Viola riviniana, Reichenb.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1981, Flora Europaea. Volume 2. Rosaceae to Umbelliferae, Cambridge University Press : 274

18. V. riviniana Reichenb. , Pl. Crit. 1: 81 (1823).

Like 15 in habit, but very variable in size. Leaves from very small to c. 4 cm, cordate, subacute. Stipules of cauline leaves more than 1 cm, lanceolate, fimbriate; fimbriae shorter than in 15. Flowers 1-4-2-5 cm; calycine appendages usually 2-3 mm, more or less conspicuous, the lower accrescent in fruit. Petals rather wide, bluish-violet. Spur 3-5 mm, stout, whitish or light purple, often curved upwards. Stigma glabrous or papillose. 2« = 35, 40, 45, 46, 47. Woodland or grassland. Europe except the south-east. All except Az BI Cr Rs (W, K, E) Sb?Tu. Plants from exposed habitats in W. Europe, with leaves up to 2 cm, flowering branches up to 10 cm and somewhat smaller flowers and fruit than plants from more sheltered habitats, have been distinguished as subsp. minor (Murb. ex E. S. Gregory) Valentine , New Phytol. 40: 208 (1941). As, however, so many intermediate plants and habitats exist, it is probably better to relegate subsp. minor to the rank of variety.