MUSTARD FAMILY 297 



Leaves crowded, linear, about 5 mm. long, 1 mm. wide, midrib evident, cinereous with 2-4-forked 

 pubescence, the forks stalked, cilia inconspicuous; flowering branches 2-5 cm. long, pubescent; 

 racemes short, few-flowered, somewhat corymbose ; sepals 2 mm. long, pubescent ; petals 3 mm. 

 long, white; pods broadly elliptic, 4 mm. long, 2.5 mm. wide, flattened, pubescent or glabrous; 

 style 0.75 mm. long; seeds not winged. 



Alpine ridges, Hudsonian and Arctic-Alpine Zones; Cascade Mountains, Washington, to the central 

 Sierra Nevada, California, and Blue Mountains, Oregon, east to Montana and Utah. Type locality: Upper 

 Marias Pass, Montana. June-Aug. 



15. Draba Nelsonii Macbride & Payson. Nelson's Draba. Fig. 2079. 



Draba Nelsonii Macbride & Payson, Amer. Journ. Bot. 4: 259. 1917. 



Cespitose perennial, with short caudex branches. Leaves linear, 5-7 mm. long, about 1 mm. 

 wide, obtuse at apex, midvein prominent, strongly ciliate on the margin, otherwise glabrous; 

 scapes slender, glabrous or sparingly pubescent; petals yellow, 3-4 mm. long; raceme elongated 

 in fruit ; pods lanceolate, 3-6 mm. long, compressed, pubescent with simple hairs ; style 1 mm. 

 long ; seeds wingless. 



Rocky alpine slopes, Boreal Zones; eastern Washington and Idaho, south through eastern Oregon to the 

 Sierra Nevada, California. Type locality: "Central chain of the Rockies towards Lewis's River." June-Aug. 



Draba caeruleomontana Payson & St. John, Proc. Biol. Soc. Wash. 43: 119. 1930. Leaves linear or 

 very narrowly oblanceolate, 10-15 mm. long, strongly ciliate on the margin and sparsely so on the prominent 

 midvein, sparsely pubescent toward the apex with forked hairs; scapes 5-15 cm. long, glabrous or sparsely 

 pubescent with simple and forked hairs; fruiting racemes usually elongated and open; pedicels 10—15 mm. 

 long; pods oblong, strongly compressed, 4-7 mm. long, glabrous, or pubescent. Rock crevices, Boreal Zones; 

 Blue Mountains of eastern Washington and Oregon. This species is very close to D. Nelsonii Macbride & 

 Payson, and seems to intergrade with it in northern California. 



16. Draba sphaerula Macbride & Payson. Desert Draba. Fig. 2080. 



Draba sphaerula Macbride & Payson, Amer. Journ. Bot. 4: 258. 1917. 

 Draba globosa var. sphaerula O. E. Schulz, Pflanzenreich 4 106 : 103. 1927. 



Densely cespitose perennial, branches of the caudex short and crowded. Leaves densely 

 imbricated and incurved, forming rounded tufts, linear, about 2 mm. long, less than 1 mm. 

 wide, glabrous except for cilia; scapes scarcely exceeding the leaves, pubescent; petals yellow; 

 fruiting inflorescence corymbose ; pods 1-3, about 3 mm. long, flat, stellate ; style scarcely 1 mm. 

 long. 



Desert mountain ranges, Boreal Zones; Idaho to western Nevada and the White Mountains, California. 

 Type locality: "Parker Mountain, Custer Co., Idaho." June-July. 



17. Draba subsessilis S. Wats. White Mountain Draba. Fig. 2081. 



Draba subsessilis S. Wats. Proc. Amer. Acad. 23: 255. 1888. 



Draba oligosperma var. subsessilis O. E. Schulz, Pflanzenreich 4 105 : 100. 1927. 



Cespitose perennial, the branches of the caudex short. Leaves narrowly oblong, obtuse, 2-3 

 mm. long, densely imbricated, finely silvery stellate ; scapes very short, stellate ; petals white, 

 2 mm. long; fruiting pedicels 2 mm. long; pods ovoid, 4 mm. long; style thick, scarcely 0.5 mm. 

 long. 



Alpine summits, Boreal Zones; White Mountains and central Sierra Nevada (Mount Dana), California. 

 Type locality: altitude 13,000 feet, White Mountains, Mono County, California. June-July. 



18. Draba novolympica Payson & St. John. Olympic Draba. Fig. 2082. 



Draba novolympica Payson & St. John, Proc. Biol. Soc. Wash. 43: 113. 1930. 



Perennial, densely cespitose with many short dichotomous branches densely clothed with the 

 old leaf bases. Leaves linear or narrowly linear-oblanceolate, 3-4 mm. long, incurved, coriaceous, 

 keeled on the back by the prominent midvein, loosely pubescent with forked hairs ; scapes slen- 

 der, villous-pubescent, 1 cm. long or less, 3-8-flowered ; petals yellow, 3-3 . 5 mm. long ; pods 

 ovate-lanceolate, oblique, 2-5 mm. long, pubescent with forked hairs; styles stout, 0.2-0.3 mm. 

 long; seeds 2-6, brown, wingless. 



Rocky mountain ridges, Arctic-Alpine Zone; Olympic and Cascade Mountains, Washington. Type locality: 

 rocky summits, altitude 6,000 feet, Olympic Mountains, Washington. July-Aug. 



19. Draba Douglasii A. Gray. Douglas' Draba. Fig. 2083. 



Draba Douglasii A. Gray, Proc. Amer. Acad. 7 : 328. 1867. 

 Braya oregonensis A. Gray, Proc. Amer. Acad. 17 : 199. 1882. 

 Draba Crockeri Lemmon, Bull. Torrey Club 16: 221. 1889. 



Cespitose perennial, the branches of the caudex very short. Leaves spatulate-linear, 3-6 mm. 

 long, scarcely 2 mm. wide, firm, midvein prominent, weakly ciliate on the margins, sparsely 

 pubescent with simple or obscurely 2-forked hairs, usually soon glabrate ; scapes scarcely ex- 

 ceeding the leaves, pubescent ; raceme 10-15 mm. long ; petals white, 3 mm. long ; pods ovoid, 

 4 mm. long, acuminate, the sides convex ; style slender, 1 . 5-2 mm. long. 



Boreal Zones; Klickitat County, Washington, south through eastern Oregon and the Sierra Nevada to the 

 San Bernardino Mountains, California. Originally collected by Douglas, but definite locality not known. May- 

 June. 



Draba cascad6nsis Payson & St. John, Proc. Biol. Soc. Wash. 43: 111. 1930. Leafy-stemmed perennial, 

 loosely pubescent with forked hairs; fruiting racemes 5-7 cm. long; pods 8-12 mm. long, puberulent with simple 

 and forked hairs. Moist alpine meadows, Glacier Peak, Snohomish County, Washington. 



20. Draba Breweri S. Wats. Brewer's Whitlow-grass. Fig. 2084. 



Draba Breweri S. Wats. Proc. Amer. Acad. 23: 260. 1888. 



Low cespitose perennial, with a much branched densely leafy cushion-like caudex, hoary 



