MUSTARD FAMILY 355 



32. D. lonchocarpa Rydb. Densely cespitose perennial; leaves basal, 

 numerous, spatulate, 3-5 mm. long, densely stellate; petals white, 2-2.5 mm. 

 long, obovate; scape 1-10 cm. long; pedicels almost erect; pod linear, 1-1.5 cm. 

 long, 1.5 mm. wide, usually more or less twisted. D. laevipes Hook., not DC. 

 D. nivalis elongata S. Wats. Alpine regions in wet places: Alta. — Mont.— -Wash. 

 —B.C. Subalp.—Alp. My-Jl. 



33. D. fladnizensis Wulfen. Cespitose acaulescent perennial; leaves spatu- 

 late or oblanceolate, 1 cm. or less long, rosulate, hirsute-ciliate on the mar- 

 gins or nearly glabrous; peduncles 1-5 cm. long; petals white, 3 mm. long; 

 pod oblong, glabroiis, 4-5 mm. long, 2 mm. wide. Alpine-arctic situations: 

 Greenl. — Que.— Colo. — Utah — -B.C.; Eu. Subalp. — Alp. Jl-Au. 



34. D. oreibata Macbr. & Payson. Cespitose perennial; leaves oblong- 

 linear, obtuse, 4-6 mm. long, ciliate on the margins, the midvein evident; petals 

 white; fruiting raceme elongate; pod narrowly elliptic, 8-10 mm. long, 2-3 mm. 

 broad; style slender, 1 mm. long. Alpine summits: Ida. — Utah. Subalp. — 

 Alp. My-Jl. 



35. D. cana Rydb. Perennial, with a taproot and short caudex, densely 

 grayish stellate; stem 1-2 dm. high; basal leaves numerous, oblanceolate or 

 spatulate, 1-1.5 cm. long, densely stellate; stem-leaves lanceolate to ovate, 

 about 1 cm. long; pedicels short, nearly erect; petals white, about 3 mm. long; 

 pod linear-oblong, 6-8 mm. long, densely pubescent. D. valida Goodding. Foot- 

 hills and mountains: Alta. — N.M. — B.C. Submont. — Mont. Je-Jl. 



36. D. McCallae Rydb. Perennial with a cespitose base, sparingly stellate 

 but green; stems several, simple, about 3 dm. high; basal leaves spatulate, 10-18 

 mm. long, entire or nearly so; stem-leaves ovate, sharplj^ dentate or entire; 

 pedicels in fruit erect; petals white, 4-5 mm. long; pod ovate, densely but finely 

 pubescent. Along brooks: Alta. Mont. Au. 



37. D. Columbiana Rydb. Perennial, with a cespitose base, sparingly and 

 finely stellate; stems slender, about 2 dm. high, simple; basal leaves many, cil- 

 iate on the margin, oblanceolate, 10-15 mm. long, denticulate or entire; stem- 

 leaves ovate to lanceolate; raceme elongate; pedicels ascending; petals slightly 

 over 2 mm. long, white; pods linear-oblong, finely pubescent, over 1 cm. long. 

 Along rivers, in the moimtains: B.C. — ^Yukon. Subalp. My-Jl. 



38. D. chrysantha S. Wats. Cespitose perennial; stems decumbent, 5-15 

 cm. high, few-flowered; basal leaves narrowly oblanceolate, 2-6 cm. long, entire, 

 ciliate, thin; stem-leaves small; petals 4 mm. long; pods glabrous, 8-12 mm. 

 long; style slender, 1 mm. long. Mountains: Colo.— N.M. — Ariz. Submont. — 

 Subalp. Au. 



39. D. graminea Greene. Cespitose perennial; stem 1 dm. or less high; 

 lower leaves numerous, narrowly linear, ciliate, 5 cm. long, 1 mm. wide; stem- 

 leaves few; petals pale yellow, 4 mm. long; pod glabrous, 7 mm. long, 3 mm. 

 wide. High mountains: Colo. Mont. — Subalp. Jl. 



40. D. crassa Rydb. Cespitose perennial; stems ascending or decimibent, 

 5-15 cm. high, sparingly pubescent; basal leaves 2-4 cm. long, rather thick, 

 generally entire, sparingly ciliate; stem-leaves similar, smaller; petals yellow, 

 3-5 mm. long; pod ovate-oblong, 8-10 mm. long, about 4 mm. wide; style 1 mm. 

 long. High mountains: Mont. — Colo. Mont. —Subalp. Jl-Au. 



41. D. streptocarpa A. Gray. Perennial, with a densely cespitose caudex; 

 gtems more or less hirsute, 1-20 cm. high, leafy; basal leaves oblanceolate; 

 stem-leaves lanceolate or oblong; inflorescence often branched; pedicels erect, 

 8-10 mm. long; petals yellow, 5-6 mm. long; pod lance-linear, about 1 cm. long, 

 2 mm. wide, glabrous, usuallv twisted; style 1.5-2 mm. long. Mountains: Colo. 

 — N.M. Submont. — Alp. 



42. D. spectabilis Greene. Cespitose perennial; stems leafy, 1.5-3 dm. high; 

 basal leaves obovate or spatulate, 2-3 cm. long, rather sparingly stellate; stem- 

 leaves ovate, thin; petals 6-8 mm. long, spatulate, golden yellow; fruiting pedi- 

 cels ascending or spreading, about 1.5 cm. long; pod 8-10 mm. long, glabrous or 

 hirtellous, 2-2.5 mm. wide. Mountains: Colo. — Wyo. Mo7it. — Subalp. Je-Jl. 



