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. cunei folia. 



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 6-8 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. nilida. 



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. Parryi. 



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, 5-12 mm. long. 

 Pods glabrous or nearly so. 



Leaves not stellate, glabrous , except the ciliate margin . ( D epauperate 

 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. 



