286 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Siliques beaked; seeds globose....... 14. Brassica (p. 301). 
Siliques beakless; seeds oblong. 
Valves of the pods nerveless.... 9. Roripa (p. 296). 
Valves of the pods nerved. 
Annuals; leaves pinnate or 
pinnatifid ...2. 22.222... 15. SisyMBrium (p. 301). 
Perennials. 
Leaves entire or suben- 
tire... 22.2 eee ee. 16. SCHOENOCRAMBE( p. 303). 
Leaves lyrate. 2.2... 17.Campe (p. 303). 
Pods short, therefore silicles. 
Silicles compressed parallel to the partition. 
Flowers solitary on scapes, white; seeds winged. 1. PLATYSPERMUM (p. 286). 
Flowers racemose; seeds wingless. 
Silicles orbieular.. 2.22.22. 2022022022... 2. ALYSsSUM (p. 287). 
vee eee eee eee 3. DRABA (p, 287). 
Silicles not compressed, or compressed contrary to 
the partition. 
Silicles ovate or oblong 
Plant aquatic, submerged; leaves subulate; pods 
subglobose... 2.22.22... 222 2 ee eee 18. SUBULARIA (p. 303). 
Plants terrestrial; leaves not subulate. 
Pods terete, not compressed. 
Pubescence stellate; pods globose... . 10. LESQUERELLA (p. 298). 
Pubescence not stellate; pods oblong. 9. Roripa (p. 296). 
Pods compressed contrary to the partition. 
Valves nerveless; pod obcordate..... 24. PuysarRtia (p. 306). 
Valves 1-nerved. 
Nerves of the valves obtuse, not 
prominent. 
Silicles cuneate, notched at 
~ 
apex ..............-.... 19. Bursa (p. 303). 
Silicles not cuneate; not 
notched at apex. 
Cauline leaves — sessile; 
pod elliptic -...-.-.. 20. Hurcuinsta (p. 304). 
Cauline leaves auricu- 
late; pod obovoid _.. 21. CAMELINA (p. 304). 
Nerves of the valves forming 
acute keels or wings. 
Silicles orbicular or obovate; 
cells 1 or 2-seeded._..-. - 22. Lepipium (p. 304). 
Silicles ovate or oblong; sili- 
cles 2 to several seeded... 28. TuLaspr (p. 305). 
PLATYSPERMUM. 
1. Platyspermum scapigerum Hook. F]. Bor. Am. 1: 68. 1830. 
Type Locauity: ‘Moist rocks and in shallow soil at the Great Falls [Celilo Falls] of the 
Columbia.”” Collected by Douglas. . 
Rance: Washington and Idaho to Nevada. 
SPECIMENS EXAMINED: Klickitat Valley, Howell; Colville, Lyall, March 31, 1861; Pull- 
man, Elmer 82; Piper, April, 1894, May, 1893. 
ZONAL DISTRIBUTION: Arid Transition. 
The stamens in this plant are variable in number, not uncommonly 4 or 5 in place of 
the normal 6. The peppery pods are eaten by children. 
