The Families of Flowering Plants
The Families of Flowering Plants | |
~ Rubiaceae
Habit and leaf form. Small or medium trees. Leaves alternate, or whorled; simple. Lamina entire. Leaves stipulate. Stipules without colleters. Lamina margins entire.
General anatomy. Plants with ‘crystal sand’.
Leaf anatomy. Lamina dorsiventral.
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Primary medullary rays narrow. Wood parenchyma mainly paratracheal (aliform to confluent).
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles (thyrses). The ultimate inflorescence unit cymose. Inflorescences terminal; terminal thyrses. Flowers large; very irregular; zygomorphic; cyclic; tetracyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 9–10; 2 whorled; isomerous, or anisomerous. Calyx 4–5; 1 whorled; polysepalous (?); not persistent. Corolla 5; 1 whorled; gamopetalous; imbricate; campanulate; bilabiate.
Androecium 5. Androecial members adnate (epipetalous); markedly unequal (the filaments curved); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous; alternating with the corolla members; filantherous (the filaments bent at the base). Anthers dorsifixed (the base sagittate); dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 5–6 aperturate; colpate.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; synstylovarious; inferior. Ovary 2 locular. Epigynous disk present (annular). Gynoecium stylate. Styles 1; apical. Stigmas 2. Placentation axile. Ovules 2–4 per locule; collateral.
Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (semi-superior or almost superior, transversely ovoid, subreniform or discoid). Fruit 2–4 seeded. Seeds non-endospermic; wingless (but flattened).
Geography, cytology. Neotropical. Tropical. Brazil.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Lamiiflorae; Scrophulariales. Cronquist’s Subclass Asteridae; Rubiales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Gentianales (as a synonym of Rubiaceae).
Species 13. Genera 2; Henriquezia, Platycarpum.
This description is inadequate.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 4th March 2011. http://delta-intkey.com’.