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An order of the true mosses (subclass Bryidae). This order is difficult to define precisely, but includes plants that generally grow from a creeping primary stem with leaves reduced or essentially lacking and plants that have spreading to ascending…

An order in the class Lycopsida that diverged from the Lepidodendrales in the Late Devonian. These two groups have several characters that are not found in other lycopsids, notably a centralized, shootlike rooting structure (rhizomorph) that allows…

A shrub, Simmondsia chinensis, adapted to the arid portions of the southwestern United States and Mexico, and cultivated for a liquid wax that is extracted from its seed. Jojoba is a broadleaf evergreen shrub (see illustration) that is typically 1–3…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Hamamelidae of the class Magnoliopsida (dicotyledons). The order consists of two families: the Juglandaceae with a little over 50 species and the Rhoipteleaceae…

The largest order of liverworts, often called the leafy liverworts; it consists of 43 families. The leaves are in three rows, with the underleaves usually reduced or lacking. Other distinctive features include a perianth formed by a fusion of…

One of the two subclasses of liverworts (class Hepaticopsida). The plants may be thallose, with little or no tissue differentiation, or they may be organized into erect or prostrate stems with leafy appendages. The leaves, generally one cell in…

A natural fiber obtained from two Asiatic species, Corchorus capsularis and C. olitorius (which are also termed jute), of the plant family Malvaceae (alternatively Tiliaceae). Jute plants (see illustration) are tall, slender, half-shrubby annuals…

An annual, short-day, herbaceous plant, Hibiscus cannabinus (of the Malvaceae family), which is cultivated for its stem fibers. Kenaf (see illustration) usually grows upright, reaching 4.5 m (15 ft) in height, and is cylindrical and either branched…

A large, strikingly distinct tree, Gymnocladus dioica. The Kentucky coffee tree usually grows to a height of 80–90 ft (24–27 m), but sometimes attains a height of 110 ft (33 m) and a diameter of 5 ft (1.5 m). The species name, dioica, means that the…

A vigorous deciduous fruiting vine (family Actinidiaceae), and the name of the fruit itself, that is native to central China, where it commonly grows in moist and sheltered areas on the forest edges. Kiwifruit (Fig. 1), which belongs to the plant…

A mold that is one of the most widely used fungi in industry. Especially with regard to the Japanese way of life, Aspergillus oryzae, a type of koji mold (Fig. 1), is quite indispensable, being an essential substance of traditional foods and…

An order of flowering plants (Magnoliophyta, or angiosperms), in the subclass Asteridae (Eudicotyledons). The order consists of some 22 families with approximately 1100 genera and over 21,000 species. Seven families (Acanthaceae, Gesneriaceae,…

An order of large brown algae (class Phaeophyceae) commonly called kelps. Definitive features of members of the Laminariales include a life history in which microscopic, filamentous, dioecious gametophytes alternate with a massive, parenchymatous…

A genus, Larix, of the pine family, with deciduous needles and short spurlike branches, which annually bear a crown of needles. The cones of the larch tree (see illustration) are small and persistent, varying by species in size, number, and form of…

Strips or cylinders of dividing cells located parallel to the long axis of the organ in which they occur. Radial enlargement of the cells derived from these meristems increases the diameter of the organ. The lateral meristem is concerned with…

An order of flowering plants composed of seven eumagnoliid families of tropical tree species that are important ecologically; some are shrubs. They include in total about 2500 species. They are most closely related to Magnoliales, from which they…

A lateral appendage which is borne on a plant stem at a node (joint) and which usually has a bud in its axil. In most plants, leaves are flattened in form, although they may be nearly cylindrical with a sheathing base as in onion. Leaves usually…

A method, developed originally by A. M. Legendre, of obtaining the best values (the ones with least error) of unknown quantities supposed to satisfy a system of linear equations of the form shown as notation (1),1where n > m. Since there are more…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Dilleniidae of the class Magnoliopsida (dicotyledons). The order consists of the single family Lecythidaceae, with about 400 species. They are tropical, woody…

Solutions to the differential equation (1 − x2)y′ − 2xy′ + v(v + 1)y = 0. Legendre polynomials The most elementary of the Legendre functions, the Legendre polynomial Pn(x) can be defined by the generating function in Eq. (1). More explicit…

An order of flowering plants, division Magnoliophyta (Angiospermae) in the subclass Hamamelidae of the class Magnoliopsida (dicotyledons). The order consists of a single family, genus, and species (Leitneria floridana) of the southeastern United…

A curve shaped like the figure eight (see illustration), referred to by Jacques Bernoulli in 1694. Let F1, F2 be points of a plane π, with F1 F2 = 2a, a > 0. The locus of a point P of π which moves so that PF1 · PF2 = b2, where b is a positive…

Citrus limon, a small evergreen tree belonging to the order Sapindales that is cultivated for its fruit. The lemon is commercially the most important of the acid citrus fruits. It probably originated in the eastern Himalayan region of India, or…

An extinct order of the class Lycopsida which, together with Isoetales, forms the monophyletic rhizomorphaleans, the most derived and diverse group of clubmosses. The lepidodendraleans are best known as the scale trees that dominate most…

A cool-season annual, Lactuca sativa, of Asian origin and belonging to the tribe Cichorium of the Compositae family. Lettuce (see illustration) is grown for its succulent leaves, which are eaten raw as a salad. Four varieties of this leading salad…