Verbena bonariensis

Herb 0.5–2 m high; branches erect, conspicuously quadrangular, scabrous-pubescent or hispidulous especially on angles. Leaves sessile, lanceolate, ovate-lanceolate or oblong-lanceolate, (3–)5–15(–18) cm long, (0.5–)1–3.5(–5) cm wide, rugose and scabrous above, tomentose below, apex acute, base cordate and sub-auriculate to amplexicaul, margin coarsely incised-serrate, sometimes entire toward base. Inflorescence lax, terminal, corymbose or spike-like. Bracts barely equalling or slightly longer than calyx. Calyx 5- (rarely 4-) toothed, 2.5–3.5 mm long, pubescent-hispidulous on angles outside, glabrous inside, non-glandular; corolla blue, dark-purple, pinkish, lilac or mauve, as long as or twice as long as calyx, tube 3–5(–6) mm long. Mericarps 1–2 mm long.