Botany · Ch 12 — Taxonomy of Angiosperms
Family Liliaceae
Family Liliaceae
Family Liliaceae: Classification and Vegetative Characters
Family Liliaceae belongs to the class Monocotyledonae, and within that class it is placed under the series Coronariae in Bentham and Hooker's scheme. Being a monocot family, Liliaceae shows the characteristic trimerous floral plan (parts in threes) rather than the pentamerous plan of the two dicot families, Fabaceae and Solanaceae, already covered in this chapter.
I. Vegetative characters: members are mostly perennial herbs, and a defining vegetative feature of the family is the frequent presence of underground perennating and storage organs such as bulbs, rhizomes, or corms — the everyday onion bulb is the most familiar example. The root is adventitious, arising from the stem base rather than from a persisting primary root, and is fibrous or, in some members, fleshy. The stem proper is usually reduced to a short underground portion bearing the bulb or corm, although an aerial flowering stalk (scape) may arise from it to carry the inflorescence. The leaf is generally simple, with parallel venation typical of monocots (unlike the reticulate venation of Fabaceae and Solanaceae), and it has a sheathing base that wraps around the stem.
II. Floral characters: the inflorescence may be a raceme, an umbellate cyme (as in onion, where flowers radiate from a single point atop the stalk), or a solitary flower. The flower is bisexual, actinomorphic, and trimerous. Because the calyx and corolla are not clearly distinct from each other in this family, the whole outer whorl-set is described as a single perianth of six similar, coloured, petal-like segments called tepals, arranged in two whorls of three and often fused at the base. The androecium has six stamens in two whorls of three, matching the two perianth whorls; the anthers are dithecous, basifixed, introrse (facing inward toward the flower's centre), and they dehisce longitudinally. The gynoecium is tricarpellary and syncarpous (three carpels fused into one compound pistil), with a superior, trilocular ovary and axile placentation. Pollination is mostly entomophilous, and the fruit is typically a capsule, occasionally a berry.