongs, and the second is the species given to that species to distinguish it from others in the same genus. specific epithet binomial nomenclature The system of nomenclature in which the scientific name of a (and not of a taxon at any other rank) is a combination of two names, the first name being the species . The second name is referred to botanically as the generic name . Note that the two names together (not just the second name) constitute the species name. specific epithet bipinnate Doubly ; e.g. a pinnate leaf with individual compound pinnately divided. leaflets bipinnatisect A pinnatisect with deeply dissected segments. leaf bisexual Bearing both male and female reproductive organs; usually, flowers with both and stamens ; synonymous with carpels , hermaphrodite , and synoecious . Bisexual flowers occur only on monoclinous plants. See also monoecious , androgynous , and monoicous plant reproductive morphology. bitegmic (of an ) Covered by two ovule . Contrast integuments . unitegmic biternate , with each division divided into three. Ternate bivalve Having two valves or hinged parts. Contrast . trivalve blade The or flattened part of a lamina , excluding the stalk or leaf . petiole bloom A fine white or bluish waxy powder occurring on plant parts, usually stems, leaves, and fruits. It is easily removed by rubbing. bole The of a tree, usually the portion below the lowest branch. Compare trunk . canopy bostrychoid Arranged on a conical surface (like a snail shell); used to describe s in which the inflorescence are arranged in an almost helical manner on the outside of a long, tapering, conical buds . rachis bract A modified associated with a leaf or flower and differing in shape, size, or colour from other leaves (and without an inflorescence axillary ). bud bracteate Possessing . bracts bracteole A small borne singly or in pairs on the bract or pedicel ; synonymous with calyx . bractlet bracteolate Possessing s (bractlets). bracteole bractlet See . bracteole branchlet A small . branch brevideciduous A plant that loses all of its leaves only briefly before growing new ones, so that it is leafless for only a short time, e.g. approximately two weeks. bristle A straight, stiff hair (smooth or with minute teeth); the upper part of an (when the latter is bent and has a lower, stouter, and usually twisted part, called the awn ). column brochidodromous Pinnate in which the leaf venation s do not terminate at the leaf secondary vein , but are margin in a succession of prominent joined arcs. brochus
Width of one lumen of a
grain reticulum and half of the width of the surrounding muri (walls), hence pollen heterobrochate and homobrochate, where the lumina are of different or similar sizes, respectively. bryophyte Informally, any plant that is a moss, hornwort, or liverwort. Formally, these plants are placed in three separate divisions: hornworts ( Anthocerophyta), liverworts ( Marchantiophyta), and mosses ( Bryophyta). bulb A thick storage organ, usually underground, consisting of a stem and leaf bases (the inner ones fleshy). bulbel A arising from another bulb. See bulb . bulblet bulbil A small, deciduous or bulb formed in the tuber of a leaf or axil ; a means of vegetative propagation. pinna bulblet A arising from another bulb; a bulb . bulbel bullate Having rounded or globular blisters on the surface. burr 1. A prickly . fruit 2. A rough or prickly propagule consisting of a or fruit and associated floral parts or seed . bracts buttress root A growing from an above-ground stem or trunk, and providing support, e.g. commonly of root . Ficus macrophylla byssoid A growth form of a lichen that is whispy, like thallus teased wool. C has a Dianthus chinensis growth habit. caespitose tissue of Callus growing on a nutrient medium in Nicotiana tabacum plant tissue culture}}
Structure of flower of an orchid in genus
Praecoxanthus, with the callus labelled
callus of a floret of the grass species Chrysopogon filipes Dormant leaf buds of deciduous trees are commonly protected by imbricate that are shed when the bud sprouts. cataphyll s
grows largely above the soil surface. Many species that form caudices grow them underground.
growing as a
on an overhanging cliff
are simple in shape. Chloroplasts of
are helical within the tubular cells of their algal filaments.
The so-called "fleshy leaves" of cacti such as this
, branches. The true leaves are the spines growing on the cladodes, which on this young cladode are still fleshy.
with red Curcuma pseudomontana coma bracts flowers with basal Pfaffia gnaphalioides coma hairs Coma atop , bearing sterile flowers Muscari armeniacum
flower split open between two petals to show the
formation of the
tube. Compare the
attachment of the stamen bases to the matching petals.
, one entire in its
, one partly peeled to show tunic
s, and one split to show inner structure
flower is a ring of purple filaments between the petals and the stamens.
of seedlings of
. One plant shows the first new leaves above its cotyledons; the rest show various younger stages of emerging cotyledons.
