Family Geosiridaceae

Geosiridaceae Jonker

~ 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. Dahlgren et al. Superorder Liliiflorae; Liliales (cf. Iridaceae and Burmanniaceae?). APG 3 core angiosperms; Superorder Lilianae; non-commelinid Monocot; Order Asparagales (as a synonym of Iridaceae).

Species 1. Genera 1; only genus, Geosiris.

Description inadequate for reliable taxonomic assignment.