plectranthus scutellarioides  

23. Plectranthus L'Herit

Perennial herbs or shrubs, aromatic or not. Leaves petiolate, undivided, succulent or non-succulent crenate to serrate. Verticillasters lax or approximate, arranged in panicles or spikes. Flowers violet or blue. Calyx bilabiate, campanulate; upper lip of a broadly ovate lobe, lower lip of 4 acuminate teeth; usually calyx-tube annulate within; accrescent and deflexed-spreading in fruit. Corolla bilabiate; upper lip short 4-lobed; lower lip boat-shaped (cucullate), entire, longer than the upper; tube exserted, usually curved and inflated above. Stamens 4, declinate, didynamous; filaments in some united in a basal sheath, glabrous or hairy; thecae unilocular. Style subequally bifid. Nutlet subspherical, ovoid to oblong, mucilaginous or not on wetting.

Of its c. 200 species, it is represented by at least 6 species in Saudi Arabia.