Crustose lichens on a wall Mimetes cucullatus
, so named for the hooded,
shape of its white flowers
Quercus rubra B: Quercus trojana C: Fagus sylvatica D: Castanea sativa is commercially grown for the aesthetic appearance of its brightly colored, Euphorbia milii bract -like structures called , which sit below the cyathophyll s inflorescence . C, C−, C+ In lichenology, "C" is an abbreviation for the test result of placing 5% solution of calcium hypochlorite or sodium hypochlorite (e.g. household bleach without additives) on the or cortex of a medulla lichen, to note the change in color, with no reaction noted as "C−", and production of a bright colour noted as "C+". caducous Falling off early, e.g. the of poppies, which fall off when the sepals begin to open. Compare petals and persistent . fugacious caespitose Tufted or turf-like, e.g. the growth form of some grasses. calcarate possessing a . spur calcareous A soil type or a lichen substrate rock type that is rich in or largely composed of calcium carbonate. callose Hardened; thickened; callous. callus
A protruding mass of tissue 2. Undifferentiated tissue growth formed in response to wounding; may be grown in vitro. 3. In orchids, fleshy outgrowths from the which can be variously shaped from labellum to plates. papillae 4. In grasses, a hardened extension from the base of a (formed from the floret joint and/or the base of the rachilla ) which may or may not elongate and is often covered in hairs or bristles. lemma calyciflorous Having and petals attached to the stamens . calyx calycophyll A leaf-like structure formed from a or sepal lobe which enlarges, usually many-fold, before or after calyx , especially when most of the other sepals or calyx lobes retain their original size. More extreme than an anthesis calyx, calycophylls are found in accrescent Rubiaceae. Compare and semaphyll . pterophyll calyculate Having an . epicalyx calyculus 1. A cup-shaped structure formed from resembling an outer bracts . calyx 2. In some Asteraceae, a circle of bracts below the . involucre calyptra A hood or lid. See . operculum calyx
A collective term for the
of one flower; the outer sepals of a flower, usually green. Compare whorl . corolla calyx tube A tube formed by the fusion of the sepals ( ), at least at the base. calyx cambium A tissue layer that provides partially undifferentiated cells for plant growth. campanulate Bell-shaped. camptodromous Pinnate in which the venation curve toward the margins, in some cases becoming nearly parallel with them, and not reconnecting with other veins to form loops. secondary veins campylotropous When the is oriented transversely (i.e. with its axis at right angles to its stalk) and with a curved ovule embryo sac. Compare , amphitropus , and anatropous . orthotropous canaliculate Channelled; having a longitudinal groove. canescent Approaching white in color, as in a leaf covered with white down or wool. canopy The branches and foliage of a tree; the . Also refers to the protective upper layer of a forest. Compare crown . trunk capillary 1. A tube, pore or passage with a narrow, internal cross-section. 2. Slender; hair-like. capitate 1. (of an ) Having a knob-like head, with the flowers unstalked and aggregated into a dense cluster. inflorescence 2. (of a ) Like the head of a pin. stigma capitulum A dense cluster of or sessile subsessile or flowers , e.g. a flower florets in the daisy family, head Asteraceae. See . pseudanthium capsule A dry formed from two of more united fruit and carpels when ripe (usually by splitting into pieces or opening at summit by teeth or pores). dehiscing carduoid In the Asteraceae, having a with a ring of sweeping hairs borne on the shaft of the style below the style branches. style carina See . keel carinal canal A longitudinal cavity in the of stems and extinct Equisetum Equisetopsida, coinciding with a ridge in the stem surface. carneous Flesh-coloured, especially as applied to some flowers. carnose, carnous Fleshy or pulpy in texture, especially as applied to some tissues or organs. Contrast and coriaceous . corneous carpel The basic female reproductive organ in s, either consisting of a single angiosperm or a single sporophyll of a compound locule , with a ovary and a style . The stigma is the collective term for all of the carpels of a single gynoecium . flower carpopodium On (Cypselas), an elongation of the base of the achenes which looks distinct; the gynoecium , where the achene is separated from the abscission zone . receptacle cartilaginous Hard and tough; gristly. Compare and corneous . coriaceous caruncle A small piece of flesh-like tissue, typically lumpy or warty, growing on the near the testa . Contrast hilum . aril caryopsis A dry, , one-seeded indehiscent in which the fruit is closely fused to the fruit wall, e.g. in most grasses. seed coat Casparian strip A continuous band of suberin in the radial primary cell walls of the in vascular plant stems and roots that forms a permeability barrier to the passive diffusion of external water and solutes into the vascular tissue. endodermis cassideous Hood-, helmet- or bonnet-shaped; generally referring to floral anatomy, e.g. in the flowers of , Aconitum , etc. Satyrium casual alien An exotic plant that appears with no apparent human assistance but does not develop a sustained population(s), or one that persists only by repeated new introductions. Compare . alien cataphyll Any plant structure which is morphologically a but which has at most an incidental or transient leaf function. They are either shed when their main function has been completed, or are incorporated into structures where, when dead, they serve a protective or supportive purpose. photosynthetic catenulate In the shape of a chain; formed of parts or cells connected as if chained together, e.g. some diatoms, algae, and cyanobacteria such as . See also Anabaena . concatenate catkin A , usually pendulous, in which the mostly small spike are flowers and without a conspicuous unisexual , e.g. in perianth willows, poplars, oaks, and casuarinas. The individual flowers often have scaly and are generally bracts . Catkins are usually shed as a unit. wind-pollinated caudate Having a narrow, tail-like appendage or tip, e.g. a . Contrast drip tip , acuminate , and cuspidate . mucronate caudex
of a plant, especially a stem one; also used to mean a woody , or particularly a rootstock stem structure or storage organ from which new growth arises. Compare basal . lignotuber caudiciform -like or Stem -like; sometimes used to mean " caudex pachycaul", meaning "thick-stemmed". caulescent possessing a well-developed stem above ground, similar to . cauline Antonym of (lacking an apparent stem) acaulescent cauline Borne on an aerial or stem , as with leaves, flowers, or fruits (when applied to the latter two organs, usually referring to older stems; synonymous with caulis ). cauliflorous cell 1. The basic, microscopic unit of plant structure, generally consisting of compartments in a viscous fluid surrounded by a . cell wall 2. A cavity of an or anther . ovary cenanthous (of a ) Lacking both perianth and stamens , i.e. a flower with neither pistil nor androecium . gynoecium centrifixed Of a two-branched organ attached by its centre, e.g. a hair or . anther ceraceous Having a waxy appearance, colour, or texture, e.g. flowers of many species of , and the waxy fruit of some species of Ceropegia . Myrica cernuous Nodding, falling headlong or face down; inclined, stooping, or bowing forward. Applied to many species with a nodding, stooping , such as many habit and Narcissus species. Many plant species bear the Dierama " specific epithet cernua". cespitose An alternative spelling of , meaning Tufted or turf-like, e.g. the growth form of some grasses. caespitose chamber A cavity of an . ovary channelled Sunken below the surface, resulting in a rounded channel. chartaceous Having a papery texture. chasmogamous Of flowers that are pollinated when the is open. Compare perianth . cleistogamous chasmophyte A plant adapted to growing in crevices or hollows, such as in cliff faces. Compare . cremnophyte   chimera An individual composed of two or more genetically distinct tissues, most commonly as a result of a and sometimes by mutations that occur during cell division or cellular transfers during seed development. graft chiropterophilous by Pollinated bats. chlorophyll Any of a variety of different chemical pigments in s that are essential for chloroplast . photosynthesis chloroplast An organelle present in plant cells which contains . chlorophyll chlorosis An abnormal lack or paleness of color in a normally green organ. cilia
Very small hairs or hair-like protrusions more or less confined to the
of an organ, as with eyelashes; in motile cells, minute, hair-like protrusions which aid motility. margins circinate Spirally coiled with the tip innermost, e.g. circinate of the developing vernation of most ferns. fronds cirrhose (of a leaf) Ending in a at the tendril . apex cladode A photosynthetic or branch , often leaf-like and usually with foliage leaves either absent or much reduced. Compare stem . phyllode class The principal category for taxa ranking between and division . order clathrate Shaped like a net or lattice; pierced with apertures, as with a cage. clavate Club-shaped. clavuncula In the Apocynaceae, an enlarged, drum-shaped of which the sides and lower surface are the receptive zones. Coherent with the stigma or not. anthers claw 1. A narrow, stalk-like, portion of a basal , petal , or sepal . bract 2. In , the united portion of a Melaleuca bundle. stamen cleistogamous Having flowers which self-pollinate and never open fully, or which self-pollinate before opening. Compare . chasmogamous climber A plant growing more or less by leaning on or twining around another structure for support, or by clinging with erect . tendrils cline
A continuous morphological variation in form within a species or sometimes between two species.
