Common name. Burmannia Family.
Habit and leaf form. Herbs. ‘Normal’ plants, or plants of very peculiar form (some being tiny saprophytes); sometimes vegetatively almost filamentous, or fungoid. Leaves well developed, or much reduced, or absent. Autotrophic, or saprophytic. Annual, or perennial; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Leaves alternate; spiral (usually), or distichous; ‘herbaceous’, or membranous; sessile; sheathing. Leaf sheaths with free margins. Leaves simple. Leaf blades entire; usually linear to ovate; parallel-veined; without cross-venules. Vegetative anatomy. Plants without silica bodies. Stem anatomy. Secondary thickening absent. Roots. Roots with velamen, or without velamen.
Reproductive type, pollination. Fertile flowers hermaphrodite, or functionally male and functionally female. Unisexual flowers present, or absent. Plants hermaphrodite, or monoecious. Floral nectaries present. Nectar secretion from the gynoecium (via septal nectaries, or from the top or sides of the ovary).
Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; in cymes and in racemes. The terminal inflorescence unit cymose. Inflorescences terminal; dichasia or monochasia. Flowers regular; 3 merous; cyclic; tetracyclic. Perigone tube present (3-winged). Perianth of ‘tepals’; 6, or 3 (3+3, but either whorl may be reduced or obsolete); 1 -whorled, or 2 -whorled; isomerous; petaloid; different in the two whorls (Burmannia with the inner lobes smaller or absent), or similar in the two whorls. Androecium 3. Androecial members adnate (to the tube); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 3; isomerous with the perianth; when perianth developed, oppositiperianthial (by contrast with Iridaceae etc.). Anthers introrse to latrorse; tetrasporangiate; appendaged (often), or unappendaged. Pollen shed as single grains. Gynoecium 3 carpelled. The pistil 1 celled, or 3 celled. Carpels isomerous with the perianth. Gynoecium syncarpous; synstylovarious; partly inferior. Ovary unilocular, or plurilocular; 1 locular, or 3 locular. Styles 1; partially joined; apical. Stigmas 3. Placentation when unilocular parietal; when trilocular axile. Ovules in the single cavity when unilocular, 15–100 (? — ‘many’); when trilocular 10–50 per locule (? — ‘many’); anatropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules splitting irregularly, or loculicidal, or valvular (rarely). Fruit 15–100 seeded (‘many’). Seeds scantily endospermic; winged. Embryo rudimentary at the time of seed release.
Geography, cytology, number of species. Holarctic, Paleotropical, Neotropical, Australian, and Antarctic. World distribution: widespread, tropical, subtropical, north to Japan and eastern U.S.A., south to Tasmania and New Zealand. 125 species.