Euphrasia L.

Scientific Description

Common name. Eyebrights. Family Scrophulariaceae.

Habit and leaf form. Shrubs, or herbs. ‘Normal’ plants, or plants of very peculiar form (parasitic). Partially parasitic. On roots of the host. Annual, or perennial; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves; to 0.5 m high. Helophytic, or mesophytic. Leaves minute to small; opposite, or alternate and opposite (then alternate above); when alternate spiral, or four-ranked; decussate; rather fleshy (but brittle); petiolate; simple; epulvinate. Leaf blades dissected, or entire; ovate, or obovate, or elliptic; if dissected pinnatifid; pinnately veined. Mature leaf blades adaxially scabrous, or pubescent; abaxially scabrous, or pubescent. Leaves without stipules. Leaf blade margins entire, or crenate, or serrate, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present; glandular hairs present. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal; spike-like. Flowers pedicellate to sessile; bracteate; ebracteolate; small to medium-sized; very irregular; zygomorphic; 4 merous, or 5 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 9; 2 -whorled; anisomerous. Calyx present; 4; 1 -whorled; gamosepalous; lobed; imbricate, or valvate; campanulate, or tubular; regular, or unequal but not bilabiate (when lobes unequal); persistent. Corolla present; 5; 1 -whorled; gamopetalous; lobed; imbricate, or valvate; bilabiate; plain, or with contrasting markings; yellow, or yellow and brown, or purple, or white, or pink, or blue. Androecium 4. Androecial members adnate (to the corolla); markedly unequal; coherent (forming a U-configuration by fusion along the hairy upper margins of the attenuated pores of each anther loculus with the upper pair of anthers free), or free of one another; 1 -whorled. Stamens 4; inserted at markedly different levels (the posterior pair inserted higher in the corolla tube), or all inserted at the same level; remaining included; didynamous; reduced in number relative to the adjacent perianth; oppositisepalous. Filaments hairy, or glabrous. Anthers cohering, or separate from one another; dehiscing via pores, or dehiscing via longitudinal slits; introrse; bilocular (cells connivent, glabrous or sparsely to densely hairy and awned, the awns often unequal); tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium non-petaloid; syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 2 locular. Gynoecium median; stylate. Styles 1; simple; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1; 1 - lobed, or 2 - lobed (lobes unequal); when entire 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; hairy, or not hairy; not spinose; dehiscent; a capsule. Capsules loculicidal and valvular (by 2 valves). Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute to small. Cotyledons 2. Embryo straight to curved. Testa longitudinally ribbed, scalariform between.

Special features. Corolla tube exceeding the calyx; straight. The upper lip of the corolla incorporating 2 members, the lower 3; (posterior, adaxial) lip of the corolla bilobed (lobes recurved); upper (adaxial) lip of the corolla markedly concave (and enclosing the anthers). Lower (abaxial) lip of the corolla 3 lobed (the throat not closed).

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, South Australia, Queensland, New South Wales, Victoria, Australian Capital Territory, and Tasmania. South-West Botanical Province.

Etymology. From the Greek for "joy, good cheer", perhaps on account of some medicinal properties.