Ballota nigra, 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 : 150

7. B. nigra L. , Sp. Pl. 582 (1753).

Perennial up to 130 cm. Stems pubescent to subglabrous. Lower cauline leaves 3-8 x 2-6 cm, cordate to cuneate at base, ovate or ovate-oblong; petiole usually short, rarely up to 80 mm. Bracteoles 3-9 mm, subulate or filiform, membranous. Verticillasters many-flowered. Calyx 7-13 mm; limb regularly dentate; lobes 5, awned or mucronate. Corolla 9-15 mm, pink, lilac or white. 2« = 22. Europe, from England, S. Sweden and C. Russia southwards as a native or naturalized alien; casual or imperfectly naturalized further north. All except Fa Fe 1$ No Rs (N, B) Sb.

Doubtfully native in much of N.W. & N. C. Europe; the limits of native distribution cannot be precisely ascertained.

A polymorphic species with 6 subspecies in Europe.

1 Calyx-lobes (3-)4-6-5 mm, triangular- to subulate-lanceolate, awned; awn 1 -5-3 mm (a) subsp. nigra 1 Calyx-lobes 1-3 mm, ovate to triangular-ovate, acuminate, mucronate; mucro 0-2—0 -8(— 1 -7) mm

2 Calyx-lobes erect or erecto-patent

3 Calyx scarcely widened above; plant sericeous-tomentose, with shining, sessile glands (b) subsp. sericea 3 Calyx infundibuliform above; plant subglabrous or pubescent, with papillae and non-shining, sessile glands

(c) subsp. foetida 2 Calyx-lobes curved and patent

4 Plant greyish-tomentulose-velutinous, with numerous sessile glands; stems not more than 30 cm, little-branched

(d) subsp. velutina 4 Plant pubescent to subglabrous, rarely sericeous-tomentulose, without sessile glands; stems up to 80 cm, much-branched

5 Calyx 9-11 mm, the lobes with mucro 0-2-0-8 mm; corolla

lilac (e) subsp. uncinata 5 Calyx 7-8 mm, the lobes with mucro 1-1-5 mm; corolla pink

(f) subsp. anatolica