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RUBIACEAE
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RUBIACEAE , in See also:botany, a large natural See also:order of See also:seed See also:plants, belonging to the See also:series Rubiales of the subclass Sympetalae (Gamopetalae) of See also:Dicotyledons, and containing about 350 genera with about 4500 See also:species. It is mainly a tropical See also:family of trees, shrubs and herbs, but some of the tribes, especially Galieae, to which the See also:British representatives belong and which contains only herbs, are more strongly See also:developed in temperate regions;. some species of Galium reach the See also:Arctic See also:zone and are found at high elevations on mountains in the tropics. The most striking characteristic of the family are the opposite-decussate, generally entire, stipulate leaves. The stipules are very varied in See also:form; they generally stand between the petioles of a pair of leaves (interpetiolar). The two stipules of adjacent leaves are usually See also:united, and in the Galieae, as well shown in the British species, are enlarged and See also:leaf-like, forming with the two leaves an apparent whorl; by See also:fusion or branching of the stipules the number of leaves in the whorl varies from four to eight or more. The See also:flowers are rarely solitary, terminal or axillary, as in See also:Gardenia; generally they are arranged in cymes or panicles or crowded into heads, and are often showy; in British members of the family they are very small, but may be conspicuous from their See also:numbers, as in See also:lady's bedstraw (Galium verum). The flowers are hermaphrodite and See also:regular with parts in fours or See also:fives; the four or five sepals, petals and stamens are placed above the ovary, which consists of two carpels, contains one to indefinite anatropous ovules in each of the two See also:chambers, and is crowned by a See also:simple See also:style ending in a See also:head or in two lobes. The sepals are often small, sometimes reduced to a narrow See also:ring encircling the See also:top of the ovary or altogether absent. The united petals form a corolla which varies widely in form in the different genera; it is often See also:funnel- or See also:salver-shaped, the See also:honey, which is secreted by a disk See also:round the See also:base of the style, being at the bottom of a longer or shorter See also:tube, in which See also:case the flowers are adapted for See also:pollination by See also:Lepidoptera or bees, as in Gardenia, Mussaenda, Guettarda, &c.; in other cases it is See also:bell-shaped or, as in Galium, rotate, with a See also:short tube and sharply spreading segments; the honey is in these cases freely exposed or only slightly concealed and the flowers are pollinated by flies. The stamens are attached to the corolla-tube and alternate in position with its segments; the flowers are often dimorphic (or heterostyled) with short-styled and See also:long-styled forms as in See also:ipecacuanha (see fig.). The See also:fruit also varies widely in form and is dry or fleshy. When dry it forms a See also:capsule with septicidal or loculicidal dehiscence, or is a schizocarp separating when dry into two one-seeded mericarps which, as in the British See also:cleavers (Galium Aparine), sometimes See also:bear hooked appendages which aid their dispersal. Some genera show a remarkable association with ants. Thus Myrmecodia, Hydnophytum are epiphytic plants, in which the base of the See also:stem forms a large tuber, which is attached to the support by numerous See also:adventitious roots. The substance of the tuber is penetrated by numerous See also:cork-lined cavities communicating by galleries, which are inhabited by ants. There is no See also:evidence that the presence of the ants is of any service to the plant. The order is divided into a large number of tribes based on the number of ovules in each ovary-chamber, the See also:character of the fruit seed and ovule, and the See also:aestivation of the corolla. These may be arranged in three families as follows: Cinchoneae, often woody plants with See also:scale-like stipules, and numerous ovules in each ovary-chamber; the fruit is generally a capsule. To this belong See also:Cinchona (q.v.), a genus of large trees with handsome flowers containing about See also:forty species in the See also:Andes of See also:South See also:America—it is well known as the source of Peruvian bark. An allied genus, See also:Bouvardia (q.v.), from tropical America, is cultivated for its flowers. The species of Uncaria climb by means of hooks which are modified inflorescence-axes. Mussaenda, Gardenia (q.v.), and other genera are characterized by having a fleshy fruit. Coffeeae, often woody or shrubby plants with scale-like stipules; each ovary-chamber contains only one ovule. See also:Coffee (q.v.), a genus of shrubs with about twenty-five species in the Old See also:World tropics, includes the coffee plant (C. arabica and C. liberica) ; the fruit is a two-seeded drupe, the seed is the " coffee-See also:bean." The thickened See also:root of Uragoga ipecacuanha yields ipecacuanha (q.v.). Stellateae, herbaceous plants with leaf-like stipules; each ovary-chamber contains one ovule only. Includes the four British genera Rubia, one species of which, R. tinctorum, is See also:madder; Galium, including G. verum (lady's bedstraw), G. A parine (See also:goose-grass orcleavers), and other British species; Asperula, including A. odorata (woodruff) and Sherardia. The order is closely allied to See also:Caprifoliaceae, the See also:chief distinction being the See also:absence of stipules in the latter. , ),1 Ipecacuanha Plant. Additional information and CommentsThere are no comments yet for this article.
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