clone A plant derived from the asexual vegetative reproduction of a parent plant, with both plants having identical genetic compositions. coalescent Having plant parts fused or grown together to form a single unit. cochleariform Concave and spoon-shaped. cochleate Coiled like a snail's shell. coenobium An arranged colony of algae that acts like a single organism. coenocyte A single cell with multiple nuclei, formed when nuclear division was not followed by cytokinesis. coleoptile One type of in the structure of sheath ous seeds. The coleoptile is a protective sheath or cap ( monocotyledon ), generally more or less pointed, that covers the monocotyledonous pileus as it emerges from the soil. It generally turns green and contributes to photosynthesis until its function is superseded by the main growth of the seedling. Contrast this with the plumule , which remains underground until it is superseded as the roots emerge. coleorhiza coleorhiza One type of in the structure of sheath ous seeds. The coleorhiza connects the coleoptile to the monocotyledon and protects the monocotyledonous radicle during germination. Unlike the coleoptile, the coleorhiza is associated with the root and does not emerge from the soil during germination. Contrast radicle . coleoptile collenchyma A specialized tissue consisting of living cells with unevenly thickened cellulose and pectin that performs a support function in organs such as leaves and young stems that are composed of primary plant tissues. cell walls colleter A multicellular, hair that usually produces a mucilaginous substance and is located on glandular , sepals , or stipules , or on nearby parts of petioles ; commonly found on plants in the order stems Gentianales. columella In flowering plants, the central axis of the or cone , e.g. in fruit . Callitris column 1. A structure extending above the and incorporating the ovary and style also known as the stamens , e.g. in gynostegium orchids and milkweeds. 2. In grasses, the lower, stouter, and usually twisted part of an , distinct from the slender upper part or bristle. awn columnar Shaped like a column. coma 1. A tuft of hairs from or testa at one or both ends of some seeds, e.g. in funiculus , Strophanthus , or Asclepias . Alstonia 2. Sterile , e.g. in bracts , Curcuma , or Ananas . Eucomis 3. Sterile , e.g. in flowers and Muscari , at the Leopoldia of some apex . inflorescences 4. A tuft of hairs at the base of some flowers, e.g. in . Pfaffia gnaphalioides 5. A tuft of hairs at the apex or base of some . spikelets 6. An tuft of hairs in inflorescences in some axil Poaceae, e.g. in . Eragrostis comata commercial name A name often of no botanical standing and not governed by the ICNCP. The term generally applies to names such as Trademark Names, names covered by Plant Breeders Rights, Patents and Promotional Names, which are often used to enhance the sale of a plant. commissure The seam or face at which two adhere. See also carpels and fissure . suture An ecological assemblage of plants that characteristically occur together. compound Composed of several parts, e.g. a composed of multiple leaf , a leaflets composed of multiple gynoecium , or an carpels made up of multiple smaller inflorescences. inflorescence compound palmate Having that radiate from a central point (usually at the top of a leaflets ), like spread-out fingers radiating from the palm of a hand. Compare petiole . palmate compressed Flattened lengthwise, either laterally (from side to side) or dorsally (from front to back). concatenate Joined together in a chain-like form. See also and concatenate . catenate concolorous Having the same colour throughout; uniformly coloured. conduplicate Arranged such that two sides of a flat surface are folded along the midline to face each other. See also , ptyxis , and aestivation . vernation cone A type of , usually fruit , woody to ovoid , including globular , scales , or bracts arranged around a central axis, e.g. in bracteoles gymnosperms, especially conifers and . Casuarina conflorescence A rarely used term describing substantial differences between the overall structure of an and that of its individual branches, e.g. the bottlebrush multiple-flower head of members of the genus inflorescence . Callistemon connate Fused to another organ (or organs) of the same kind, e.g. in a petals gamopetalous tube. Compare corolla . adnate connective The part of an that connects the anther cells. anther connivent Coming into contact or converging. conspecific Belonging to the same . species contiguous Adjoining, touching, but not united. contort (of or sepals ) A type of imbricate petals in which one side of each segment overlaps one of the adjacent segments and the other side is overlapped by the other adjacent segment. See aestivation . convolute contorted Twisted out of the normal shape. convolute 1. Referring to the arrangement of floral or foliar organs in a when each organ or segment has one edge overlapping the adjacent organ or segment; a form of bud arrangement. See imbricate . contort 2. (of ) A type of leaves in which one leaf is rolled up inside another. vernation 3. A type of vernation of two leaves at a , in which one half of each leaf is exposed and the other half is wrapped inside the other leaf. node corcle A plant , embryo , or plumule plus plumule . radicle cordate Heart-shaped, with the notch lowermost; of the base of a , like the notched part of a heart. Contrast leaf . obcordate coriaceous Leathery; stiff and tough, but flexible. Compare . corneous corm A fleshy, swollen base, usually underground and functioning in the storage of food reserves, with stem naked or covered by very thin scales; a type of buds . Adjectives derived from "corm" include "cormose" and "cormous". rootstock corneous Horny in texture; stiff and hard, but somewhat tough. Compare . coriaceous corolla A collective term for the of a petals . Compare flower . calyx corona 1. In flowering plants, a ring of structures that may be united in a tube, arising from the or corolla of a flower and standing between the perianth lobes and the perianth . The trumpet of a stamens daffodil is a corona. 2. In grasses, a hardened ring of tissue surmounting the in some species. lemma cortex
