Droseraceae

Primary tabs

Droseraceae

Description

Annual or perennial insectivorous herbs. Roots adventitious (some extra-neotropical species with tubers). Stems 0.1-30 cm, aerial (subterranean in some extra-neotropical species). Leaves generally stipulate, alternate, simple (variously lobed or peltate in some extra-neotropical species), covered with glandular hairs; stipules intrapetiolar (lateral or absent in some extra-Guianan species); petiole grading into blade or well defined, hairy or glabrous; blade membranaceous, linear to circular, margin covered with glandular hairs. Inflorescences terminal, rarely lateral, unbranched, one-sided or dichasial cymes, sometimes flowers solitary; peduncle slender, up to 20 cm long, with glandular hairs, non-glandular hairs or glabrous (also in bracts, pedicels and sepals); bracts minute, green, red or scarious; pedicels present. Flowers generally 5-merous, actinomorphic (zygomorphic in some extra-tropical species), hermaphrodite; sepals joined at base or free; petals free, white or pink, rarely yellow, membranaceous, spathulate or obovate, usually persistent; stamens generally 5, filaments filiform, terete, anthers usually bilocular; pollen generally released in tetrads, generally spinulose; ovary superior, glabrous, carpels generally 3, united, placentation parietal, styles 3-5, usually partite at base or unbranched, rarely united, often further dividing distally, stigmas tapered or swollen, often papillose. Fruits dehiscent (rarely indehiscent in extra-Neotropical species), papery capsules; seeds numerous (few in some extra-Neotropical species), embryo embedded in copious endosperm, rich in starch, oil and protein, cotyledons minute.

Distribution

Australasia: Cosmopolitan: present Neotropics: present
Cosmopolitan with centre of diversity in Australia, 4 genera and ca. 120 species, the genus Drosera is the only one in the Neotropics.

Ecology

The Droseraceae is a family of insectivorous (carnivorous syndrome) herbs; commonly growing in bogs and other waterlogged soils; the carnivorous habit may be an evolutionary response to their growth in media containing little nitrogen.

Uses

Aldrovandra, Dionaea, Drosophyllum and several Drosera's from the Old World are grown, usually in greenhouses as curiosities and as ornamental plants.