26 CRUCIFEK.E. 



7. Streptanthus. Anthers elongated, sagittate at base. Petals often without a dilated blade, 



more or less twisted or undulate, the claw channelled. Calyx dilated and usually 

 colored. Seeds in one row. 



8. Cheiranthus. Petals with a broad flat limb and long claw. Calyx large, not colored. 



Seeds in one row, not margined. 



* Pod terete or 4-angled, slightly or not at all compressed : seeds not margined ; cotyledons 



incumbent or more or less oblique. 



+- Pod long-linear (1 to 4 inches) ; valves 1 -nerved : seeds in 1 row, oblong, somewhat flattened ; 

 cotyledons mostly more or less oblique : anthers linear. . Stout biennials or perennials, 

 n- Flowers white to purple : anthers sagittate. 



9. Caulanthus. Petals with a broad claw, somewhat dilated above and undulate, little longer 



than the broad sepals, usually purple. Filaments included. Stigma nearly sessile, some- 

 what 2-lobed. Pod sessile, 3 inches long or more. 



10. Thelypodium. Petals with narrow claw and flat linear to rounded limb, much exceeding 



the narrow sepals, white or rose-color. Filaments often exserted. Style short ; stigma 

 mostly entire. Pod shorter, sessile or short-stipitate. 



n- -H- Flowers yellow. 



11. Stanleya. Pod somewhat terete, long-stipitate. Stigma sessile, entire. Anthers not 



sagittate, spirally coiled. Leaves petioled, entire or pinnatifid. 



12. Erysimum. Pod 4-angled, sessile. Stigma 2-lobed. Anthers sagittate, not coiled. 



Leaves narrow, entire or repandly toothed. 



4- 4- Pod linear, mostly less than an inch long, more or less 4-angled ; valves 1 - 3-nerved : 

 seeds globose to oblong, smaller and less flattened, in one row (except one species of 

 Sisymbrium) : anthers oblong to linear-oblong : flowers yellow (white in Smelowskia) : at 

 least the lower leaves pinnatifid. 



13. Brassica. Pod nearly terete, with a long stout beak. Seed globose ; cotyledons infolding 



the radicle. Anthers long, sagittate. 



14. Barbarea. Pod pointed, somewhat 4-angled. Seeds oblong ; cotyledons nearly accumbent. 



Anthers short, oblong. Leaves lyrately pinnatifid. A smooth marsh perennial. 



15. Sisymbrium. Pod nearly terete, short-pointed or obtuse. Seeds small, oblong ; cotyle- 



dons incumbent. Anthers linear-oblong, sagittate. Mostly annual, often with finely dis- 

 sected leaves. 



16. Smelowskia. Pod short, 4-angled, pointed at each end. Flowers white or pinkish. 



Alpine perennials with narrowly pinnatifid leaves ; otherwise as Sisymbrium. 



4-4-4- Pod oblong-cylindric to globose ; valves strongly convex, nerveless : seeds in 2 rows ; 



cotyledons accumbent. 



17. Nasturtium. Pod oblong or short-linear. Flowers white or yellow. Smooth or somewhat 



hispid. 



18. Vesicaria. Pod ovate to globose. Seed flattened. Flowers yellow. Densely stellate- 



canescent. 



* * * Pod more or less obcompressed, i. e. flattened contrary to the partition, which is narrower 



than the valves : seeds not winged. 



4- Valves 1 -nerved or obtusely carinate, not winged : cells several-seeded : cotyledons incumbent : 

 flowers white (or yellow in Tropidocarpum). 



19. Subularia. Pod ovoid, slightly obcompressed. A dwarf stemless aquatic, smooth, with 



tufted subulate leaves. 



20. Tropidocarpum. Pod linear, often 1 -celled by the disappearance of the narrow partition. 



Slender hirsute annuals with pinnatifid leaves and axillary flowers. 



21. Capsella. Pod obcordate or oblong, much compressed, many-seeded ; valves carinate. 



Nearly smooth annuals. 



4- 4- Valves acutely carinate or winged : cells few- (1 - 5-) seeded : cotyledons accumbent and 

 flowers white (or in Lcpidium cotyledons mostly incumbent and in one species the flowers 

 yellow). 



22. Lyrocarpa. Pod fiddle-shaped, flattened, somewhat acutely carinate ; cells 5-seeded. 



Pubescent annuals. 



23. Thlaspi. Pod cuneate-oblong ; valves sharply carinate ; cells 2-4 seeded. A smooth 



alpine perennial ; leaves entire. 



24. Lepidium, Pod orbicular or obovate, 2-winged at the summit ; cells 1 - 2-seeded. 



4-4-4- Valves inflated, nerveless : cells several-seeded : cotyledons accumbent : flowers yellow. 