In lichens, the "skin" or outer layer of
tissue that covers the thallus . medulla lichens have one cortex encircling the branches, even flattened, leaf-like forms; Fruticose lichens have different upper and lower cortices; foliose , crustose , and placodioid lichens have an upper cortex but no lower cortex; and squamulose lichens lack any cortex. leprose corticolous Growing on or on wood with the bark stripped off. Compare bark . lignicolous corymb
with branches arising at different points but reaching about the same height, giving the flower cluster a flat-topped appearance. inflorescence costa A . rib costapalmate Having a definite (midrib), unlike the typical costa or fan leaf, but with the palmate arranged radially as in a palmate leaf. leaflets cotyledon The primary leaf or leaves of a plant embryo which upon germination develops into the seed-leaf or the first set of leaves. craspedodromous Pinnate in which the venation terminate at the secondary veins , often as teeth. margins crateriform In the shape of a saucer or shallow cup; hemispherical or more shallow. cremnophyte A plant adapted to growing on, especially hanging from, cliff faces or crevices. Compare . chasmophyte   crenate Having blunt or rounded teeth; scalloped. crenulate Minutely scalloped. crisped Finely curled, as with the edges of leaves and petals. cristarque cell A sclereid which contains a and has the druse lignin deposited excentrically on the to form a cup shape, or in cell wall cross-section, a ∪-shape. crown See . canopy cross To make something interbreed; the act of hybridization. cruciform Cross-shaped. crustaceous Hard, thin and brittle. crustose Forming a closely applied surface layer or crust. cryptogam Any of the "lower plants" which produce spores and do not have , stamens , or ovaries ; literally, plants whose sexual reproductive organs are not conspicuous. This group typically includes the seeds ferns, bryophytes, and algae, and sometimes fungi (including lichenized fungi). Compare . phanerogam cucullate Hood-like or hooded, commonly referring to the shape of leaves or petals, e.g. . Similarly derived terms include Pelargonium cucullatum cuculliform and cuccularis. culm In grasses, sedges, rushes, and some other s, an monocotyledon aerial bearing the stem , extending strictly from the base of the plant to the lowest inflorescence (or base of the inflorescence). involucral bract cultigen A plant whose origin or selection is primarily due to intentional human activity. cultivar A term derived from "cultivated variety" denoting an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical, or other). When reproduced (either sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant that is of horticultural interest or value. Cultivar names are written with single quotation marks around them, e.g. 'Blue Carpet' or 'Alba'. All new names established after 1 January 1959 must be in common language (that is, not in Latin), but names established in Latin prior to this date are retained in Latin form. cultivar epithet The defining part of a name that denominates a . Cultivars are designated by fancy (q.v.) epithets appended either to the scientific name or to the common name of the taxon to which they belong; they are not italicized but placed in single quotation marks, e.g. cultivar Rubus nitidoides 'Merton Early'. 'Merton Early' is the cultivar epithet. cuneate Wedge-shaped, with straight sides converging at a base. cupule A cup-shaped structure composed of coalescent , such as the cup of an bracts acorn. See . calybium cupular Shaped like a . cupule cupulate Bearing . cupules cupuliform Nearly hemispherical, shaped like a cupola or dome. cusp A hard, pointed tip, stiffer and more formidable than a , hence mucro . cuspidate cuspidate Tipped with a , as with some leaves. cusp cuticle A waterproofing layer covering the of epidermis plant surfaces and composed of the polymers aerial cutin, and/or cutan and waxes. cutting An tip of apical structure, shoot , or root which is cut from a plant and used for asexual vegetative propagation. leaf cyathium
of inflorescence flowers surrounded by unisexual , especially the flowers of involucral bracts . Euphorbia cyathophyll In , the Euphorbia -like structure on which the bract sits, usually but not always occurring in twos. They may sometimes be brightly colored and confused with involucre . petals cylindrical Rod-like and two to three times as long as wide. Compare . baculiform cynaroid See . carduoid cyme
A type of
in which the main axis and all lateral branches end in a inflorescence (each lateral may be repeatedly branched). flower cymose Having a or cymes. cyme cypsela A type of dry, one-seeded, indehiscent formed from an fruit . inferior ovary D developing in tissue of Dissepiment carpels where they meet to form locules in the capsule of the ovary of Lilium Domatia
at the bases of the thorns of
, the "Whistling Thorn". Note the access holes.
