I.C. Hedge

Suffruticose perennials, aromatic. Stems numerous, branched or unbranched, with very short ± adpressed eglandular hairs, leafy, clearly quadrangular, rather slender. Leaves sessile, linear to oblong-linear, entire, usually with clusters of younger leaves in leaf axils, strongly gland-dotted. Cymes pedunculate in axils of upper leaves, numerous, forming mainly terminal spikes, often secund. Bracts present. Calyx tubular, widened at throat, 15-ribbed, scarcely bilabiate; with 5 subequal teeth, usually with thickened tissue at base of sinuses; tube glabrous at throat. Corolla violet blue, bilabiate; upper lip flat, emarginate, glabrous or pilose; lower lip 3-lobed with a clearly larger median emarginate lobe; tube ± curved, usually clearly exserted from calyx, pilose but not annulate within. Stamens 4, clearly exserted beyond corolla lobes, spreading, scarcely didynamous; thecae bilocular, spreading, glabrous. Stylar branches 2, subequal. Nutlets narrow oblong, weakly trigonous, apically rounded, mucilaginous on wetting.

Variously regarded as monotypic or having up to c. 10 weakly differentiated species in Europe, N. Africa, SW and C. Asia, NW Himalaya.

Lower Taxon

• Hyssopus officinalis L.