Parentucellia Viv.

Scientific Description

Common name. Bartsias. Family Scrophulariaceae.

Habit and leaf form. Herbs. ‘Normal’ plants, or plants of very peculiar form (parasitic). Partially parasitic. On roots of the host. Annual, or biennial; plants with neither basal nor terminal concentrations of leaves; to 0.7 m high. Helophytic, or mesophytic. Leaves small to medium-sized; opposite; ‘herbaceous’, or leathery, or membranous; subsessile to sessile; simple; epulvinate. Leaf blades dissected, or entire; ovate, or triangular; if dissected palmately lobed; pinnately veined. Mature leaf blades adaxially scabrous, or pubescent; abaxially scabrous, or pubescent. Leaves without stipules. Leaf blade margins dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present; glandular hairs present; complex 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 aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal; spike-like. Flowers pedicellate to 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; tubular; more or less regular; persistent; accrescent. Calyx lobes ovate, or triangular. Corolla present; 4 (the posterior pair united); 1 -whorled; gamopetalous; lobed. Corolla lobes markedly shorter than the tube, or about the same length as the tube. Corolla imbricate, or valvate; bilabiate; hairy abaxially; plain; white, or yellow, or red, or purple; persistent, or deciduous. 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 hairy, more or less equally awned at 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; 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; 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. Cotyledons 2. Embryo straight to curved. Testa smooth (or reticulate).

Special features. 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 (lobes incurved); upper (adaxial) lip of the corolla markedly concave (and enclosing the anthers). Lower (abaxial) lip of the corolla 3 lobed (with a ridged palate, the throat not closed).

Geography, cytology, number of species. Adventive. Australian states and territories: Western Australia, South Australia, New South Wales, Victoria, Australian Capital Territory, and Tasmania. South-West Botanical Province.

Etymology. After Tomaso Parentucelli, founder of the botanical gardens at Rome.