Viola collina, Besser Viola ambigua, Waldst. & Kit. Viola chelmea, Boiss. & Heldr. Viola chelmea subsp. vratnikensis, Gayer & Degen

7. V. collina Besser View in CoL , Cat. Pl. Horto Cremen. 151 (1816).

Like 6 but leaves with deeper sinus; stipules linear to oblong-lanceolate, longer-fimbriate and more hairy; bracts above middle of peduncle; flowers pale blue, fragrant; spur whitish and shorter. 2« = 20. Usually calcicole. Scattered over a large part o f Europe, but absent from the Balkan peninsula, the islands and much o f the north. Au Be?Co Cz Fe Ga Ge He Hs Hu It Ju No Po Rm Rs (N, B, C W E) Su.

8. V. ambigua Waldst. & Kit. View in CoL , Pl. Rar. Hung. 2: 208 (1804).

Perennial with leaf-rosette; rhizome stout, more than 2 mm thick. Leaves oblong-ovate with truncate base, usually sparsely hairy, later glabrescent. Stipules 1-1-5 cm, dark green, broadly lanceolate, shortly glandular-fimbriate, ciliate. Peduncles scarcely exceeding the leaves; bracts at or below middle. Flowers 1-1-5 cm, fragrant. Sepals c. 3 - 5 mm, oblong. Petals dark violet. Spur 2-4 mm, curved, stout. Capsule pubescent. 2zi = 40. Calcifuge. From E.C. Russia westwards to Macedonia and E. Austria. Au Bu Cz?Ge Hu Ju Rm Rs (C, W, K, E).

9. V. thomasiana Song View in CoL . & Perr. in Billot, Annot. 183 (1860).

Like 8 but rhizome slender, less than 2 mm thick; leaves shallowly cordate; stipules 0-5—1 cm, linear-lanceolate, densely ciliate; sepals c. 2-5 mm; petals lilac or almost white; spur slender. 2/7=20. Usually above 1000 m; calcifuge. • C. & S. Alps. Au Ga He It.

10. V. pyrenaiea Ramond ex DC. View in CoL in Lam. & DC., Fl. Fr. ed. 3, 4: 803 (1805).

Perennial 8-10 cm, with short, erect rhizome and leaf-rosette. Spring leaves broadly ovate, cordate, glabrescent; summer leaves subacuminate, shining. Stipules lanceolate, shortly glandular-fimbriate, ciliate. Peduncles 3-5 cm; bracts at or above middle. Flowers c. 1-5 cm, pale violet with white throat, fragrant. Sepals broadly ovate, obtuse. Spur pale violet. Capsule glabrous. 2/i = 20. Subalpine habitats. Pyrenees, Alps and Jura; one station in C. Appennini ; mountains o f Balkan peninsula. Al Au Bu Ga G r He Hs It Ju. V. prenja G. Beck , Ann. Naturh. Mus. (Wien) 2: 81 (1887), described from alpine rocks in W. Jugoslavia (Prenj Planina), is like 10 but has flowers c. 1 cm. It is probably best regarded as a variety of 10.

11. V. chelmea Boiss. & Heldr. View in CoL in Boiss., Diagn. Pl. Or. Nov. 3(1): 54 (1853).

Perennial 4-8 cm, with short, erect rhizome and leaf-rosette. Lamina of spring leaves 0-5-1 -5 cm, much shorter than petiole, triangular, truncate or cuneate at base, rather hairy; summer leaves larger, similar in shape, glabrous. Stipules broadly lanceolate, glandular-fimbriate. Flowers 1 cm, not fragrant. Sepals obtuse or subacute. Petals pale violet, not darkly veined. Spur rather stout, shorter than sepals. Capsule glabrous. Calcareous rocks, 500-2200 m. • W. Jugoslavia and Greece. Gr Ju.

(a) Subsp. chelmea :

Stipules fimbriate, glabrous. Bracts of the peduncle narrow, glabrous or sparsely ciliate. 2« = 20. Mountains of Greece.

(b) Subsp. vratnikensis Gayer & Degen View in CoL , Magyar Bot. Lapok 13: 309 (1914):

Stipules long-fimbriate; fimbriae equalling the breadth of the stipule, ciliate. Bracts of the peduncle wide at the base, ciliate. W. Jugoslavia.

V. vilaensis Hayek , Denkschr. Akad. Wiss. Math.-Nat. Kl. (Wien) 94: 154 (1918), from screes in Cm a Gora (near Rikavac, on the Albanian frontier), is a variant of 11 with stipules slightly hairy at the apex, and pale lilac or white petals with dark veins. Species of Sect. Viola , subsect. Viola (1-11) frequently hybridize with one another, but very rarely with species of other subsections. Of the 30 or more hybrids described the following 5 are probably the most frequent; all but the fifth are stoloniferous: V. alba x odorata , V. collina x odorata , V. hirta x odorata (V. x permixta Jordan), V. alba x hirta , V. collina x hirta .