Verbascum L.

Scientific Description

Common name. Mulleins. Family Scrophulariaceae.

Habit and leaf form. Herbs, or shrubs (rarely). Annual, or biennial, or perennial. Leaves basal and cauline. Plants with a basal concentration of leaves; to 2 m high. Helophytic, or mesophytic, or xerophytic. Leaves medium-sized to very large; alternate; when alternate spiral, or four-ranked; ‘herbaceous’, or leathery, or membranous; petiolate to sessile (or stem-clasping above); simple; epulvinate. Leaf blades dissected, or entire; ovate, or obovate, or oblong, or elliptic; if dissected pinnatifid (or lobed); pinnately veined. Mature leaf blades adaxially glabrous, or pubescent; abaxially glabrous, or pubescent. Leaves without stipules. Leaf blade margins entire, or crenate, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes present (occasionally), or absent. Hairs present, or absent; glandular hairs present, or absent. Unicellular hairs present, or absent. Complex hairs present, or absent. Complex hairs stellate. 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, or in panicles. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary. Flowers pedicellate; bracteate; bracteolate, or ebracteolate; small to medium-sized; more or less regular, or somewhat irregular; 5 merous; tetracyclic. Free hypanthium absent. Hypogynous disk present. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; polysepalous, or gamosepalous; lobed. Calyx lobes markedly longer than the tube. Calyx imbricate, or valvate; more or less regular, or unequal but not bilabiate (lobes unequal); persistent; when K5, with the median member posterior. Sepals elliptic. Calyx lobes elliptic. Corolla present; 5; 1 -whorled; gamopetalous; lobed. Corolla lobes markedly longer than the tube. Corolla imbricate, or valvate; rotate; regular, or unequal but not bilabiate (lobes subequal); hairy abaxially; plain, or with contrasting markings; yellow, or white, or pink, or purple (centred). Androecium 4, or 5. Androecial members adnate (to the corolla); all equal, or markedly unequal (lower 2 filaments longest); free of one another; 1 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present 1. Stamens 4 (with or without a staminode), or 5; didynamous (when staminode absent), or not didynamous, not tetradynamous; all more or less similar in shape (all reniform), or distinctly dissimilar in shape (lower 2 anthers obliquely inserted and adnate to the filament); reduced in number relative to the adjacent perianth, or isomerous with the perianth; oppositisepalous. Filaments hairy, or hairy and glabrous (then lower 2 glabrous). Anthers dimorphic, or all alike; 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; 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; not spinose; dehiscent; a capsule. Capsules septicidal. Fruit 50 seeded (to ‘many’). Seeds endospermic. Endosperm oily. Seeds minute to small. Cotyledons 2. Embryo straight to curved. Testa pitted.

Special features. Corolla tube straight.

Geography, cytology, number of species. Adventive. 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 Latin verbascum; the name of the plant.