Bartsia L.

Scientific Description

Family Scrophulariaceae.

Includes Bellardia All.

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 neither basal nor terminal concentrations of leaves; to 0.7 m high. Helophytic, or mesophytic, or xerophytic. Leaves small to medium-sized; opposite; decussate; ‘herbaceous’, or leathery; subsessile to sessile; simple; epulvinate. Leaf blades dissected, or entire; linear, or ovate; if dissected pinnatifid; pinnately veined; auriculate at the base to cuneate at the base. Mature leaf blades adaxially pubescent; abaxially 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, or absent. 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 aggregated in ‘inflorescences’; in racemes, or in spikes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal. Flowers pedicellate, or subsessile; bracteate; ebracteolate; small to medium-sized; very irregular; zygomorphic; 4 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 8; 2 -whorled; isomerous. Calyx present; 4; 1 -whorled; gamosepalous; lobed. Calyx lobes markedly shorter than the tube, or about the same length as the tube. Calyx imbricate, or valvate; campanulate, or tubular; unequal but not bilabiate to bilabiate (the median clefts frequently deeper than the lateral ones); persistent; accrescent. Corolla present; 4 (the posterior pair united); 1 -whorled; gamopetalous; lobed. Corolla lobes about the same length as the tube. Corolla imbricate, or valvate; tubular; bilabiate; plain, or with contrasting markings; pink and white, or purple and white, or white, or yellow. Androecium 4. Androecial members adnate (to the corolla); markedly unequal (held in a U-configuration); free of one another; 1 -whorled. Stamens 4; remaining included; didynamous; isomerous with the perianth; oppositisepalous. Anthers dehiscing via pores (pore attenuated); introrse; bilocular (cells equal, parallel, densely hairy with curled hairs or more or less glabrous, each cell equally awned at the base); tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium non-petaloid; syncarpous; 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; becoming exserted (slightly); hairy. Stigmas 1; 1 - lobed, or 2 - lobed; clavate to 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; not spinose (setose); dehiscent; a capsule. Capsules loculicidal and valvular (by 2 valves). Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute; winged, or wingless. Cotyledons 2. Embryo straight to curved. Testa longitudinally ribbed, scalariform between ribs.

Special features. Calyx limb 4 lobed. Upper lip of calyx lobed; 2 lobed. Lower lip of calyx lobed; 2 lobed. Corolla tube exceeding the calyx, or not exceeding the calyx; straight. The upper lip of the corolla incorporating 2 members, the lower 3; (posterior, adaxial) lip of the corolla entire (or emarginate, incurved); 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. Holarctic. Adventive. Australian states and territories: Western Australia, South Australia, New South Wales, and Victoria. South-West Botanical Province.

Etymology. After Johan Bartsch (1709–38), naturalist of Leiden and friend of Linnaeus; the latter recommended him for an appointment at Surinam, South America, where he died. Sometimes incorrectly spelt Bartschia.