CRUCIFERAE. 173 



Cardamine oligosperma Nutt. Annual, erect, usually simple-stemmed, 

 15-30 cm. high, sparsely hirsute throughout or nearly glabrous; leaflets small, 

 orbicular, petiolulate, 3-5-lobed or toothed; raceme few-flowered; flowers 2 

 mm. long; pods erect, 8-20-seeded, 12-20 mm. long. 



Very common in moist upland soil in open woods. 



Cardamine pennsylvanica Muhl. Annual or biennial, glabrous or nearly 

 so, 30-60 cm. high, simple or branched; leaflets 7-13, sessile, mostly oblong, 

 but those of the lowermost leaves suborbicular; pods suberect on spreading 

 pedicels. 



In wet places, common. Ambiguous forms seem to connect with C. oli- 

 gosperma. 



223. THELYPODIUM. 



Stout biennial herbs, often succulent; leaves simple, entire, 

 toothed or pinnatifid, often auricled at the base; flowers usually 

 in rather dense racemes; sepals oblong to linear, rather short; 

 style short ; stigma entire ; pods slender, terete or 4-angled ; seeds 

 oblong, in 1 row in each cell. 



Thelypodium lasiophyllum (Hook. & Arn.) Greene. Annual, erect, 30-90 

 cm. high, hispid below, glabrous above; leaves oblong to oblanceolate, 5-15 

 cm. long, irregularly dentate or incised, the spreading lobes entire or dentate, 

 the cauline sessile; flowers in a close usually simple raceme; petals cream- 

 colored, often purple-tinged, spatulate, 5 mm. long, twice as long as the oblong 

 sepals; pods slender, usually curved downwards, attenuate at apex, 5-7 cm. 

 long. 



Sandy or rocky soil; rare in our limits. 



224. HESPERIS. 



Erect perennial or biennial herbs with some branched hairs; 

 flowers large, showy, pink-purple (in ours) ; sepals erect, oblong, 

 the lateral ones saccate at base; petals with long and slender 

 claws and broad obovate to orbicular blades; pods very long, 

 spreading, torulose, beaked. 



Hesperis matronalis L. Rocket. Perennial herb, the numerous stems 

 erect, 30-90 cm. high; leaves broadly lanceolate, serrate, acuminate, 5-10 cm. 

 long, the lower ones long-petioled; flowers pink-purple; pods slender, spreading, 

 5-10 cm. long. 



A common garden plant, occasionally found escaped from cultivation. 



225. ERYSIMUM. 



Biennial or perennial herbs; leaves rather narrow, entire or 

 toothed, not clasping; flowers often large, usually yellow; pod 

 linear, 4-angled or rarely flattened, not stipitate; valves keeled 

 by the prominent midrib; seeds oblong, marginless, in one row 

 in each cell. 



Pods flattened. E. arenicola. 

 Pods terete. 



Seeds quadrangular. E. asperum. 



Seeds lenticular. E. capitatum. 



