CRUCIFERAE. 461 



5. Draba nivalis Lilj. YELLOW ARCTIC WHITLOW-GRASS. (I. F. f. 1759.) 

 Perennial by a short caudex; scapes tufted, pubescent, slender, 2-10 cm. high, 

 sometimes bearing a small sessile leaf. Basal leaves oblanceolate or spatulate, 

 4-14 mm. long, entire, acutish or acute at the apex, narrowed into a short petiole, 

 stellate-canescent; flowers about 4mm. broad; calyx pubescent; style short; pods 

 oblong or linear-oblong, narrowed at both ends, glabrous or but little pubescent, on 

 ascending pedicels 2-6 mm. long. Lab. through arctic America to Alaska, south 

 in the Rocky Mts. to Colo., and in the Sierra Nevada to Nev. Also in northern 

 Europe and Asia. Summer. 



6. Draba incana L. HOARY OR TWISTED WHITLOW-GRASS. (I. F. f. 1760.) 

 Perennial or biennial, leafy, stellate-pubescent, 1.53 dm. high. Leaves lanceolate, 

 oblanceolate or ovate, 8-25 mm. long, acutish or obtuse, dentate or nearly entire ; 

 flowers 2-3 mm. broad; petals notched, twice as long as the calyx; pods oblong or 

 lanceolate, acute, twisted when ripe, on short pedicels, densely pubescent or nearly 

 glabrous; style minute. In rocky places, Vt., Quebec to arctic America, Br. 

 Col., south in the Rocky Mts. to Colo. Also in arctic and alpine Europe and Asia. 

 Summer. 



Draba incana ardbisans (Michx.) S. Wats. Stem branched below, bearing tufts of 

 spatulate narrow leaves; pods glabrous, twisted; style i mm. long. Me., Vt., and N. Y. to 

 Lab., west along the Great Lakes to Minn, and Manitoba. 



7. Draba ramosissima Desv. BRANCHING WHITLOW-GRASS. (I. F. f. 1761.) 

 Erect, much branched below, 1.5-3.5 dm. high, stellate-pubescent, the branches 

 bearing tufts of leaves, the inflorescence corymbose-paniculate. Lower leaves 

 spatulate or oblanceolate, 2-5 cm. long, acute, dentate with spreading teeth; upper 

 leaves oblong or ovate, similarly dentate; flowers white, 4-6 mm. broad; petals 

 entire or erose, twice or thrice the length of the sepals; pedicels 6-8 mm. long in 

 fruit; pods oblong or lanceolate, hairy, 6-8 mm. long, twisted; style slender, 2-4 

 mm. long. Mountains of Va., Ky.. N. Car. and Tenn. April-May. 



8. Draba brachycarpa Nutt. SHORT-FRUITED WHITLOW-GRASS. (I. F. f. 

 1762.) Annual, tufted, 4-13 cm. high, loosely stellate-pubescent, leafy. Basal 

 leaves ovate or obovate, 8-12 mm. long, obtuse, sparingly dentate or entire; stem- 

 leaves smaller, sessile, oblong, entire; pedicels 2-4 mm. long in fruit; flowers yel- 

 low, 2 mm. broad ; petals somewhat longer than the calyx, sometimes wanting; 

 pods oblong, acute, 2-4 mm. long, I mm. broad ; style minute. Dry hills and 

 fields, Va. to 111., Kans., Ga. and La. March-May. 



9. Draba nemorosa L. WOOD W T HITLOW-GRASS. (I. F. f. 1763.) Annual, 

 loosely stellate-pubescent, 1.5-3 cm. high, branching below, leafy. Leaves oblong - 

 ovate, or lanceolate, obtuse, sessile, dentate, the lower 1-2.5 cm. long, 1-1.5 cm - 

 wide, the upper smaller; flowers yellow, fading to whitish, 2 mm. broad; petals 

 notched, slightly exceeding the calyx ; pedicels spreading in fruit, glabrous, 6-20 

 mm. long; pods pubescent, or nearly glabrous, oblong, obtuse, 6-8 mm. long; style 

 none. W. Ont., Mich, and Minn, to Ore., arctic Am. and in the Rocky Mts. 

 Also in northern Europe and Asia. Summer. 



10. Draba aurea Vahl. GOLDEN WHITLOW-GRASS. (I. F. f. 1764.) Peren- 

 nial, pubescent with stellate and simple hairs; stem 1.5-2.5 dm. high, leafy. Basal 

 leaves oblanceolate or spatulate, 1-2.5 cm - l n i>' slightly dentate or entire, often 

 ciliate at the base ; stem-leaves oblong or lanceolate, acute; pods lanceolate or ob- 

 long-lanceolate, 8-12 mm. long ; flowers yellow, 4 mm. broad ; petals twice the 

 length of the calyx ; pods acute, pubescent or rarely glabrous, at length slightly 

 twisted, 8-14 mm. long, on erect pedicels; style I mm. long. Mignon Island, Gulf 

 of St. Lawrence, to Greenland ; arctic Am. and in the Rocky Mts. south to Ariz. 

 Summer. 



11. Draba alpina L. ALPINE WHITLOW-GRASS. (I. F. f. 1765.) Perennial 

 by a branched caudex, densely tufted; scapes pubescent, 1-15 cm. high. Leaves 

 basal, entire or few-toothed, oblong, or oblong- lanceolate, mostly narrowed at the 

 base, ciliate, or villous- pubescent, sometimes with some stellate hairs, 4-12 mm. 

 long, sessile or short-petioled ; flowers about 6 mm. broad; calyx pubescent or 

 villous; style I mm. long or less; pod oval or ovate, narrowed at both ends, 5-8 

 mm. long; pedicels 2-10 mm. long. Hudson Bay to Br. Col. and Alaska. Also 

 in northern Europe and Asia. Summer. 



