Raceme

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The inflorescence of Vanda garayi, an epiphytic orchid, is a typical raceme. Vanda garayi.png
The inflorescence of Vanda garayi , an epiphytic orchid, is a typical raceme.

A raceme ( /rˈsm/ or /rəˈsm/ ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the shoot grows in height, with no predetermined growth limit. Examples of racemes occur on mustard (genus Brassica ) and radish (genus Raphanus ) plants.

Contents

Definition

A raceme or racemoid is an unbranched, indeterminate type of inflorescence bearing pedicellate flowers (flowers having short floral stalks called pedicels ) along its axis. [1] In botany, an axis means a shoot, in this case one bearing the flowers. In indeterminate inflorescence-like racemes, the oldest flowers grow close to the base and new flowers are produced as the shoot grows in height, with no predetermined growth limit. [2] A plant that flowers on a showy raceme may have this reflected in its scientific name, e.g. the species Cimicifuga racemosa . A compound raceme, also called a panicle , has a branching main axis. Examples of racemes occur on mustard (genus Brassica ) and radish (genus Raphanus ) plants. [3]

Spike

A spike is an unbranched, indeterminate inflorescence, similar to a raceme, but bearing sessile flowers (sessile flowers are attached directly, without stalks). [2] Examples occur on Malabar nut ( Justicia adhatoda ) and chaff flowers (genus Achyranthes ). [3] A spikelet can refer to a small spike, although it primarily refers to the ultimate flower cluster unit in grasses (family Poaceae) and sedges (family Cyperaceae), [2] in which case the stalk supporting the cluster becomes the pedicel. A true spikelet comprises one or more florets enclosed by two glumes (sterile bracts), with flowers and glumes arranged in two opposite rows along the spikelet. Examples occur on rice (species Oryza sativa ) and wheat (genus Triticum ), both grasses. [3]

Catkin

An ament or catkin is very similar to a spike or raceme "but with subtending bracts so conspicuous as to conceal the flowers until pollination, as in the pussy–willow, alder, [and] birch...". These are sometimes called amentaceous plants. [4]

Spadix

A spadix is a form of spike in which the florets are densely crowded along a fleshy axis and enclosed by one or more large, brightly–colored bracts called spathes . Usually the female flowers grow at the base, and male flowers grow above. [3] They are a characteristic of the family Araceae, for example jack–in–the–pulpit (species Arisaema triphyllum ) and wild calla (genus Calla ). [4]

Examples

Etymology

From classical Latin, a racemus is a cluster of grapes. [5]

See also

Related Research Articles

<i>Amorphophallus</i> Genus of flowering plants

Amorphophallus is a large genus of some 200 tropical and subtropical tuberous herbaceous plants from the Arum family (Araceae), native to Asia, Africa, Australia and various oceanic islands. A few species are edible as "famine foods" after careful preparation to remove irritating chemicals. The genus includes the Titan arum of Indonesia, which has the largest inflorescence of any plant in the genus, and is also known as the 'corpse flower' for the pungent odour it produces during its flowering period, which can take up through seven years of growth before it occurs.

<span class="mw-page-title-main">Inflorescence</span> Term used in botany to describe a cluster of flowers

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. One can also define an inflorescence as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern.

Panicle Term used in botany to describe a branching of flower heads

A panicle is a much-branched inflorescence. Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers be pedicellate. The branches of a panicle are often racemes. A panicle may have determinate or indeterminate growth.

<span class="mw-page-title-main">Spadix (botany)</span>

In botany, a spadix is a type of inflorescence having small flowers borne on a fleshy stem. Spadices are typical of the family Araceae, the arums or aroids. The spadix is typically surrounded by a leaf-like curved bract known as a spathe. For example, the "flower" of the well known Anthurium spp. is a typical spadix with a large colorful spathe.

<span class="mw-page-title-main">Bract</span> Modified or specialized leaf

In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals. A plant having bracts is referred to as bracteate or bracteolate, while one that lacks them is referred to as ebracteate and ebracteolate, without bracts.

<i>Andropogon gerardi</i> Species of grass

Andropogon gerardi, commonly known as big bluestem, is a species of tall grass native to much of the Great Plains and grassland regions of central and eastern North America. It is also known as tall bluestem, bluejoint, and turkeyfoot.

<span class="mw-page-title-main">Indeterminate growth</span>

In biology and botany, indeterminate growth is growth that is not terminated in contrast to determinate growth that stops once a genetically pre-determined structure has completely formed. Thus, a plant that grows and produces flowers and fruit until killed by frost or some other external factor is called indeterminate. For example, the term is applied to tomato varieties that grow in a rather gangly fashion, producing fruit throughout the growing season, and in contrast to a determinate tomato plant, which grows in a more bushy shape and is most productive for a single, larger harvest, then either tapers off with minimal new growth or fruit, or dies.