(bilateral) leaves of Dorsiventral Syzygium gerrardii and Triadica sebifera Leaves of have a Epipremnum aureum cuspidate . drip tip deciduous and falling seasonally, as with Dehiscing , bark , or leaves . Contrast petals . persistent declinate Curving downward, and then upward at the tip. Often qualified, e.g. declinate-ascendant. decompound Divided to more than one level, e.g. in leaves, in which the bipinnate of what would otherwise be a leaflets leaf are themselves pinnately divided. pinnate decorticate 1. (intr. v.) To shed the outer bark of a tree, usually seasonally as part of the natural growth cycle. 2. (tr. v.) To strip the peel, crust, bark, or other surface tissues from a plant or from harvested material, such as in extracting fibre from harvested Agave leaves. decumbent Having branches growing horizontally along the ground but which are turned up at the ends. decurrent Extending downward beyond the point of , e.g. when the base of a leaf or a fungal gill is prolonged downward along the insertion in a raised line or narrow wing. stem decussant A synonym of ; the usage decussate decussant is questionable and occurs rarely, probably as an error. The formally correct usage is decussate. decussate with successive pairs borne at right angles to the last; generally applied to the Opposite arrangement of leaves. definite Of a constant number, e.g. twice as many as stamens or petals (or less), or an sepals ending in a inflorescence or an aborted floral flower , typically a bud inflorescence. Contrast cymose . indefinite deflexed Bent downward. Contrast . inflexed dehiscent Breaking open at maturity to release contents; refers e.g. to the opening of to release fruits , of seeds to release anthers , and of pollen to release sporangia . Contrast spores . indehiscent deltoid Shaped like the uppercase Greek letter Δ, i.e. like a more or less equilateral triangle. dendroid -like; branching like a tree. Tree dentate , especially in reference to Toothed leaf . margins denticulate Finely ; a diminutive form of toothed . dentate deserticolous Inhabiting a desert. determinate Limited, usually in growth. Contrast . indeterminate diadelphous Referring to a class of structure in which the adelphous or similar organs are connected in two stamens instead of just one. adelphiae diaspore Any reproductive part of a plant adapted for dispersal and for establishing new plants; may be a disseminule such as a , or other parts such as specialised seed , branches, inflorescences, or fruits. buds dichasium A cymose with all branches below the terminal flower in inflorescence opposite pairs. Compare regular and monochasium . pleiochasium dichlamydeous Having a which is divided into a separate perianth and calyx . Compare corolla . homochlamydeous dichotomous Forking into two equal branches. This may result from an equal division of the growing tip, or may be sympodial, in which the growing tip is aborted and replaced. Typically refers to mode of branch growth, as in , but also to other organs, such as the Aloidendron dichotomum venation patterns on leaves, the thorns of various species of (which morphologically are branches), and the Carissa or thalli hyphae of various algae and fungi. dicotyledon
A flowering plant whose embryo has two or more
(seed leaves). Contrast cotyledons . monocotyledon digitate With segments spreading from a common centre, like the fingers of a hand. See also and palmate . palmatisect digitiform shaped like a finger. dimorphic Occurring in two different forms (with respect to shape and/or size), e.g. of , stamens fronds, or leaves. See also (having a single form) and monomorphic (having many forms). polymorphic dioecious (of vascular plants) Having male and female reproductive structures which develop only on different individuals and never on the same individual. Contrast . monoecious dioicous (of a bryophyte ) Having male and female reproductive structures which develop only on different individuals and never on the same individual. Contrast gametophyte . monoicous diploid Having two complete sets of chromosomes in the nucleus of a cell, i.e. one set from each of the parental sporophyte . This is often expressed symbolically as gametes 2n, where n = the number of chromosomes in the gamete. haploid diplostemonous Having arranged in two stamens , with the outer whorl alternating with the whorls while the inner whorl is opposite the petals. Compare petals and obdiplostemonous . haplostemonous disc
A plate or ring of structures derived from the
, and occurring between receptacle of floral parts. In some groups, especially whorls Sapindales, the is in the form of a prominent disk. In nectary daisies, the central part of the is a disk, hence flowers borne there are called capitulum . disk flowers or florets discoid Resembling a disc or plate, having both thickness and parallel faces and with a rounded margin. Also used to describe the flower of head Asteraceae where there are no ray florets but only disc florets. discolorous (of ) Having upper and lower surfaces of different colours. leaves disjunct Occurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations with sufficient distance so as to preclude gene flow between them. disk floret A occurring most typically in the floret of the disk of flowers in the family capitulum Asteraceae, and to some extent in other plants that bear a flowering head with a disk, such as . Scabiosa dissected Deeply divided; cut into many segments. dissepiment A partition or septum in a plant part, usually referring to septa between the of loculi or of other fruits with multiple partitions. capsules distal Remote from the point of origin or attachment; the free end. Contrast . proximal distichous Arranged in two opposite rows (and hence in the same plane). distinct Separate or free; not united. distyly The condition in which the flowers of a species occur in two forms that differ only by the length of the and style , and flowers of only one of these forms appear on any one plant. Compare stamens . heterostyly diurnal Of the day; occurring or opening in the daytime. divaricate Wide-spreading. divergent Spreading in different directions, generally upward. division A taxonomic rank below in the standard taxonomic hierarchy. "Division" is generally used only for plants, and is the approximate botanical equivalent of the term kingdom , which is used for animals and other kingdoms. phylum domatia
Any hollow structure formed by a plant that is inhabited by animals such as ants or mites.
dorsal From Latin dorsum, a ridge or the back of an animal. Partly because the term originally referred to animals rather than plants, usage in botany is arbitrary according to context and source. In general "dorsal" refers to "the rear or back or upper surface", but in botanical usage such concepts are not always clearly defined and may be contradictory. For example: Derived or related terms include facing away from the axis ( ) in a lateral organ of an erect plant abaxial facing away from the substrate in any part of an erect plant, for example the upper surface of a more or less horizontal leaf ( ) or the upper part of the crown of the plant adaxial facing away from the substrate in a or climbing plant or floating leaves such as those of prostrate Nymphaea. dorsad, "toward the dorsal", and dorsum, "the dorsal part of the organ or organism as a unit". Related anatomical terms of location include , ventral . lateral dorsifixed Attached at or by the back, e.g. on a anthers . filament dorsiventral Having structurally and visibly different upper and lower surfaces, e.g. some leaves. Compare and bilateral . isobilateral drip tip A long, narrow, , acuminate , or caudate extension at the tip of a cuspidate or leaf . Commonly an adaptation to rainy conditions, as it promotes shedding of water by its dripping from the narrow tip. The term "drip tip" is not anatomically descriptive in the way that say, acuminate or cuspidate, are; rather it is a description of the functional shape that aids dripping, irrespective of the specific geometry of the shape itself. leaflet drupe A type of succulent formed from one fruit ; the single carpel is enclosed by a stony layer of the fruit wall, e.g. in peaches and olives. Also called a seed . kernel drupelet A small formed from one of the carpels in an drupe flower. Drupelets usually form a apocarpous , as in compound fruit , but they may become widely separated, as in Rubus . Ochna druse A globular mass of calcium oxalate crystals, usually with the crystals radiating from an organic core. E
Plants of the genus
bear seeds with attached
, which have various functions, commonly attracting ants. On some
species, elaiosomes that attract ants also repel mice.
at their tips—flowers in the middle of the inflorescence have slightly emarginate petals, whereas flowers at the periphery are so deeply emarginate as to be almost cleft in two.
emerging from the upper surface of the sprouting date seed is tiny in comparison to the
, its main food supply, which comprises almost all of the rest of the seed.
