Hyssopus officinalis, L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 170

1. H. officinalis L. , Sp. PI. 569 (1753).

Stems 20-60 cm, numerous, erect, rarely decumbent. Leaves 10-50 x 1-10 mm, linear, lanceolate or oblong, obtuse to acuminate, entire, glabrous to villous, sessile or subsessile. Bracts linear, acuminate, not aristate or with an arista 1-3 mm. Calyx glabrous or puberulent, the tube 3-5 mm, the teeth 1-3 mm, acuminate, aristate or not. Corolla 7-12 mm, blue or violet, rarely white. Nutlets c. 2 mm. Dry hills and rocky ground. S., S.C. & E. Europe; locally naturalized from gardens elsewhere. Al Au Bu Cz Ga He Hs Hu It Ju Rs (B, C, W, K, E) [Be Ge Ho Po].

A polymorphic species, in which variants have been named at the specific, subspecific and varietal level, mainly on the basis of differences in indumentum, presence or absence of aristae on bracts and calyx-teeth, and length of calyx-teeth. Although their geographical range is sometimes discontinuous, the most distinctive variants are treated here as subspecies. Further research is needed to ascertain their proper status.

1 Plants greyish- or whitish-villous (a) subsp. canescens

1 Plants glabrous or glabrescent

2 Calyx-teeth 1 mm, triangular, not aristate; corolla exceeding calyx-teeth by 3 mm (b) subsp. montanus

2 Calyx-teeth 2-3 mm, lanceolate or ovate-lanceolate, with an arista 1-3 mm; corolla exceeding calyx-teeth by 4 mm

3 Bracts aristate (c) subsp. aristatus

3 Bracts not aristate (d) subsp. officinalis