350 BRASSICACEAE 



14. C. oligosperma Nutt. Perennial; stem 1-4 dm. high, pubescent; leaves 

 with 5-11 oval or orbicular, stalked divisions; petals spatulate, about 2.5 mm. 

 long; pods erect, on ascending pedicels, 2-3 cm. long, over 1 mm. wide; beak 

 about 0.5 mm. long. Wet places: B.C. Calif. Ida. Submont. Mont. 

 Mr-Jl. 



39. DRABA L. WHITLOW GRASS, DRABA. 



Annual or perennial herbs, mostly low, often with stellate or branched pubes- 

 cence. Flowers perfect, in racemes. Sepals equal at the base. Petals yellow 

 or white, longer than the sepals. Pods elliptic to linear, flat; valves nerveless; 

 stigma capitate. Seeds in 2 rows in each cell, neither margined nor winged. 

 Cotyledons usually accumbent. 



Winter annuals. 



Style slender, 12 mm. long; filaments dilated. 1. D. asprella. 



Style obsolete. 

 Pods hairy. 



Leaves all crowded on the lower part of the stem; flowers white; racemes short, 



on long naked peduncles. 

 Pods linear, appressed-hirsute; leaves entire. 



Inflorescence even in fruit corymbiform; petals minute or none. 



2. D. micrantha. 

 Inflorescence in fruit elongate; petals conspicuous. 



3. D. coloradensis. 

 Pods oblong or elliptic, with spreading branched pubescence, often stellate; 



leaves usually toothed. 4. D. cuneifoliq. 



Leaves more or less scattered on the stem; flowers yellow or in age sometimes 



white. 

 Basal leaves obovate, ovate, or oblong; stem-leaves ample; pedicels longer 



than the pods. 5. D. nemorosa. 



Basal leaves oblanceolate to oblong; stem-leaves smaller, oblong-lanceolate; 



pedicels shorter than the pods. 



Pedicels divergent; leaves hirsute. 6. D. montana. 



Pedicels ascending; leaves stellate, not hirsute. 7. D. praealta. 



Pods glabrous. 



Pedicels in fruit reflexed; petals white. 8. D. deflexa. 



Pedicels ascending or spreading; petals yellow. 

 Stem more or less leafy. 



Pods 2-4 mm. long; stem-leaves thick. 9. D. brachycarpa. 



Pods 68 mm. long; leaves thin. 



Basal leaves obovate; stem-leaves several, broad; pedicels twice 



as long as the pod. 10. D. lutea. 



Basal leaves oblanceolate; stem-leaves very few and small; pedicels 



slightly, if at all, longer than the pod. 11. D. nitida. 



Stem scapiform or with a single leaf; leaves in a basal rosette. 

 Basal leaves spatulate; pods more than 1 cm. long. 



Basal leaves broadly spatulate, finely stellate; petals white. 



12. D. Macouniana. 

 Basal leaves spatulate, but not broadly so, hirsute as well as stellate; 



petals yellow. (Depauperate forms of) 11. D. nitida. 



Basal leaves oblanceolate to linear, hirsute or glabrate; pods 5-8 mm. 



long. 



Basal leaves oblanceolate or spatulate, hirsute. 13. D. crassifolia. 

 Basal leaves narrowly linear-oblanceolate, glabrous, except the very 



sparingly ciliate margins. 14. D. Parry i. 



Perennials; style usually evident. 

 Plants scapose or nearly so. 



Pod 16-20 mm. long and 7-8 mm. wide. 15. D. eurycarpa. 



Pod less than 12 mm. long and 5 mm. wide. 

 Petals yellow. 



Pods about twice as long as broad, 512 mm. long. 

 Pods glabrous or nearly so. 



Leaves not stellate, glabrous, except the ciliate margin. (Depauperate 

 variety of) 41. D. streptocarpa. 



Leaves more or less stellate over the whole surface. 



Leaves broadly spatulate, long-ciliate, especially on the margin; 



midrib weak. 16. D. alpina. 



Leaves linear-oblanceolate, scarcely ciliate; midrib strong. 



17. D. glacialis. 

 Pods pubescent. 



Leaves obovate, densely and finely white-stellate ; midrib indistinct. 



18. D. argyrea. 

 Leaves spatulate or linear-oblong, sparingly stellate, with a strong 



midrib. 



Plant cespitose, but not densely pulvinate; leaves oblanceolate 

 or spatulate, rather finely stellate, spreading, not densely 

 imbricate. 19. D. incerta. 



