Polycarena Benth.

Scientific Description

Family Scrophulariaceae.

Habit and leaf form. Herbs, or shrubs (rarely). Annual, or perennial; plants with neither basal nor terminal concentrations of leaves; to 0.3 m high. Helophytic, or mesophytic, or xerophytic. Leaves minute to medium-sized; opposite, or alternate and opposite (then alternate above); when alternate spiral, or four-ranked; ‘herbaceous’, or leathery, or membranous; petiolate, or sessile; simple; epulvinate. Leaf blades entire; linear, or ovate, or obovate, or elliptic; pinnately veined. Mature leaf blades adaxially pubescent, or villous; abaxially pubescent, or villous. Leaves without stipules. Leaf blade margins entire, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present; glandular hairs present, or absent; 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 spikes, or in heads. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; at first capitate, becoming elongated in fruit, rarely elongated or interrupted at the start. Flowers pedicellate to subsessile; bracteate; ebracteolate; minute to small; regular, or very irregular; zygomorphic; 5 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed. Calyx lobes markedly shorter than the tube, or about the same length as the tube, or markedly longer than the tube. Calyx imbricate, or valvate; campanulate, or tubular; bilabiate, or regular; persistent; when K5, with the median member posterior. Calyx lobes oblong, or ovate, or linear. Corolla present; 5; 1 -whorled; gamopetalous; lobed. Corolla lobes about the same length as the tube, or markedly longer than the tube. Corolla imbricate, or valvate; campanulate, or funnel-shaped; regular, or unequal but not bilabiate (when lobes subequal), or bilabiate (obscurely); glabrous abaxially; plain; white, or yellow, or pink; persistent, or deciduous. Androecium 4. Androecial members adnate (to the corolla); markedly unequal; free of one another; 1 -whorled. Stamens 4; becoming exserted (slightly), or remaining included; didynamous; all more or less similar in shape; reduced in number relative to the adjacent perianth; oppositisepalous. Anthers dehiscing via longitudinal slits; introrse; unilocular (by confluence); 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), or not becoming exserted. Stigmas 1; 1 - lobed. 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; not hairy; not spinose; dehiscent; a capsule. Capsules septicidal. Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds small; winged (wings 3), or wingless (angled). Cotyledons 2. Embryo straight to curved.

Special features. Corolla tube straight.

Geography, cytology, number of species. Adventive. Australian states and territories: Western Australia and South Australia. South-West Botanical Province.

Etymology. From the Greek for "many" and "head"; referring to the many terminal clusters of flowers of some species.