<i>Bouteloua curtipendula</i> Species of flowering plant

Bouteloua curtipendula, commonly known as sideoats grama, is a perennial, short prairie grass that is native throughout the temperate and tropical Western Hemisphere, from Canada south to Argentina.

<span class="mw-page-title-main">Spikelet</span> Part of a spike inflorescence of a grass or sedge

A spikelet, in botany, describes the typical arrangement of the flowers of grasses, sedges and some other Monocots.

This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.

<i>Bromus secalinus</i> Species of grass

Bromus secalinus is a species of bromegrass known as rye brome. The specific epithet secalinus is Latin, meaning "rye-like". The fruits are hard, rounded glumes that appear superficially similar to the rye grain, which gives the brome its common and scientific name. The grass has a diploid number of 28.

This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology. For other related terms, see Glossary of phytopathology and List of Latin and Greek words commonly used in systematic names.

<i>Redfieldia</i> Genus of grasses

Redfieldia, known as blowout grass, is a monotypic genus in the grass family (Poaceae). The sole species, Redfieldia flexuosa, is native to sandhills in the western and central United States. The plants grow in small clusters, protecting each other from the harsh desert conditions.

<i>Corymbium</i> Genus of perennial plants in the family Asteraceae from South Africa

Corymbium is a genus of flowering plants in the daisy family comprising nine species. It is the only genus in the subfamily Corymbioideae and the tribe Corymbieae. The species have leaves with parallel veins, strongly reminiscent of monocots, in a rosette and compounded inflorescences may be compact or loosely composed racemes, panicles or corymbs. Remarkable for species in the daisy family, each flower head contains just one, bisexual, mauve, pink or white disc floret within a sheath consisting of just two large involucral bracts. The species are all endemic to the Cape Floristic Region of South Africa, where they are known as plampers.

<i>Oplismenus compositus</i> Species of flowering plant

Oplismenus compositus, the running mountaingrass, is a species of perennial plant from the family Poaceae that can be found throughout Asia, Africa, Australia, South America, Mexico and Hawaii.

Oplismenus thwaitesii is a flowering plant that is endemic to India.

Festuca polycolea is a species of grass which is endemic to India.

<i>Ischaemum rugosum</i> Species of grass

Ischaemum rugosum, also known as saramollagrass, is a flowering plant belonging to the grass family Poaceae in the genus Ischaemum, and is native to tropical and temperate regions of Asia, growing in marshes and other wet habitats. It is a vigorous annual, and is an invasive species in South America and Madagascar. It reaches heights of up to 1 m and is primarily recognized by the ridged surface of its sessile spikelet’s lower glume. Despite its historic importance as fodder in Asia, the grass has become a major weed in mid-latitude rice paddies throughout Asia and South America.

<i>Rottboellia cochinchinensis</i> Species of grass

Rottboellia cochinchinensis is a species of grass known by the common names Itchgrass,Raoul grass, corngrass, Kokoma grass, Guinea-fowl grass, jointed grass, Shamwa grass and Kelly grass. It is a tall, tufted annual grass whose stems (culms) grow up to 3 metres in height with leaf-blades of up to 45 centimetres in length. The species flowers at the apex of culms in the form of spike-like racemes composed of paired spikelets. The common name Itchgrass comes from the bristly (hispid) leaf-sheath which can be irritating to the skin.

Salix dissa is a low shrub from the genus willow (Salix) with usually 1 to 3 centimeters long leaf blades. The natural range of the species is in China.

References

  1. Walters, Dirk R.; Keil, David J. (1 January 1996). Vascular Plant Taxonomy (4th ed.). United States: Kendall/Hunt Publishing Company. p.  602. ISBN   978-0-7872-2108-9.
  2. 1 2 3 Wofford, B. Eugene (1989). Guide to the Vascular Plants of the Blue Ridge. University of Georgia Press. pp. 10–15. ISBN   978-0-8203-2455-5.
  3. 1 2 3 4 Kumar, Vinay; Bhatia, S. S. (2013). Complete Biology for Medical College Entrance Examination. McGraw Hill Education Series (3rd ed.). McGraw Hill Education (India) Private Limited. p. 218. ISBN   978-1-259-06430-2.
  4. 1 2 Gilman, Daniel Coit., ed. (1907). The new international encyclopædia. Vol. 10. Peck, Harry Thurston; Colby, Frank Moore. New York: Dodd, Mead and Company. p. 618.
  5. Oxford English Dictionary. Raceme 2. Bot. A type of inflorescence in which the flowers are arranged on short, nearly equal, lateral pedicels, at equal distances along a single elongated axis