Plant cells are the cells present in green plants, photosynthetic eukaryotes of the kingdom Plantae. Their distinctive features include primary cell walls containing cellulose, hemicelluloses and pectin, the presence of plastids with the capability to perform photosynthesis and store starch, a large vacuole that regulates turgor pressure, the absence of flagella or centrioles, except in the gametes, and a unique method of cell division involving the formation of a cell plate or phragmoplast that separates the new daughter cells.
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word xylem is derived from the Ancient Greek word ξύλον (xylon), meaning "wood"; the best-known xylem tissue is wood, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858.
In biology, tissue is a historically derived biological organizational level between cells and a complete organ. A tissue is therefore often thought of as an assembly of similar cells and their extracellular matrix from the same embryonic origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
Salvia spathacea, the California hummingbird sage or pitcher sage, is a species of flowering plant in the family Lamiaceae, native to southern and central California growing from sea level to 610 m (2,001 ft). This fruity scented sage blooms in March to May with typically dark rose-lilac colored flowers. It is cultivated in gardens for its attractive flowering spikes and pleasant scent.
The ground tissue of plants includes all tissues that are neither dermal nor vascular. It can be divided into three types based on the nature of the cell walls. This tissue system is present between the dermal tissue and forms the main bulk of the plant body.
- Parenchyma cells have thin primary walls and usually remain alive after they become mature. Parenchyma forms the "filler" tissue in the soft parts of plants, and is usually present in cortex, pericycle, pith, and medullary rays in primary stem and root.
- Collenchyma cells have thin primary walls with some areas of secondary thickening. Collenchyma provides extra mechanical and structural support, particularly in regions of new growth.
- Sclerenchyma cells have thick lignified secondary walls and often die when mature. Sclerenchyma provides the main structural support to a plant.
The epidermis is a single layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. The epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds, and absorbs water and mineral nutrients. The epidermis of most leaves shows dorsoventral anatomy: the upper (adaxial) and lower (abaxial) surfaces have somewhat different construction and may serve different functions. Woody stems and some other stem structures such as potato tubers produce a secondary covering called the periderm that replaces the epidermis as the protective covering.
Ajuga reptans is commonly known as bugle, blue bugle, bugleherb, bugleweed, carpetweed, carpet bugleweed, and common bugle, and traditionally however less commonly as St. Lawrence plant. It is an herbaceous flowering plant in the mint family Lamiaceae, native to Europe. It is invasive in parts of North America. It is also a component of purple moor grass and rush pastures, a Biodiversity Action Plan habitat in the United Kingdom.
Lamium amplexicaule, commonly known as common henbit, or greater henbit, is a species of Lamium native to Europe, Asia and northern Africa.
Ballota nigra, black horehound, is a perennial herb of the family Lamiaceae. It is native to the Mediterranean region and to central Asia and it can be found throughout Europe. It is also naturalized in Argentina, New Zealand, and the Eastern United States. It blooms in the Northern Hemisphere from May to August.
Downingia bella, also known as Hoover's calicoflower or Hoover's Downingia, is a member of the Bellflower Family (Campanulaceae). The genus is named after A.J. Downing (1815–1852) a noted American horticulturist and landscape architect.
Salvia pratensis, the meadow clary or meadow sage, is a species of flowering plant in the family Lamiaceae, native to Europe, western Asia and northern Africa. The Latin specific epithet pratensis means "of meadows", referring to its preferred habitat. It also grows in scrub edges and woodland borders.
Stachys byzantina, the lamb's-ear or woolly hedgenettle, is a species of flowering plant in the mint family Lamiaceae, native to Armenia, Iran, and Turkey. It is cultivated over much of the temperate world as an ornamental plant, and is naturalised in some locations as an escapee from gardens. Plants are very often found under the synonym Stachys lanata or Stachys olympica.
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.
