CRUCiFERAE (MUSTARD FAMILY^ 



421 



Artificial Key to Genera 



'r. Petals present, with yellow blade and yellowish or whitish claw b. 

 6. Fruit short, not more than 3 times as long as broad. 

 Pubescence stellate. 

 Pods thick. 

 Pods grlobose. 



Pods dehiscent 5. Lebquerella. 



Pods indehiscent 12. Neslia. 



Pods obovoid 11. Camklina. 



Poda thin. 



Pods orbicular 4. Alyssum. 



Pods oblong- , . . 1. Dkaba. ' 



Pubescence simple or none. 



Pods subg-lobose or cylindrical 28. Eadicula. 



Pods very flat and thin 25. Selenia. 



6. Fruit much more than 3 times as long as broad. 



Pods 1-celled or with spongy cross partitions 14. Eapiianus. 



Pods longitudinally 2-celled. 



Seeds 2-ro wed in each cell 16. Diplotaxis. 



Seeds 1-rowed in each cell. 

 Petals 7-15 mm. long. 



Pods thickish, 2-6 mm. in diameter 15. Bbassioa. 



Pods linear, about 1 mm. in diameter 19. Sisymbrium 



Petals smaller. 

 Stem-hairs vertical, attached by the middle, appressed . . 22. Erysimum. 

 Stem-hairs (if present) otherwise. 

 Stem-leaves lanceolate, sessile, subentire ; stem villous at 



base 31. Ababis. 



Stem-leaves elliptical, sessile, entire ; stem glabrous . . 17. Oonringta. 

 Stem-leaves petiolate, toothed or pinnate. 



Leaves bipinnatifid 19. Sibymbeium. 



Leaves simple or pinnatifid. 

 Pods awl-shaped, tapering, closely appressed . . 19. Sisymbrium. 

 Pods linear, cylindrical or compressed. 



Pods (when ripe) 2-5 cm, long 24. Baebarea. 



Pods (when ripe) 7-9 cm. long 19. Sisymbrium. 



1, Petals (when present) with blade white or purplish (sometimes yellow 

 at the base) c. 



c. Peduncles l-flowered, radical i. , , 28. LBAVENwoRTHLt 



c. Peduncles several-flowered, not radical d. 



d. Dwarf aquatic with awl-shaped entire leaves 9. Subulaeia. 



d. Otherwise e. 



e. Fruit transversely 2-celIed ; plant fleshy 18. Cakile. 



6. Fruit longitudinally 2-celIed /. 

 /. Pods short, rarely 3 times as long as wide g. 

 g. Pods compressed contrary to a narrow partition. 



Carpels thicltish, tuberculate-crested or deeply wrinkled . 8. Coronopus. 

 Carpels compressed, smoothish. 

 Pods wedge-shaped at the base; some or all of the hairs 



branched 10. Capsblla. 



Pods not wedge-shaped at the base ; hairs simple or none. 



Seeds several in each cell .6. Thlabpi. 



Seeds solitary in each cell 7. Lepidium. 



g. Pods compressed (if at all) parallel to the broadish partition. 



Pods 2-3 cm. broad 27. Lunaria. 



Pods narrower. 



Hairs none or all simple 23. Radicula. 



Hairs at least in part branched or attached by the middle. 

 Hairs vertically 2-forked, appressed, apparently attached 



by the middle 3. Lobulaeia, 



Hairs otherwise. 

 Seeds 2 in each cell ; pods orbicular .... 4. Altssum. 

 Seeds several to many in each cell. , 4 



Petals deeply bifid. 



Scapose, 1 dm. or less high 1. Draba. 



Leafy-stemmed. 8-8 dm. high , . , . 2. Bekteeoa. 



Petals nearly or quite entire 1. Draba. 



/*. Pods 4-00 times as long as wide A. 

 h. Hairs simple or none. 



Leaves palmately divided 29. Dentaeia. 



Leaves otherwise. 



Fruit thickish, 4-7 mm. in diameter 14. Eaphanus. 



Fruit slender, 1-3 mm. in diameter. 

 Petals purple or rose-colored. 

 Lateral sepals with a hump (often tufted) just below 



the summit 26. Iodanthub. 



Lateral sepals unappendaged 80. Cardamine 



