Its nearest affinity is with S. disermas which, together with S. radula, has the upper calyx lip with the 3 teeth connivent as in S. verbenaca. S. verbenaca tends to be smaller in stature with shorter calyx and corolla, and the upper lip of the corolla is not as distinctly falcate (often almost straight). Also, the leaves of S. verbenaca often have more deeply dissected margins than those of S. disermas, but depauperate specimens of the latter are sometimes difficult to identify with certainty.
Perennial, probably short-lived, with stems arising from a woody taproot; stems erect, 0.15-0.4 m tall, densely glandular-villous with long spreading hairs and shorter gland-tipped hairs. Leaves mainly a dense basal rosette, shortly petiolate to subsessile, blade irregularly to deeply pinnatifid or sometimes almost entire, usually oblong to ovate-oblong in outline, 40-130 x 10-30 mm, rugose and usually densely pubescent and gland-dotted below, margin often eroso-dentate. Inflorescence usually branched with many verticils, spaced below and denser above; verticils usually 6-flowered. Calyx pilose and gland-dotted, densely villous in the throat, up to 8 mm long in fruit. Corolla light blue to purple, 8-12 mm long; tube 4-8 mm long; upper lip often slightly falcate, 2-4 mm long, lower lip usually slightly shorter.
Like S. runcinata but upper lip of calyx with teeth connivent.
Perennial herb, 0.15-0.40 m high. Stems erect, densely glandular-villous with long, spreading hairs and shorter gland-tipped hairs. Leaves in a dense, basal rosette; blade oblong to ovate-oblong, 40-130 x 10-30 mm, margins irregularly to deeply pinnatifid, sometimes almost entire. Flowers: verticils 6-flowered; calyx 7-9 mm long, upper lip with 3 closely connivent, short teeth, pilose and gland dotted, densely villous in throat; corolla 8-12 mm long, upper lip of corolla straight or slightly falcate, light blue to purple; Sep.-Mar.
Probably indigenous in the countries around the Mediterranean and on the Canary Islands and has spread further afield in Europe and Asia.
Bokkeveld Escarpment to Riversdale, widespread though drier parts of southern Africa into Mediterranean.