Perennial or annual herbs, often more or less succulent, mostly terrestrial, sometimes aquatic, frequently producing adventitious roots at the nodes; stems erect to prostrate, rarely somewhat climbing. Leaves alternate (falsely whorled in Palisota), with a basal membranous often nervose and closed sheath. Inflorescence composed of single or aggregated cincinni, terminal, lateral or axillary; sometimes each cincinnus may be reduced to single or (apparently) fascicled flowers. Flowers actinomorphic or zygomorphic, often surrounded by mucilage. Sepals 3, free, usually green or membranous. Petals 3 (one often smaller than the other 2), white or coloured, free or sometimes united below into a tube. Stamens hypogynous, basically 6 in two whorls, but variously modified or suppressed; fertile stamens 2, 3 or 6; staminodes 0, 3 (or rarely 4); filaments (with us) free, glabrous or with moniliform hairs; anthers dorsifixed or basifixed, 2-locular, dehiscing by longitudinal slits (or by basal pores in Cyanotis). Ovary superior, 2-3-locular, with a simple terminal style and a small more or less capitate stigma; ovules 1-6 (-10) per loculus, axile. Fruit usually a loculicidal capsule, sometimes partly or wholly indehiscent, or (in Palisota) a berry. Seeds usually crowded, with the contiguous faces flat, often muricate, ridged or reticulate, relatively large; the testa characteristically marked on the outside with a circular or elliptic callosity called the embryostega (or embryotega), under which the embryo is situated; hilum punctiform or linear; endosperm abundant, mealy.
Notes: The leading features of the family are the leaf-sheaths, the inflorescence of cincinni, the separate calyx and corolla, and the embryostega on the seed. According to Mr. D. P. Stanfield, to whose observations on the family as a whole this account owes much, the family is "readily recognized by the involute margins of the young leaves, a characteristic feature of all the genera in West Tropical Africa except Cyanotis".The frail flowers are usually fully open for a short time only—sometimes for but a few hours during the day—and closely related species may differ in the times at which their flowers are expanded.
Perennial or occasionally annual, terrestrial, or rarely epiphytic, monoecious, or andromonoecious, rarely polygamomonoecious, small to large herbs, with erect to ascending, diffusely spreading or stoloniferous, occasionally rhizomatous, rarely scandent shoots, decumbent in Plowmanianthus. Roots fibrous or tuberous. Leaves sheathing the stem at the base, alternate or in pseudowhorls, spirally arranged or distichous, sheaths closed, eligulate; lamina simple, entire, often narrowed into a false petiole, petiolate in Plowmanianthus, commonly somewhat succulent, ptyxis involute, less commonly convolute or supervolute. Inflorescences terminal or terminal and axillary, in some genera all axillary and perforating the sheaths, commonly a paniclelike thyrse composed of several to many helicoid, cymose branches (cincinni), sometimes reduced to a single cincinnus or, rarely, to a single flower, sometimes enclosed in or closely subtended by a leafy bract (spathe). Flowers actinomorphic or zygomorphic, usually bisexual or bisexual and male, rarely female and bisexual or female, bisexual and male, remaining open for only a few hours, then deliquescing. Nectaries lacking. Calyx composed of 3, equal or unequal, free or partly fused, sepaline or petaline sepals. Corolla composed of 3, equal to dimorphic, free or basally fused, white or colared petals. Androecium composed of 6 stamens arranged in 2 whorls, sometimes all fertile and equal or unequal, often 2-3(-4) reduced to staminodes, occasionally 1-3 (rarely all) lacking, staminodes either alternating with the stamens or else arranged on one side of the flower and the stamens on the other, filaments glabrous or some or all bearded, anthers dehiscing longitudinally, rarely poricidally, sometimes lacking (Plowmanianthus). Ovary superior, bi- or trilocular, locules equal or dorsallocule reduced, ovules uniseriate or biseriate, or partly biseriate, 1-many per locule, sometimes sessile and densely pubescent. Style terminal on ovary, simple, usually slender, stigma terminal, simple, small, or enlarged, or annular and papillate (Plowmanianthus). Fruit a dehiscent or rarely indehiscent capsule, berry-like indehiscent capsule, or berry. Seeds with an embryotega or operculum covering the embryo, hilum dorsal, lateral, semilateral, or terminal.
Commelinaceae are ecologically diverse. They are found chiefly in humid and mesic habitats, such as forest and grassland. Within the tropics, where they grow from sea level to 3800 m, species occur in all but the most xeric and most saline habitats. Few Commelinaceae are aquatics except for species of Floscopa.
The General Description is derived from the account of Commelinaceae in Kubitzki volume 4 with additions from the later described genus Plowmanianthus. With kind permission from Springer Science+Business Media: This work is subject to copyright. All rights reserved, whether whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, broadcasting reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under German Copyright Law.All Rights Reserved
With kind permission from Springer Science+Business Media: This work is subject to copyright. All rights reserved, whether whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, broadcasting reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under German Copyright Law.All Rights Reserved