The Families of Flowering Plants
The Families of Flowering Plants | |
~ Iridaceae
Habit and leaf form. Small, colourless herbs (lacking rhizomes and corms, the scaly, basal part of the stem with mycorrhizal roots). Plants saprophytic. Leaves small (reduced); alternate; membranous; simple. Lamina entire. Lamina margins entire.
Stem anatomy. Secondary thickening presumably absent.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The ultimate inflorescence unit cymose. Flowers bracteate; small; regular; cyclic; tetracyclic. Perigone tube present (short).
Perianth of ‘tepals’; 6; joined; 2 whorled (3+3, the outer imbricate, the inner contorted); isomerous; petaloid; similar in the two whorls; blue (-ish).
Androecium 3. Androecial members adnate (to the base of the perianth); all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 3; isomerous with the perianth; alterniperianthial (opposite the outer perianth segments); very shortly filantherous. Anthers basifixed (oblong); non-versatile; dehiscing via longitudinal slits; extrorse; tetrasporangiate. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate (sulcoidate).
Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil 3 celled. Gynoecium syncarpous; synstylovarious, or eu-syncarpous (?); inferior. Ovary 3 locular. Epigynous disk absent. Gynoecium stylate. Styles 1 (tribrachiate); apical. Stigmas 3. Placentation axile (the placentas branched, intruding).
Fruit non-fleshy; dehiscent, or indehiscent (?); a capsule, or capsular-indehiscent (?—with an annulus which may be marcescent). Capsules circumscissile (triangular-obconical). Seeds minute. Testa without phytomelan (?).
Geography, cytology. Paleotropical. Tropical. Madagascar.
Taxonomy. Subclass Monocotyledonae. Superorder Liliiflorae; Liliales (cf. Iridaceae and Burmanniaceae?). APG (1998) Monocot; non-commelinoid; Asparagales (as a synonym of Iridaceae). Species 1. Genera 1; only genus, Geosiris.
Description inadequate for reliable taxonomic asignment.
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: 17th June 2009. http://delta-intkey.com’.