Acanthus L.
Perennial herbs or shrubs. Stems simple, erect. Lvs mostly radical, pinnatifid to pinnatisect; margins sometimes spiny. Fls strongly zygomorphic, arranged in dense spike-like infls. Bracts large, spinose-dentate; bracteoles entire. Calyx 4-lobed; upper and lower lobes larger, sometimes spine-tipped; lateral lobes very small. Corolla 1-lipped (only lower lip present); lip 3-5-lobed; tube short. Stamens 4, included; filaments thick and prominent; anthers fused in pairs, 1-celled, often white-villous. Ovules 2 per cell. Style shortly 2-lobed. Capsule oblong or ovoid, 4-seeded.
c. 50 spp., Old World tropics and subtropics, a few in S. Europe. Naturalised sp. 1.