Water lilies and reeds represent two ecological categories of
The enlarged calyx and smaller of epicalyx Hibiscus sabdariffa Shoots from buds on epicormic Eucalyptus following a bushfire Seeds or fruits are dispersed by when they stick to the fur of animals. epizoochory The bases of leaves enclose later leaves on the stem. equitant -eae A suffix added to the stem of a to form the name of a generic name , e.g. tribe → Aster Astereae. ebracteate Lacking ; synonymous with bracts ebracteolate. ecological amplitude The range of environmental conditions in which an organism can survive. edaphic Of or influenced by the soil. elaiosome An external structure attached to the of many species of plants. Elaiosomes generally look fleshy and in some species they are rich in oils or other nutritious materials. Their functions vary and are not always obvious; commonly they attract ants or other animals that aid in dispersal, but they may also repel other animals from eating the seed. seed  elephophily A form of whereby pollination or pollen are distributed by the feet of elephants, as in spores . Rafflesia arnoldii ellipsoid A three-dimensional shape that is in all sections through the long axis. elliptical elliptical
Planar, shaped like a flattened circle, symmetrical about both the long and the short axis, tapering equally both to the tip and the base;
. oval emarginate Notched at the (notch usually broad and shallow). apex embryo The young plant contained by a prior to seed . germination emergent A plant taller than the surrounding vegetation or, among aquatic plant species, one that bears and commonly flowers above the surface of the water. Aquatic examples include water lilies, reeds, and leaves papyrus. Some pondweeds such as are not emergent until they flower, at which time only their flowers appear above the water surface. Stuckenia enantiostyly The condition in which the protrudes laterally, to the right ( gynoecium ) or to the left ( dextrostyly ) of the sinistrostyly , e.g. androecium . Senna endemic Having a natural distribution restricted to a particular geographic region. Compare . native endocarp The innermost layer of the wall of a fruit; in a , the stony layer surrounding the seed. drupe endodermis The innermost layer of the of cortex vascular plant , also present in the stems of roots pteridophytes. The radial walls are impregnated with suberin to form a permeability barrier known as the Casparian strip. endophloeodal See . endophloic endophloic
crustose lichens) Having the growing within rather than upon the thallus of trees. bark  Compare : 159 and epiphloedal (growing on the surface of wood or bark) and corticolous (growing within rock). endolithic endosperm 1. ( ) A angiosperms nutritive tissue surrounding the of the embryo , usually seed triploid, originating from the fusion of both polar nuclei with one gamete after the fertilization of the egg. 2. ( ) The gymnosperms within the prothallus embryo sac. endospory The production of that germinate into a reduced multicellular spores gametophyte contained within the spore wall. Contrast . exospory ensiform Shaped like the blade of a sword. entire 1. Not divided. 2. (of a ) Smooth and not margin or lobed (though possibly wavy or toothed ). scalloped entomophily A form of whereby pollination or pollen are distributed by spores insects. epecophyte Species of recent appearance, usually numerous and constant in the country, but confined to artificial habitats, such as meadows and ruderal vegetation and are dependent on humans for existence.  ephemeral Short-lived. See also . caducous epicalyx An resembling an outer involucre , e.g. as in calyx . Hibiscus epicarp The outer layer of the wall of a , i.e. the "skin". fruit epicormic Used to refer to , buds , or shoots developing from the old wood of trees, especially after injury or fire. flowers epicotyl The part of the plant axis or stem between the node and the first foliage leaves. cotyledonary epicuticular wax A layer of crystalline or amorphous wax deposited on the surface of the . cuticle epidermis An organ's outermost layer of cells, usually only one cell thick. epigynous Borne on the ; describes floral parts when attached above the level of the ovary and arising from tissue fused to the ovary wall. Compare ovary and hypogynous . perigynous epilithic Growing on stone. Compare , a plant growing on stone. lithophytic epinecral Dead ( ) tissue above the surface of the necral of a cortex lichen. epipetalous Of that are attached to the stamens . petals epipetric Growing on rock or stone, , lithophytic . epilithic epiphloedal Growing on the surface of . Contrast bark (growing inside, not on, the bark) and endophloedal (growing on rock, not bark). epilithic epiphyte A plant, alga or fungus that grows on another plant without deriving nourishment from it but using it for support. epiphytic Of an ; living on the surface of a plant. Compare epiphyte , epilithic . lithophytic episepalous Of that are attached to the stamens . sepals epitepalous Of that are attached to the stamens . tepals epithet The adjectival component in a binomial scientific name, usually more specifically called a ; the final word or combination of words in a name of more than one word (other than a term denoting rank) that denominates an individual taxon. The simplest and commonest example is the second word in a two-word name of a species, such as " specific epithet mirabilis" in . Welwitschia mirabilis epizoochory A type of dispersal that occurs when seeds or seed physically adhere to the outside of vertebrate animal bodies. fruits epruinose Not . pruinose equitant (of a ) Folded lengthwise and clasping another leaf. leaf erect Upright, more or less perpendicular to the ground or point of attachment. Compare (spreading) and patent , between erect and patent. erecto-patent ericoid Having leaves like those of the European heaths ( ); small and sharply pointed. Erica erose (of a ) Irregular as though nibbled or worn away. margin ethelochoric Deliberate introduction by seedlings, seeds or plants in a new habitat by humans. even-pinnate Having an even number of in a leaflets leaf; synonymous with compound . paripinnate evergreen Not ; having leaves all year. deciduous ex In nomenclature, indicating that the preceding author proposed the name but did not legitimately publish it, and that the succeeding author referred to the first author when legitimately publishing the name. See Author citation (botany). exalbuminous In seeds of a given species, having no , i.e. no endosperm , e.g. in albumen Fabaceae and Combretaceae. exocarp The outer layer of the , often the skin of fleshy pericarp . fruits exospory The production of that germinate into free-living multicellular spores gametophytes. Contrast . endospory exotesta The outer layer of the (seed coat). It is derived from the outer testa of the integument . ovule exotic Not native; introduced from another region or country. exserted Projected beyond, e.g. beyond the stamens . corolla tube exstipulate Lacking . stipules Outside the or stamens , usually referring to the location of a nectary disk. androecium extrorse (of anther ) Opening toward the outside of the locules . Contrast flower and introrse . latrorse F Medicago sativa
or lucerne) is an agriculturally important
, grown in large volumes for forage, soil improvement, and other purposes.
