Marrubium vulgare, 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 : 138

10. M. vulgare L. , Sp. Pl. 583 (1753).

Stems up to 45 cm, white-lanate at least below, with many short non-flowering branches. Leaves orbicular to broadly ovate, subcordate or rounded at base, deeply and irregularly crenate, sparsely tomentose to subglabrous above, more densely tomentose beneath; petioles of lower leaves shorter than lamina. Verticillasters globose, many-flowered, distant. Bracteoles subulate, villousplumose. Calyx-tube 3-4 mm, obscurely 10-striate, villouspubescent; teeth 10, shorter than corolla, equal, patent, hamate, villous beneath, glabrous above. Corolla exceeding calyxteeth, white. 2n = 34. Waste places. Europe, from England, S. Sweden and C. Russia southwards. All except Fa Fe Is No Rs (N) Sb; only as an alien in Hb.

In Spain intermediates (possibly hybrids) between 10 and 4 are found; these resemble 4, but have 10 calyx-teeth, 5 longer alternating with 5 shorter. They lack the plumose bracteoles of 4, and the calyx-teeth are sometimes slightly hamate. They have been called M. x willkommii Magnus ex Pau , Bol. Soc. Ibér. Ci. Nat. 25:76 (1926).