Lepidodendrales or arborescent lycophytes are an extinct group of primitive, vascular, heterosporous, arborescent (tree-like) plants belonging to Lycopodiopsida. Members of Lepidodendrales are the best understood of the fossil lycopsids due to the vast diversity of Lepidodendrales specimens and the diversity in which they were preserved; the extensive distribution of Lepidodendrales specimens as well as their well-preservedness lends paleobotanists exceptionally detailed knowledge of the coal-swamp giants’ reproductive biology, vegetative development, and role in their paleoecosystem. The defining characteristics of the Lepidodendrales are their secondary xylem, extensive periderm development, three-zoned cortex, rootlike appendages known as stigmarian rootlets arranged in a spiralling pattern, and megasporangium each containing a single functional megaspore that germinates inside the sporangium. Many of these different plant organs have been assigned both generic and specific names as relatively few have been found organically attached to each other. Some specimens have been discovered which indicate heights of 40 and even 50 meters and diameters of over 2 meters at the base. The massive trunks of some species branched profusely, producing large crowns of leafy twigs; though some leaves were up to 1 meter long, most were much shorter, and when leaves dropped from branches their conspicuous leaf bases remained on the surface of branches. Strobili could be found at the tips of distal branches or in an area at the top of the main trunk. The underground organs of Lepidodendrales typically consisted of dichotomizing axes bearing helically arranged, lateral appendages serving an equivalent function to roots. Sometimes called "giant club mosses", they are believed to be more closely related to extant quillworts based on xylem, although fossil specimens of extinct Selaginellales from the Late Carboniferous also had secondary xylem.
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.
Mimulus alatus, the sharpwing monkeyflower, is an herbaceous eudicot perennial that has no floral scent. It is native to North America and its blooming season is from June to September. The flowering plant has green foliage and blue to violet flowers. It has a short life span compared to most other plants and a rapid growth rate. Like other monkey-flowers of the genus Mimulus, M. alatus grows best in wet to moist conditions and has a bilabiate corolla, meaning it is two-lipped. The arrangement of the upper and lower lip petals suggests a monkey’s face. The winged stems together with the monkey face give the plant its common name.
Famatinanthus is a genus in the family Asteraceae that was described in 2014 and has been assigned to its own tribe Famatinantheae and subfamily Famatinanthoideae. It contains only one known species, F. decussatus, a small shrub of ½—1¾ m high that is an endemic of the Andes of north-western Argentina, with small, entire, oppositely set leaves and flowerheads containing about ten cream-colored, ray and disk florets, with backward coiled lobes. It is locally known as sacansa. For more than 100 years, the species was known to science only from the type collection. It was described in 1885 and originally assigned to the genus Aphyllocladus.
Hypericum sechmenii, or Seçmen's St John's wort, is a rare species of flowering plant of the St John's wort family (Hypericaceae) that is found only in the Eskişehir Province of central Turkey. Its appearance and characteristics were first described in 2009 by Turkish botanists Atila Ocak and Onur Koyuncu, who named the species in honor of Özcan Seçmen, a fellow botanist. After this description, the species was incorporated into the organization of the genus Hypericum by Norman Robson, who placed H. sechmenii into section Adenosepalum. It is a perennial herb which grows in clusters of stems 3–6 centimetres (cm) tall and blooms in June and July. The stems of the plant are smooth and lack hairs, while the leaves are leathery and do not have leafstalks. Its flowers are arranged in clusters that form a flat-topped shape known as a corymb, and each flower possesses five bright yellow petals. There are several species that are similar in appearance to H. sechmenii, with only minor physical differences that set them apart. The most closely related of these are Hypericum huber-morathii, H. minutum, and H. thymopsis.
Plectranthus purpuratus or cliff spurflower is a species of flowering plant in the family Lamiaceae, native to South Africa's Kwazulu-Natal and Mpumalanga provinces, as well as eSwatini. The name is frequently misapplied to Plectranthus ciliatus, presumably because both have purple-backed leaves.
Stachys stebbinsii is a species of perennial herb in the mint family commonly known as Stebbins' hedgenettle. This plant is characterized by a musky aroma, flowers with large lower lips, and glandular hairs that densely cover the stems. S. stebbinsii is native to California and northwestern Baja California. It is usually found growing in moist places in a wide variety of habitats including disturbed areas, chaparral, coastal sage scrub and mountains.
