566 



VIOLACEAE 



Pedimcles of cleistogamoiis flowers usually 4-6 cm. long, erect 

 or ascending. 2. V. pratincola. 



Spurred petal more or less bearded, retuse or emarginate. 

 Spurred petal somewhat bearded, mostly retuse. 



3. V. retusa. 

 Spurred petal thickly bearded, emarginate. 4. V. nephrophylla. 



V. septcnlrionalis. 

 V. pedatifjda. 

 V. Sclkirkii. 

 V. renifolia. 



9. 

 10. 



11. 



12. 



V. palustris. 

 V. Macloskeyi. 



V. sempervirens. 

 V. orbiculata. 



14. V. Sheltonii. 



15. V. venosa. 



16. V. linguaefolia. 



17. 

 18. 



V. vallicola. 

 V. Nuttallii. 



19. V. biflora. 



Leaves and scapes liirsutulous. 

 Leaves 2-3-ternately parted. 

 Rootstock slender. 

 Flowers white. 

 Plants stoloniferous. 

 Flowers not yellow. 



Flowers wliite or lilac; petioles glabrous. 

 Flowers white; petioles after flowering pilose. 

 Flowers yellow. 



Stolons several, long, prostrate, leafy. 

 Stolons few, short, ascending, with 1-3 leafy bracts 

 Plants caulescent, or with manifest stems. 

 Leaves compound or much dissected. 



Upper petals deep violet, the lower pale violet, vrith yellow base. 



13. V.Beckwithii 

 All the petals pale yellow. 

 Leaves simple, not dissected. 

 Flowers yellow. 



First peduncles from the base of the stems. 

 Basal leave!; round, 5-7-lobed or -toothed. 

 Basal leaves ovate to lanceolate, denticulate. 

 Basal leaves 5-9 cm. long, ovate to elliptic. 

 Basal leaves 2-5 cm. long. 



Basal leaves narrowly ovate, obtuse. 

 Basal leaves lanceolate, acute or subacute. 

 First pedimcles from the upper half of the stem. 

 Style and lateral petals beardless. 

 Stjle and lateral petals bearded. 



Upper part of stem and its leaves nearly glabrous. 



20. V. glabella. 

 Upper part of stem and its leaves densely short-pubescent. 



21. V''. pubescens. 

 Flowers not yellow. 



Petals white on the inner face, with a yellow base, 

 purplish. 

 Underground stolons present. 

 Stolons lacking. 



Stems ui^ually 15-35 cm. high. 

 Stems usually 10-15 cm. high. 

 Petals -violet or purple. 



Stipules sharply or bristly toothed; perennials. 

 Plant dwarf; leaves cuneate, glabrous. 

 Plant over 1 dm. high, usually puberulent. 

 Leaves 2-3 cm. long, seeds 1.5 mm. long. 

 Leaves 3-5 cm. long, seeds 2 mm. long. 

 Stipules leaf-like, pectinate at base; annuals. 



1. V. papilionacea Pursh. Plants robust and hardy from a stout branch- 

 ing rootstock, usually glabrous, but petioles sometimes sparsely pubescent; 

 blades when fully grown often 12 cm. wide, reniform or broadly ovate-cordate, 

 acute or abruptly pointed; outer sepals ovate-lanceolate; upper and lateral 

 petals broadly obovate, 8-10 mm. wide. Fields and groves: Mass. — Ga. — Okla. 

 — Minn.; apparently introduced in gardens and along irrigation ditches in 

 Denver, Colo., and vicinity. 



2. V. pratincola Greene. Plant every way smaller than the preceding; 

 leaves deeply cordate-ovate, tapering gradually to a subacute apex, 2-3 cm. wide 

 at petaliferous flowering, 5-8 cm. wide at maturity; petals spatulate, 4-6 mm. 

 wide; peduncles taller than the leaves. Hills and prairies: Colo. — Wyo. — N.D. 

 Plain — Submont . 



3. V. retusa Greene. Glabrous throughout; leaves at flowering time 

 broadly cordate-deltoid, finely serrate; later leaves much dilated, with a shallow 

 sinus, more or less decurrent on the petiole, often abruptly acuminate; cleistoga- 

 mous flowers on erect peduncles; capsules ellipsoid, green; seeds brown, 2 mm. 

 long. Borders of streams: Kans. — Colo. Plain. My-Je. 



4. V. nephrophylla Greene. Leaves broadly cordate-ovate to reniform, 

 obtuse or bluntly short-pointed; petals large, tlie upper pair often sparsely 

 pubescent; sepals ovate to lanceolate, obtuse; cleistogamous flowers on erect 



