Striga Lour.

Scientific Description

Family Scrophulariaceae.

Habit and leaf form. Herbs. ‘Normal’ plants, or plants of very peculiar form (parasitic). Leaves well developed. Partially parasitic. On roots of the host. Annual; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves; to 0.6 m high. Helophytic, or mesophytic, or xerophytic. Leaves minute to medium-sized; alternate, or opposite, or whorled; when alternate spiral, or four-ranked; ‘herbaceous’, or leathery; sessile; non-sheathing; simple; epulvinate. Leaf blades entire; linear to ovate, or triangular (when scale-like); pinnately veined. Mature leaf blades adaxially scabrous, or pubescent; abaxially scabrous, or pubescent. Leaves without stipules. Leaf blade margins entire, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present, or absent; glandular hairs absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous. Pollination mechanism conspicuously specialized (with a loose-pollen mechanism), or unspecialized.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; spike-like. Flowers pedicellate; bracteate; bracteolate; small; very irregular; zygomorphic; 5 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 9; 2 -whorled; anisomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed. Calyx lobes about the same length as the tube. Calyx prominently 5–15 veined; erect; imbricate, or valvate; tubular; unequal but not bilabiate, or bilabiate, or regular; persistent; accrescent; with the median member posterior. Calyx lobes triangular. Corolla present; 4 (the posterior pair united); 1 -whorled; gamopetalous; lobed; imbricate, or valvate; tubular (to salverform); bilabiate; hairy abaxially; hairy adaxially (towards the apex); white, or pink, or purple; not spurred. Androecium 4. Androecial members adnate (to the corolla); markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4; remaining included; didynamous; reduced in number relative to the adjacent perianth; oppositisepalous. Anthers separate from one another; dehiscing via longitudinal slits; introrse; unilocular; tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium non-petaloid; syncarpous; eu-syncarpous; superior. Ovary plurilocular; 2 locular. Gynoecium median; stylate. Styles 1; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1; 1 - lobed; capitate. Placentation axile, or apical. Ovules 50 per locule (to ‘many’); pendulous to ascending; non-arillate; anatropous, or campylotropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (the septum remaining attached to the 2 valves). Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute; wingless. Cotyledons 2. Embryo straight to curved.

Special features. Corolla tube exceeding the calyx; curved. The upper lip of the corolla incorporating 2 members, the lower 3; (posterior, adaxial) lip of the corolla entire (and recurved). Lower (abaxial) lip of the corolla 3 lobed (and porrect or somewhat downcurved).

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia and Northern Territory. Northern Botanical Province and Eremaean Botanical Province.

Etymology. From the Latin for "a row of grain cut down, stiff hair"; the plant is clothed with stiff hairs.