CKUCIFEKAE 97 



Stellate pubescent. 13. DRABA. 



Not stellate pubescent. 



Stem leaves nearly verticillate. 10. DENTARIA. 



Stem leaves alternate. 



Pods oblong or orbicular. 8. RORIPA. 



Pods long-linear. 9. CARDAMINE. 



Flowers yellow or greenish-white. 

 Pods long-beaked. 



Pods densely hispid. 4. SINAPIS. 



Pods not densely hispid. 5. BRASSICA. 



Pods not long-beaked. 

 Seeds flat. 



Pods 4-angled. 6. BARBAREA. 



Pods not 4-angled. 15. ARABIS. 



Seeds round or oblong. 



Leaves entire, cordate- clasping. 17. CONRINGIA. 



Leaves lanceolate or linear ; not pin- 



natifid. 16. ERYSIMUM. 



Leaves pinnatifid. 



Pubescence of forked hairs. 14. SOPHIA. 



Pubescence, if present, simple. 



Seeds in one row in each cell. 3. SISYMBRIUM. 



Seeds in two rows in each cell. 8. RORIPA. 



1. LEPIDIUM L. PEPPER GRASS. 



Pods roundish to oblong, flattened. Petals often wanting. Cotyledons 

 incumbent or accumbent. 



Petals present, white. 1. L. Virginicum. 



Petals wanting. 2. L. apetalum. 



1. L. Virginicum L. 6 / -24 / high, branching : basal leaves pinnatifid, 

 with large terminal lobe : pods minutely winged above : cotyledons 

 accumbent. Common in waste places. May -July. 



2. L. apetalum Willd. Closely resembles the last, but basal leaves 

 are equally pinnatifid : cotyledons incumbent. Very abundant in waste 

 places. June-August. 



2. THLASPI L. 



Flowers white. Pods oblong- orbicular, flat and winged. Cotyledons 

 accumbent. 



1. T. arvense L. PENNY CKESS. Annual, 6'-2 high : stem leaves 

 oblong-lanceolate, sagittate-clasping, dentate : pods 4 // -6 // broad, deeply 

 notched at the summit. Adventized along Spring Branch east of Inde- 

 pendence. May-June. 



3. SISYMBRIUM L. 



Pods elongated, linear, many-seeded. Valves about 3-nerved. Seeds 

 marginless. Cotyledons incumbent. 



Pods strictly erect, appressed. 1. & officinalt. 



Pods widely spreading. 2. S. altissimum. 



1. S. officinale (L.) Scop. HEDGE MUSTARD. l-3 high: leaves 

 runcinate- pinnatifid : flowers yellow : pods 5 // -7 // long. Abundant in 

 waste places. May-October. 



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