CRUCIFER^: 23 



14. SlNAPIS, L. 



Seeds in one row; sepals spreading; flowers yellow. 

 Not alpine. 



S. nigra, L., Black Mustard ; S. alba, L., White Mus- 

 tard ; S. arvensis, L., Charlock ; and S. Cheiranthus, 

 M.K., with very deeply divided leaves; are all common 

 weeds in cultivated ground. 



15. DlPLOTAXIS, DC. 



Seeds in two rows ; sepals spreading ; flowers yellow ; 

 leaves pinnatifid. Not alpine. 



D. muralzs, DC., with hispid leafy stem ; D. tenui- 

 folia, L., with much larger flowers ; in waste places. 



1 6. ERUCASTRUM, Pr. 



Seeds in one row; otherwise like Diplotaxis. Not 

 alpine. 



E. obtusangulum, Rchb., with amplexicaul leaves; E. 

 Pollichii, Schp., with smaller pale yellow flowers and 

 leaves not amplexicaul ; and E. incanum, Koch (Hirsch- 



feldia adpressa, Mcench.), with small yellow flowers and 

 short cylindrical seed-vessel, the upper leaves lanceolate, 

 undivided ; are Southern lowland plants. 



17. ERUCA, DC. 



Seeds in two rows; sepals equal at the base; seed- 

 vessel cylindrical ; stigma bilobed. Not alpine. 



E. sativa, Lam. ; flowers dirty-white veined with 

 violet, leaves pinnatifid ; slopes ; Rhone valley. 



