Citation: L., L., Sp. Pl. 20 (1753).

Derivation: Applied by German botanist, Otto Brunfels, in 1530, to V. officinalis, apparently from verbena, the Italian and Spanish name of this plant, the classical Latin name of which was verbenaca.

Synonymy: Not Applicable

Common name: Purple-top, purple-top verbena.

Description:
Rigid erect scabrous-hairy perennial up to 2 m high; stem sharply and conspicuously quadrangular, somewhat scabrous-pubescent or hispidulous especially on the ridges, often 3-branched at the base; leaves sessile, oblong-lanceolate, half-clasping, 4-22 cm long, 0.6-7 cm wide, coarsely incised-serrate, rugose, scabrid and more or less villous above, tomentose beneath.

Inflorescence spicate; spikes compact terminally, cylindrical, becoming corymbose panicles 0.5-5 cm long in fruit; bracts equalling or shorter than the calyx, concave, lanceolate-acuminate, pubescent or minutely hirsute and ciliate, not glanduliferous; flowers very small; calyx 5-toothed, 2.5-3.5 mm long, pubescent, hispidulous on the angles; corolla blue, a dark violet-purple or lavender-pinkish, with the tube scarcely twice as long as the calyx, pubescent outside and in the throat; the limb small, inconspicuous, nearly regular; stamens of unequal length, included.

V. trichotoma Moench, Suppl. Meth. 131 (1802); V. quadrangularis Vell., Conc. Fl. Flum. 16 (1825); Ic. 1:t. 39 (1836).

Published illustration: Rickett (1970) Wildflowers of the United States 2, 2:pl. 170; Cunningham et al. (1982) Plants of western New South Wales, p. 569; Munir in Morley & Toelken (1983) Flowering plants in Australia, fig. 175.

Distribution:  About 250 species, chiefly from temperate and tropical America, with only 2 species native to the Mediterranean region and the near East and introduced elsewhere in the Old World. There are many widely cultivated forms and numerous natural and artificial hybrids. Several American species have become naturalised in various parts of Europe, Asia; Africa and Australia.   W.Aust.; Qld; N.S.W.; Vic..   Native to temperate South America, introduced into and now widespread in other parts of North and South America, West Indies, parts of Europe and Africa, tropical Asia and the Pacific. In many areas it is an aggressive weed in cultivated and otherwise disturbed land.

Biology: No text

Key to Species:

1. Leaves dentate to incise-serrate, sessile, half-clasping; spikes dense both in flower and fruit
2. Bracts shorter than to very slightly surpassing the mature calyx; calyx 2.5-3.5 mm long, pubescent, hispidulous on the angles, not glanduliferous; corolla limb 2.5-5 mm across; corolla tube 3-4.5 mm long	V. bonariensis 1.
2. Bracts conspicuously longer than the mature calyx; calyx 4-6 mm long, glandular-pubescent or hirsute; corolla limb 5-10 mm across; corolla tube 8-10 mm long	V. rigida 3.
1. Leaves (at least the lower ones) deeply incised, pinnatisect or pinnatipartite, shortly petiolate; spikes slender, becoming lax, or dense at the apex but elongated at the fruiting stage
3. Calyx long-tubular, 6-9 mm long; corolla limb 8-10 mm diam.; spikes dense at the apex but elongated at the fruiting stage; leaf blades tripartite-pinnatifid to -pinnatisect, with all the lobes uniformly linear or narrowly linear	V. tenuisecta 5.
3. Calyx c. 3 mm long; corolla limb 2-5 mm diam.; spikes slender, becoming lax; leaf blades pinnatifid or pinnatipartite, with lobes mostly not linear
4. Fruiting spikes 10-25 cm long; calyx 5-toothed; stem scabrid on the angles, usually erect	V. officinalis 2.
4. Fruiting spikes up to 10 cm long; calyx 4-toothed; stem with minute prickles, usually procumbent	V. supina 4.

Author: Not yet available