CRUCIFER^ 79 



Draba L. 



Small annuals or perennials, usually hairy or hoary, with spread- 

 ing or tufted radical leaves, entire or toothed, with few or no stem- 

 leaves. Flowers white or yellow. Filaments of the stamens without 

 appendages. Pod oblong or elliptical, more or less flattened ; the 

 partition broad ; the valves flat or convex. Seeds several in each 

 cell. They mostly differ from Alyssum in their longer pod. 



A considerable genus, ranging over the northern hemisphere, 

 ascending to the highest elevations and to high Arctic latitudes ; 

 and extending along the great mountain chain of America into the 

 southern hemisphere. 



Draba aizoides L. 



Stem erect, 1-4 inches high, simple, glabrous, leafless. Leaves 

 in a radical rosette, linear or linear-lanceolate, acute, entire, 

 ciliated, with long stiff bristles, otherwise glabrous, shining. 

 Flowers bright yellow. Petals sUghtly emarginate. SUicule oval, 

 elliptical, or lanceolate, usually glabrous, surmounted by a long 

 style. 



Limestone rocks and debris, descending to stony places in the 

 lower mountains and hills. May to August, according to altitude. 

 Few plants have so wide a range of altitude. The writer has seen it 

 at various heights from 2000 feet in Haute-Savoie to about 11,000 

 on the Diablons in Switzerland. In England it grows at sea-level 

 in Glamorgan, where it was probably introduced. 



Distribution. — Eastern, Central, and Western Alps, Carpathians, 

 Var, Pyrenees, Corbieres, Cevennes, Jura. 



The variety montana Koch, which is frequent in the Jura, is 

 distinguished by its robust habit and its oblong head of golden 

 yellow flowers, few in number. 



The variety Hoppeana Reichb. {D. Zahlbruckneri Host.) is a 

 small dwarf form found on the higher mountains. It has a style 

 much shorter than the diameter of the silicule. 



Draba nemorosa L. 



Annual. Stem erect, simple, hairy and leafy below, glabrous and 

 naked above. Leaves oval, entire or toothed ; stem-leaves sessile, 

 close together, not auricled. Flowers yellowish, small. Petals 

 emarginate. Fruiting-spike elongated, loose, with spreading 

 pedicels 2 or 3 times the length of the siHcules, which are oblong and 

 pubescent. Style almost wanting. 



Woods and screes in the mountains. May to July. 



Distribution. — Savoy, Eastern Pyrenees, Caucasus. Europe from 

 Spain to Scandinavia ; Asia, N. America. 



