Habit and leaf form. Herbs (small to medium); evergreen, or deciduous. Perennial (annual leaves and flowers). Leaves cauline, or basal and cauline. Plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves; cormous (tuber-like, persistent, 1 more each year, naked or with a membranous tunic). Helophytic to xerophytic. Leaves alternate; distichous; ‘herbaceous’, or leathery; sessile; sheathing. Leaf sheaths with free margins. Leaves foetid, or without marked odour; edgewise to the stem, or with ‘normal’ orientation; simple; epulvinate. Leaf blades entire; flat, or solid; linear, or lanceolate; linear (basal- broadly, to ensiform); parallel-veined (prominent midrib); without cross-venules; open or closed sheaths. Leaves eligulate; without stipules. Leaf blade margins entire. Leaves with a persistent basal meristem, and basipetal development. Leaf anatomy. Hairs absent (often glaucous). Extra-floral nectaries absent. Stem anatomy. Secondary thickening absent.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Floral nectaries present, or absent. Nectar secretion from the perianth (from nectaries at the tepal bases). Entomophilous, or ornithophilous, or anemophilous.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes, or in corymbs (of few-numerous cymes). The terminal inflorescence unit cymose, or racemose. Inflorescences terminal; scape erect, branched, leafy; cymes of 2,3 or 6-flowered rhipidia; spatheate (2 per rhipidium, large, opposed, persistent, herbaceous; outer shorter than inner, ovate to elliptic and keeled with margins white or translucent). Flowers pedicellate (very short); bracteate (at the base of the pedicels, membranous); ebracteolate; small to large; regular; 3 merous; cyclic; tetracyclic. Perigone tube present. Perianth of ‘tepals’; 6; 2 -whorled; isomerous; petaloid; without spots, or spotted; similar in the two whorls, or different in the two whorls; purple (purple-black, or maroon to black). Androecial members definite in number. Androecium 3. Androecial members free of the perianth, or adnate (to the perianth tube); all equal; coherent; when united, 1 - adelphous; 1 -whorled (representing the outer whorl). Androecium exclusively of fertile stamens. Stamens 3; all more or less similar in shape; reduced in number relative to the adjacent perianth to isomerous with the perianth; opposite the outer perianth segments; alterniperianthial (opposite the outer perianth lobes). Anthers basifixed; versatile; dehiscing via longitudinal slits; extrorse. Gynoecium 3 carpelled. The pistil 3 celled. Gynoecium partly petaloid, or non-petaloid; syncarpous; synstylovarious; inferior. Ovary plurilocular; 3 locular. The ‘odd’ carpel anterior. Gynoecium stylate. Styles 1; apical. Stigmas 3. Placentation axile. Ovules 20–50 per locule (many); arillate, or non-arillate; anatropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (from the apex). Fruit 3 celled; 20–100 seeded (many). Seeds endospermic. Endosperm oily. Cotyledons 1 (coleoptile-like). Embryo straight (small). Testa without phytomelan.
Etymology. After J. B. Ferrari (1584–1655), an Italian botanist who first illustrated the genus in 1633.