Draba

Draba (Greek, acrid, from the taste of the lvs.). Cruciferas. Whitlow Grass. One of the most important groups of spring-flowering plants for the alpine garden. It is a large and widely scattered genus of tufted, hardy herbs, with stellate hairs: lvs. often in a rosette, mostly uncut: scapes or stems leafy or not: racemes short or long: fls. without bracts, small, white, yellow, rosy or purple.

Drabas are very pretty, dwarf, compact alpine plants, with small but numerous fls.; admirably adapted for the rockery or front part of a sunny border. They require a sunny position and an open soil. It is important that they be well matured by the autumn sun. The plant forms a dense little rosette of lvs., and has a neat appearance at all times. In spring, Drabas are thickly covered with their little fls., and when planted in masses are decidedly effective. Prop. chiefly by division; also by seed, which may be sown in the fall if desired.

Cult. by J. B. Keller.

Of the species described below, only the first, second, fourth and sixth are advertised in Amer. at present. The rest are worth introduction, and can be procured abroad under their names or synonyms.

A. Flowers yellow.
B. Lvs. rigid, keeled, ciliate.
C. Scope not hairy.
D. Style as long as the pod is wide.

aisoides, Linn. About 2-3 in. high: lvs. lanceolate-linear: stamens nearly as long as the petals. March. Eu. B.M. 170.

DD. Style half as long as the pod is wide.

Aizoon, Wahl. About 3 in. high : lvs. linear. April. Europe.

CC. Scape hairy (villous or pubescent).
D. Pod lanceolate, bristly.

cuspidata, Bieb. Lvs. linear: style a little shorter than the pod. Asia Minor.

DD. Pod oval, pubescent.

Olympica, Sibth. (D. bruniaefolia, Stev.). About 4 in. high: lvs. linear, a trifle heeled: petals twice as long as the calyx and stamens: style very short. June. Greece, Orient.

BB. Lvs. not rigid or keeled.
C. Scope not hairy.

hispida, Willd. (D. tridentata, DC.). About 3 in. high: lvs. obovate, narrowed into a long petiole, obscurely 3-toothed at the apex, somewhat bristly: pods oblong, not hairy. Scotland, Caucasus.

CC. Scape more or less hairy.
D. Hairs long, soft and slender, i.e., pilose.

alpina, Linn. Lvs. lanceolate, flat: pods oblong: style very short. April. Arctic regions.

DD. Hairs short, soft and downy, i.e.,pubescent.

aurea, Vahl. Doubtfully perennial or biennial: lvs, ovate-lanceolate, entire or remotely serrate: pods oblong-lanceolate. Arctic regions. B.M. 2934. 

AA. Flowers white.
B. Plants biennial or annual.

cinerea, Adams. Lvs. oblong-linear: pods oblong, pubescent. shorter than the pedicel. Early spring. Siberia. —Closely related to D. confusa. but has a looser, weaker, less leafy stem, the stem-lvs. 5-6, scattered, entire.

BB. Plants perennial.
C. Leaves rigid.