286 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Siliques beaked; seeds globose ,. 14. Brassica (p. 301) . 



Siliquos Ix'aklcss; socds obloii}». 



Valves of the jkkIs nerveless .... 9. Rokipa (p. 296). 

 Valves of the jx)ds nerved. 



Annuals; leaves pinnate or 



pinnatiiid 15. Sisymbrium (p. 301). 



Perennials. 



Leaves entire or suIkmi- 



tiro 10.ScHOENOC'RAMBK(p. 303). 



Leaves lyrato 17. Campe (p. 303). 



Pods .short, therefore silieles. 



Silicle,s compressed parallel to the partition. *" 



Flowers solitary on seajn's, white ; seeds winged . 1 . Pi,atysi'ermiim (p. 286) . 

 Flowers raeenioso: seeds wingless. 



Silieles orbicular 2. Alyssum (p. 287) . 



Silieles ovate or oblong 3. Draba (p. 287) . 



Silieles not compressed, or compressed contrary to 

 the partition. 

 Plant aquatic, submerged; leaves subulate ; pods 



subglobose 18. SuBULARfA (p. 303) . 



Plants terrestrial; leaves not subulate. 

 Pods terete, not compresstnl. 



Puliescence stellate; pods glolK>.se. . . . 10. Lesquerklla (p. 298). 

 Pubo.scenee not stellatt^; jxkIs oblong. 9. Roripa (p. 296). 

 Pods compressed contrary to the partition. 



Valves nerveless; pod obcordate 24. Piiysaria (p. 306). 



Valves 1 -nerved. 



Nerves of the valves obtuse, not 

 prominent. 



Silieles cuneate, notched at 



apex 19. Bursa (p. 303). 



Silieles not cuneate; not 

 notched at apex. 



Cauline leaves sessile; 



pod elliptic 20. Hutciiinsia (p^304). 



Cauline leaves auricu- 



late; pod obovoid 21. Camelina (p. 304). 



Nerves of the valves forming 

 acute keel.-? or wings. 



Silieles orbicular or obovate; 



cells 1 or 2-seeded 22. Lepidium (p. 304). 



Silieles ovate or oblong; sili- 

 eles 2 to several seeded .. . 23. TiiLASPi (p. 305). 



PLATYSPERMUM. 



1. Platyspermum scapigeruiu Ilook. Fl. Bor. Am. 1: 68. 1830. 



Type locality: "Moist rocks and in shallow soil at the Great Falls [Celilo Falls] of the 

 Columbia." Collected by Douglas. 



Range: Washington and Idaho to Nevada. 



Specimens examined: Klickitat Valley, Howell; Colville, Lyall, March 31, 1861; Pull- 

 man, Elmer 82; PiTper, 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. 