is a Letharia vulpina fruticose lichen. F1 hybrid A single cross; a plant breeding term for the result of a repeatable cross between two pure bred lines. F2 hybrid A plant breeding term for the result of a plant arising from a cross between two F1 hybrids; may also refer to self-pollination in a population of F1 hybrids. fabiform Shaped like a kidney bean. facultative Of parasites, optional. Compare . obligate falcate Curved like the blade of a scythe. family A taxonomic group of one or more with features and/or ancestry in common; the term for the principal rank between genera and genus. order farina powdery, pale yellow crystalline secretion consisting of flavonoids in and other species Primula farinaceous Powderiness that is mealy fascicle
A cluster, e.g. a tuft of leaves all arising from the same node.
fasciculate Branching in clusters like a bundle of sticks or needles; having . fascicles faveolate Honeycombed; having regular, angled pits. Compare . foveolate faucal Pertaining to the fauces; located in the throat of a or calyx . corolla fauces The throat of a calyx or corolla; the conspicuously widened portion between the mouth and the apex of the tube. In Boraginaceae, the site of distinctive appendages. felted Covered with very dense, interlocked and matted hairs with the appearance or texture of felt or woollen cloth. female flower See . pistillate flower fenestrate Having translucent areas. See also perforate, with holes. ferruginous Ruddy or rust-colored. fertile Capable of producing fruit; of flowers when they produce seed or of anthers containing pollen. fertilization The union of male and female during sexual reproduction. gametes fiber 1. A fiber cell. 2. Any flexible, strong, stringy, and very elongate structure. fiber cell a type of cell that is found in sclerenchyma, it is much elongated and dies soon after an extensive modification of its cell wall. The cell wall is usually thickly lignified, but is sometimes gelatinous. filament 1. The stalk of a . stamen 2. Any very narrow, thread-like structure that is one or a few cells thick. filamentous consisting of filaments or fibres, hairlike. . filiform thread-like. e.g. stamen filaments, or leaf shapes. fimbria slender hair-like process (plural: fimbriae) . fimbriate Fringed. fissure A split or crack, often referring to fissured bark; a line or opening of dehiscence. fistule A tube-shaped cavity. fistulose Hollow; usually applied to a tube-shaped cavity, as in a reed. flabellate Fan-shaped. flaccid Limp; tending to wilt. Compare . turgid flexistyly Depending on the degree of maturation of the stamens, the style moves up or down (cataflexistyle or (ana-)hyperflexisyle). flexuous flexuose Bent alternately in different directions; zig-zag. floccose Having a soft and woolly covering of hairs. flora 1. all the plants growing in a certain region or country. 2. an enumeration of them, generally with a guide to their identification (e.g. the present volume, the Flora of Victoria, the Flora of New South Wales and so on). In this case 'flora' is written with a capital F. floral envelope See . perianth floral leaves The upper leaves at the base of the flowering branches. floral diagram A graphical means to describe flower structure, usually a schematic cross-section through a young flower. floral formula A description of flower structure using numbers, letters and various symbols. floral tube An imprecise term sometimes used as a synonym of or of hypanthium or of corolla tube . calyx tube floret A small , usually referring to the individual true flowers clustered within an flower , particularly those of the inflorescence grasses and the pseudanthia of daisies. flower The sexual reproductive structure of the , typically with a angiosperms , gynoecium , androecium and an perianth . axis foliate Preceded by a number: having a certain number of leaflets; for example, 3-foliate, "having three leaflets" foliicolous A growth habit of certain lichens, algae, and fungi that prefer to grow on the leaves of vascular plants. follicle A dry fruit formed from one , splitting along a single suture, to which the seeds are attached. Compare pod (of carpel legume). foliole A small leaf-like appendage on the front or back. foliose Leaf-like; flattened like a . leaf forb Any non-woody that is not a flowering plant , grass sedge, or rush. forest Vegetation dominated by trees with single trunks (including closely arranged trees with or without an understory of shrubs and herbs). forma (in common usage, form) A taxonomic category subordinate to species and within the taxonomic hierarchy, below (varietas), and usually differentiated by a minor character. variety foveolate Having regular tiny pits. Compare . faveolate free Not united with other organs of the same type; not attached at one end. free central Of placentation, ovules attached to a free-standing column in the centre of a unilocular ovary. frond A of a leaf fern, cycad, or palm. frutescent -like ( Shrub ) or becoming shrub-like. fruticose fruticose Shrubby; having the branching character of a . shrub fruit A seed-bearing structure present in all , formed from the mature angiosperms and sometimes associated floral parts upon fertilization. ovary fugacious Disappearing, falling off, or withering. Compare and persistent . caducous funicle (funiculus) The stalk of an . ovule funnelform Having a form gradually widening from the base to apex; funnel-shaped. furcate Forked, usually applied to a terminal division; with two long lobes. fused Joined together. fusiform Rod-shaped and narrowing gradually from the middle toward each end; spindle-shaped. G
Longitudinal section of immature male pine cone, showing male
(pollen grains) developing between the cone scales
of a grass species with a fairly large inflorescence
Scanning electron micrograph of a
on the leaf of
. The two lip-shaped cells on either side of the pore are the
s guard cell
fluid on the
points fringing the immature leaf of a grapevine
