CRUCIFERAE. 121 



scarcely exceeding the sepals; pods orbicular, margined, notched at the apex, 

 minutely pubescent, 3 mm. broad, on spreading pedicels. Introduced and 

 becoming common. 



168. DRABA. 



Low annual or perennial herbs; leaves entire or toothed; 

 flowers white or yellow, mainly in racemes ; pod oval to oblong or 

 linear, compressed parallel to the partition; valves nearly flat, 

 nerveless or faintly nerved ; seeds few to many, in two rows in the 

 cell, wingless. 



Perennials, flowers yellow. D. glacialis. 

 Annuals. 



Flowers yellow. D. nemorosa. 

 Flowers white. 



Petals deeply 2-cleft; pods glabrous. D. verna. 



Petals entire; pods hispid. D. caroliniana. 



Draba glacialis Adams. Perennial with many short clustered leafy 

 branches; leaves linear, entire, ciliate at base, stellate-pubescent, 5-15 mm. 

 long, rigid in age and with a prominent midrib; scapes 5-15 cm. long; flowers 

 yellow; pods ovate or oblong-ovate, acute, pubescent, 2-8 mm. long, on pedicels 

 a little longer. On rock cliffs in the Blue Mountains. 



Draba nemorosa L. Annual, the simple stems 5-40 cm. high, leafy and 

 pubescent below; leaves sessile, oblong or ovate, usually dentate, acutish, 

 1-2 cm. long, stellate-pubescent; raceme loose, 3-many-flowered ; flowers 

 small, 4 mm. broad; petals yellow, notched, a little longer than the villous 

 sepals; pod oblong, acute, appressed-pubescent or glabrous, about 1 cm. long, 

 much shorter than the spreading pedicels. In warm soil in copses. 



Draba verna L. Annual; stems several, leafless, 5-10 cm. high, simple, 

 nearly glabrous; leaves in a rosette, oblong or oval, toothed or entire, obtuse, 

 48 mm. long, pubescent with branched hairs; flowers white, in a loose raceme; 

 petals deeply 2-cleft; pods oblong, glabrous, 4-8 mm. long, shorter than the 

 spreading pedicels. In sandy soil. 



Draba caroliniana micrantha (Nutt.) Gray. Winter annual; stems slender, 

 usually branched, 3-10 cm. high; leaves entire, obovate to oblanceolate, 

 sessile, stellate-hairy, 6-12 mm. long; petals small, often wanting; pods clus- 

 tered in a short raceme, broadly linear, hairy, 6-15 mm. long. In early spring 

 in warm places. 



169. CAMELINA. FALSE FLAX. 



Erect annual herbs; leaves entire, toothed or pinnatifid; 

 flowers small, yellowish; style slender; pod obovoid or pear- 

 shaped, slightly flattened parallel to the partition, many-seeded. 



Camelina microcarpa Andrz. Stems erect, mostly simple, 30-90 cm. tall, 

 hirsute below, glabrous above; leaves lanceolate, acute, sagittate at base, 

 half-clasping, erect, entire or nearly so, stellate-pubescent; flowers pale yellow; 

 pods obovate, 6-8 mm. long, beaked by the persistent style, glabrous, on 

 slender pedicels. In fields, introduced. 



170. PHYSARIA. 



Low spreading tufted perennials with stellate pubescence; 

 sepals oblong or elliptical, short; petals longer, spatulate to 



