FLORA. 



Rapfstrum rugbsum (L.) All., a plant with 2-jointed indehiscent pods, erect on 

 appressed pedicels, in long racemes, has been found as a waif at Easton, Penn., and 

 plentifully in ballast about the seaports. It is nearly related to Raphanus. 



30 DRABA L. 



Low tufted mostly stellate-pubescent herbs, with simple leaves, and mainly 

 racemose flowers. Silicles elliptic, oblong or linear, flat, few to many-seeded. 

 Stigma nearly entire. Seeds wingless, in 2 rows in each cell of the pod, numer- 

 ous; valves dehiscent, nerveless; cotyledons accumbent. [Greek name for some 

 plant of this family.] Species about 150, mainly natives of temperate and arctic 

 regions. Besides the following, some 25 others occur in western N. Am. 



Flowers white or whitish. 



Petals deeply 2-cleft. I. D. verna. 



Petals entire, toothed, or emarginate. 



Flowering stems scapose, leafy only below. 

 Plants annual, not arctic. 



Leaves entire, obovate or oblong. 2. Z>. Caroliniana. 



Leaves dentate, cuneate to spatulate. 3. D. cuneifolta. 



Low arctic perennials. 



Leaves pilose-ciliate or glabrous. 4. D. Fladnizensis. 



Leaves stellate canescent. 5. D. ntva/ts. 



Flowering stems leafy throughout up to the inflorescence. 



Leaves entire or sparingly dentate. 6. D. incana. 



Leaves sharply dentate. 7. D. ramosissima. 



Flowers yellow ; (white in No. 8); stems leafy. 



Pods oblong, 2-4 mm. long. 8. D. brachycarpa. 



Pods linear or lanceolate, 6-14 mm. long. 



Annual ; pods 6-8 mm. long ; pedicels divaricately spreading. 



9. D. nemorosa. 



Perennial ; pods 8-14 mm. long; pedicels erect. 10. D. aurea. 



Flowers yellow ; stems scapose. n. D. alpina. 



1. Draba verna L. VERNAL WHITLOW-GRASS. (I. F. f. 1755.) Annual, 

 the leafless scapes numerous, 2-13 cm. high, arising from a tuft of basal leaves, 

 which are oblong or spatulate-oblanceolate, 1-2.5 cm - l n g acutish and pubescent 

 with stellate hairs; flowers 3-4 mm. broad; pedicels 1-2.5 cm. long in fruit; pods 

 oblong, glabrous, 6-8 mm. long, 2 mm. broad, obtuse, shorter than their pedicels; 

 style minute; seeds numerous. In fields, common except in the extreme north. 

 Nat. from Europe. Feb. -May. 



2. Draba Caroliniana Walt. CAROLINA WHITLOW-GRASS. (I. F. f. 1756.) 

 Annual; scapes 2-13 cm. high from a short leafy stem. Leaves tufted, obovate, 

 8 -20 mm. long, obtuse, entire or rarely with 3 or 4 teeth, pubescent with stellate 

 hairs; scapes nearly glabrous ; flowers 3-4 mm. broad ; petals entire, sometimes 

 wanting in the later flowers; pedicels 2-4 mm. long in fruit; pods linear, 8-12 mm. 

 long, nearly 2 mm. broad, glabrous; style none. In sandy fields, Mass, to Ont., 

 Minn., Neb., Ga. and Ark. March-June. 



Draba Caroliniana micrlntha (Nutt.) A. Gray. Differs from the type in the ap- 

 pressed- hispid pods. Petals often wanting. Prairies, 111. to Tex., N. Mex. and Wash. 



3. Draba cuneifolia Nutt. WEDGE LEAVED WHITLOW-GRASS. (I. F. f. 1757.) 

 Annual, stellate -pubescent, 1-2 dm. high, branching and leafy below. Leaves 

 obovate, cuneate, or the lowest spatulate, 1-4 cm. long, obtuse, dentate toward the 

 apex ; flowers 4 mm. broad ; petals emarginate, twice or thrice the length of the 

 calyx; pedicels ascending or spreading, 4-8 mm. long in fruit; pods linear-oblong, 

 ob'use, 8-10 mm. long, 2 mm. wide, minutely hairy; style none. In fields, Ky. 

 to Kans., Fla. and Cal. Feb. -April. 



4. Draba Fladnizensis Wulf. WHITE ARCTIC WHITLOW-GRASS. (I. F. f. 

 1758.) Tufted. Leaves oblanceolate, basal, rosulate, acutish, entire, stellate- 

 ca icscent or with some simple hairs, ciliate or rarely nearly glabrous, 8-16 mm. 

 long; flowers whitish; scapes glabrous; pedicels ascending, 2-4 mm. long in fruit; 

 pods oblong, glabrous, 4-6 mm. long, nearly 2 mm. wide; style almost wanting. 

 Gaspe, Quebec, and through arctic America, south in the Rocky Mts. to Colo. 

 Also in arctic and alpine Europe and Asia. Summer. 



