18 CRUCIFERAE 



I. Pods dehiscent by valves. 

 A. Pod a siliquc {lincarcloni/atui to oblong, several times longer than wide). 



Pods on ft long stipo (5 to 10 lines long) ; flowers yellow 1. Stanleya. 



Pods not stipitnto, or on n very sliort or obscure stipo (% to 1 line long). 

 Racemes loafli'ss and l)r;ictiess. 



Pods not beaked or merely tipped with tho persistent style (cf. one sp. in no. 2). 

 Stems from annual or perennial roots or root-crowns. 

 Valves 1- (or more) nerved. 



Seeds in 1 row in each cell (except 2 species in no. 5 and several in no. IG). 

 Flowers yellow, or often white in nos. 4 and 5. 



Leaves dissected or pinnatifid, or some at least lobed ; flowers 

 small. 

 Pods terete. 



Annuals 5. Sisymbrium. 



Perennials 4. Haumolobu.s. 



Pods somewhat quadrangular, pointed; perennial 



11. Barbaeea. 

 Leaves entire or merely dentate, at least not lobed ; flowers large, 



orange or yellowish 17. Erysimum. 



Flowers white or whitish (rarely yellowish) to purple or purplish. 

 Petals with a broad linib, not crisped or twisted. 



Pod teretish ; flowers white or pale yellow ; leaves pinnately 



divided into small segments; tufted perennial 



1.5. Smelowskia. 

 Pods flattened; leaves dentate or entire, a few species pin- 

 nately divided or lobed. 



Pods not horned at apex; seeds winged or wingless 



16. Arabis. 

 Pods 2-horned at apex; seeds winged.. ..18. Matthiola. 

 Petals commonly with narrow limb. 



Sepals mostly greenish; petals white or yellowish, rarely 

 purple or roseate, the blade not crisped; filaments 

 distinct; stigma entire or obscurely 2-lobed; pods 

 terete or nearly so; seeds not winged 



3. THEIiYPODIUM. 



Sepals mostly colored, commonly purple; petals purple or 

 white, rarely yellow, the blade often crisped, often 

 narrower than the claw; filaments distinct or the 

 upper pair connate and sometimes the lower pair; 

 stigma entire to deeply 2-lobed; pods flattened; 



seeds winged or wingless 2. Steeptanthus. 



Seeds in 2 rows in each cell. 



Pods terete; flowers yellow or white 12. Radicula. 



Pods strongly flattened; flowers purplish 19. Parrta- 



Valves not nerved; leaves pinnate 13. Cardamine. 



Stems from tuberous rootstocks, naked below; flowers white 14. Dentaria. 



Pods produced into a beak beyond the valves; embryo with conduplicate cotyledons; 

 flowers yellow; nectar glands 4. 



Pods terete; seeds in one row in each cell 9. Brassica. 



Pods somewhat compressed ; seeds in two rows in each cell 10. Diplotaxis. 



Racemes leafy; leaves pinnatifid; annual 20. Tropidocaupum. 



B. Pod a silicle (globose, orbicular or oblong, about 1 to 3 times as long as wide). 

 Pods not turgid. 



Pods flattened parallel to the broad partition. 

 Flowers in racemes; seeds not winged. 



Pod 1 or 2-seeded; low altitudes 29. Alyssum. 



Pod many-seeded; seeds in 2 rows in each cell; mostly alpine or subalpine 



32. Draba. 



Flowers solitary on naked scapes; seeds with a broad membranous wing 



28. Platyspermum. 

 Pods flattened contrary to the narrow partition. 

 Seeds 2 to several in each cell. 



Herbage glabrous; leaves undivided 24. Thlaspi. 



Herbage pubescent; leaves pinnately incised or parted. 



Flowers white, 1 line long; pods 1 to 4 lines long 30. Capsella. 



Flowers purplish, 6 lines long; pods 3 to 9 lines long 21. Lyrocaepa. 



