124 VIOLACEAE 



Fruit a capsule, dehiscent by valves. Seeds anatropous, with a crustaceous testa; 

 embryo straight; endosperm copious. 



A family of IS genera and about 300 species, of wide geographical distribution. 



1. VIOLA* [Tourn.] L. Sp. PL 933. 1753. 



Herbs, with scattered or basal leaves, or some tropical species arborescent. Flowers 

 often of two sorts, the ordinary petaliferous, which are followed later in the season by 

 cleistogamous ones that are usually very fertile. Petals 5, the lowest one usually larger 

 and spurred. Stamens 5, the two lowest with appendages projecting into the spur of the 

 lower petal. [The ancient Latin name.] 



A genus of about 200 species of wide geographical distribution. Type species, Viola odorata L. 



Flowers yellow, or if of some other color, at least with yellow centers; lateral petals with a tuft of very short 

 clavate hairs at base (naked in V. Sheltonii) ; stems well developed. {Chamaemelanium) 

 Leaves divided. 



Lateral petals with a tuft of short clavate hairs at base. 



Upper petals yellow on the inner surface, brownish purple on the back, the others yellow. 



1. V. Douglasii. 



Upper petals violet-purple, the others various. 



Leaves pubescent with short spreading hairs, at least on the margins. 

 Leaves glabrous. 



Lobes of the leaves not 3-nerved nor coriaceous. 

 Lobes of the leaves prominently 3-nerved, becoming coriaceous. 

 Lateral petals glabrous, and all of them pale yellow. 

 Leaves entire, or variously toothed or lobed {V. lobata). 



Inner surface of petals yellow except for dark veining. 



Stems erect, the lower internodes much elongated, the leaves and flowers therefore mostly crowded 

 at the apex. 

 Upper petals brown on the outer surface; leaves palmately lobed except in the subspecies. 



6. V. lobata. 

 Upper petals yellow on the outer surface as well as the inner. 7. V. glabella. 



Stems erect or prostrate, the lower internodes not pronouncedly longer than the upper, the flowers 

 and leaves therefore appearing scattered along the stem. 



Leaves distinctly cordate at base; plants often stoloniferous. 



Stems stoloniferous; leaves dark green above, brownish-punctate on both surfaces. 



8. V. sempervirens. 

 Stems not stoloniferous; leaves bright green above, not brownish-punctate. 



9. V. orbictilata. 



Leaves not cordate at base or sometimes obscurely so in V. peduncutata. 



Rootstock deep-seated, with slender elongated offshoots; inner surface of petals with 

 brownish patch at base. 10. V. peduncutata. 



Rootstock shallow, the flowering stems arising directly from the usually simple crown. 



Ovary glabrous or very sparely pubescent; upper petals not brownish purple on 

 the back. 



Leaves more or less toothed, more or less pubescent; petals bright yellow, often 

 fading purplish on the back, 12-18 mm. long. 11. FT praemorsa. 



Leaves entire, glabrous or slightly puberulent; petals light yellow, not purplish 

 on the back, 8-10 mm. long. 12. V. Bakeri. 



Ovary more or less densely puberulent; upper petals dark brownish purple on the back. 



13. V. purpurea. 

 Inner surface of petals purple or blotched with purple and white, yellow only at center. 

 Flowers purple and white. 



Plants glabrous; petals mainly purple, bordered with white; leaves cuneate at base; stipules 



herbaceous. 14. V. cuneata. 



Plants more or less pubescent; leaves cordate; stipules scarious. 



Stipules fimbriate; inner surface of lateral petals blotched with purple, the others white. 



15. V. ocellata. 

 Stipules entire; inner surface of all the petals white, purple only on the back. 



1 6. V. canadensis. 

 Flowers violet on both surfaces; plants glabrous. 17. V. Flcttii. 



Flowers blue, violet, or white, never yellow; lateral petals with a tuft of very slender elongated hairs at base. 

 (^Nominium) 

 Plants with evident, erect or ascending stems, not stoloniferous (stems short and often horizontal in 

 V. simulata). 

 Head of style bearded; flowers normally violet, rarely white. 

 Leaves and corolla-spur longer than broad. 



Petals 4-5 ram. long, white at base or about to the middle and purple-veined; plants very dwarf, 



almost stemless. 18. V. bellidifolia. 



Petals rarely less than 10-lS mm. long, blue-violet throughout or rarely with a little white 

 at base. 19. V. adunca. 



Leaves and corolla-spur as broad as long. 20. V. Howcllii. 



Head of style naked; petals violet, the lower three often white at base. 21. V. Langsdorfii. 



Plants stemless or producing creeping stolons. 



Plants not stoniferous; rootstocks thick and fleshy; flowers violet. 22. V. nephrophylla. 



Plants producing slender stolons; rootstocks slender. 

 Leaves ovate-cordate. 



Flowers normally blue; leaves distinctly crenate, glabrous. 23. V. palustris. 



Flowers white with purple veins; leaves entire or obscurely and remotely crenate. 



24. V. Macloskeyi. 

 Leaves elliptic; flowers white. 25. V. occidentalis. 



See Appendix for resume on the recent work of Milo S. Baker on Viola. 