LEFT 1- Welwitschia mirabilis 2- Cycas revoluta 3- Taxus baccata 4- Ginkgo biloba RIGHT 1- Cupressus sempervirens 2- Sequoiadendron giganteum 3- Agathis dammara 4- }} Araucaria heterophylla galbulus In , a fleshy cone ( gymnosperms ); chiefly relates to cones borne by megastrobilus junipers and cypresses, which are often mistakenly called . berries galea An overhanging, helmet-shaped, structure that protects the reproductive parts from precipitation, wind or unwanted visitors. gall Abnormal outgrowth on external plant tissues, caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. gamete A cell or nucleus that fuses with another of the opposite sex during sexual reproduction. gametophore Specialized structures on the of some gametophytes species, for example many species in the order bryophyte Marchantiales; in such species the gametes are produced on the gametophores, which amount to sex organs. gametophyte The haploid multicellular phase in the alternation of generations of plants and algae that bears . In gametes bryophytes the gametophyte is the dominant vegetative phase; in ferns and their allies it is a small free-living plant known as the prothallus; in gymnosperms and angiosperms the gametophytes are reduced to microscopic structures dependent on the , male gametophytes contained in sporophyte pollen grains and females contained within the ovules. gamopetalous with joined or fused petals gamophyllous a single perianth-whorl of united segments. Compare ( symphyllous synonym), , apophyllous polyphyllous gemma an asexual reproductive structure found in liverworts and mosses. gene pool The complete range of genetic variation found within a population. genus
A group of one or more
with features or ancestry (or both) in common. Genus is the principal category of taxa intermediate in rank between species and species in the standard nomenclatural hierarchy. family generic name The name of a taxonomic , such as genus and Acacia . Eucalyptus genotype The genetic make-up of an individual. geophilous Growing or rooting in the ground. germination 1. of seeds, describing the complex sequence of physiological and structural changes that occur from resting to growth stage. 2. of a pollen grain; production of a pollen tube when contacting a stigma receptive to it. 3. of a spore of fungi/bacterium; change of state – from resting to vegetative. gibbous (gibbose) (of part of an organ) Swollen, usually with a pouch-like enlargement at the base. glabrescent Becoming , almost glabrous; glabrate. glabrous glabrous 1. Lacking surface ornamentation such as hairs, scales or bristles; smooth. 2. In lichenology, having no . indumentum gland A secretory structure within or on the surface of a plant. glandular hair A hair tipped with a gland. glaucous Describes the external surface of a plant part that has a whitish covering, in some cases with a blueish cast. Often applied to plants with a woolly or surface, but properly referring to arachnoid surfaces, meaning those with a waxy pruinose . The surface of the young leaves of many bloom eucalypts provide good examples, and so do some s. xerophyte globose
Roughly spherical. See also
. subglobose globulose Approximately spherical. glochid A tiny barbed hair or bristle, e.g. the fine defensive hairs in cactus species such as . Opuntia glumes subtending the floret(s) of a bracts sedge, or similar plant; in grasses forming the lowermost organs of a (there are usually 2 but 1 is sometimes reduced; or rarely, both are absent). spikelet glutinous Sticky. graft 1. The artificial union of plant parts. 2. A plant suitable for grafting; loosely, a shoot , scion , or branch. sucker graft chimaera (sometimes graft hybrid) A taxon whose members consist of tissue from two or more different plants in intimate association originated by grafting. The addition sign "+" is used to indicate a graft-chimaera either as a part of a formula (e.g. + Crataegus monogyna ) or in front of an abbreviated name (e.g. Mespilus germanica + 'Dardari'). The nomenclature of graft hybrids is governed by the Crataegomespilus International Code of Nomenclature for Cultivated Plants. graminoid granular (of a surface) Covered with small rounded protuberances. grass A plant of the family Poaceae. grassland Low vegetation dominated by grasses. groundcover 1. Dense vegetation that covers the ground. 2. A term applied to describe a plant that covers the soil surface so densely that it smothers all beneath it. group A formal category equivalent to or below the rank of which distinguishes: genus an assemblage of two or more cultivars within a species or hybrid; plants derived from a hybrid in which one or more of the parent species is not known or is of uncertain origin; a range of cultivated plants of a species or hybrid which may exhibit variation but share one or more characters, which makes it worth distinguishing them as a unit. guard cell Each of two cells surrounding the which control gas exchange between the stoma of the plant and the external environment. apoplast guttate Having droplet-shaped spots. Compare and punctate . maculate guttation The secretion of liquid water from uninjured plant parts. See . hydathode guttulate Having or appearing to be spotted with oil droplets; of spores, having oil droplets inside. gymnosperm A seed-bearing plant with unenclosed ovules borne on the surface of a . Gymnosperms are among the oldest clades of vascular plants, and today are represented by approximately 1,000 extant species worldwide, including, among others, sporophyll conifers, , Ginkgo and Gnetum cycads. Compare . angiosperm gynobasic Of a style, arising near the base of the , e.g. between the lobes of the gynoecium . ovary gynodioecious Of a species, with some plants bearing only flowers and others bearing only female flowers. bisexual gynomonoecious Of a species, with flowers and female flowers on the same plant. bisexual gynoecium The collective term for the female reproductive parts of a flower or for the of a flower, whether united or free. Contrast carpels . Abbreviation: androecium G. For instance, indicates a G ; G(5) indicates having five fused carpels. superior ovary gynophore A stalk supporting the and situated above the level of gynoecium of the other floral parts. insertion gynostegium A compound organ in milkweeds ( Asclepiadaceae) and orchids formed by fusion of the of the filaments with the stamens . Also known as the style