The families of flowering plants.
Habit and leaf form. Erect herbs. Perennial; more or less with a basal aggregation of leaves; cormous (the corm bulb-shaped, tunicated, including more than one internode). Leaves alternate; spiral; flat; sessile; sheathing; simple. Lamina entire; linear, or lanceolate; parallel-veined; without cross-venules. Lamina margins entire.
Leaf anatomy. Stomata present; anomocytic.
The mesophyll containing calcium oxalate crystals. The mesophyll crystals raphides.
Stem anatomy. Secondary thickening absent.
Reproductive type, pollination. Unisexual flowersabsent. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the gynoecium (?).
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. The ultimate inflorescence unit cymose. Inflorescences scapiflorous to not scapiflorous (the scape leafy at least below); terminal; panicles with varying degrees of branching, often few-flowered, sometimes umbel-like. Flowers medium-sized; regular; 3 merous; cyclic; pentacyclic. Perigone tube absent.
Perianthof ‘tepals’; 6; free; 2 whorled; isomerous; petaloid; similar in the two whorls (but the outer members somewhat narrower); nearly white, or violet, or blue.
Androecium 6. Androecial members adnate (to the bases of the tepals); free of one another. Androecium exclusively of fertile stamens. Stamens 6; diplostemonous; filantherous (the filaments long and slender). Anthers basifixed; non-versatile; dehiscing via longitudinal slits; latrorse to introrse; tetrasporangiate. Endothecium developing fibrous thickenings. The endothecial thickenings spiral. Microsporogenesis simultaneous. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate; sulcate; 2-celled.
Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil 3 celled. Gynoecium syncarpous; synstylovarious; inferior. Ovary 3 locular. Epigynous disk absent. Gynoecium stylate. Styles 1; apical; much longer than the ovary. Stigmas 3 (the style apically tribrachiate); dry type. Placentation axile. Ovules 15–50 per locule (‘rather numerous’); ascending; anatropous; crassinucellate. Endosperm formation helobial.
Fruit non-fleshy; dehiscent; a capsule. Seeds endospermic. Embryo well differentiated (nearly as long as the endosperm). Cotyledons 1. Embryo straight (fusiform). Testa encrusted with phytomelan; black.
Physiology, biochemistry. Alkaloids absent (by contrast with Amaryllidaceae).
Geography, cytology. Holarctic and Paleotropical. Southwest Asia. X = 12.
Taxonomy.Subclass Monocotyledonae. Dahlgren et al. Superorder Liliiflorae; Asparagales. APG 3 core angiosperms; Superorder Lilianae; non-commelinid Monocot; Order Asparagales.
Species 1–4. Genera 1; only genus, Ixiolirion.