CRUCIFER^ 29 



Several species of Cress are weeds in cultivated land, 

 viz., the English species, L. ruderale^ L., campestre, 

 Br., and Draba, L. ; also L. graminifolium^ L., with 

 linear-lanceolate stem-leaves; in Southern Switzerland 

 and Pyrenees. 



I Tribe ThLASPIDIE^. — Silicule short, dehiscent, com- 

 ' pressed at right angles to the septum, horizontal ; radicle 

 accumbent; flowers white or lilac. Genera 30-35. 



30. Thlaspi, L. 



Silicule entire or notched ; petals equal ; sepals erect, 

 equal ; filaments without scales. 



A. Flowers lilac, violet, or pink, rarely white; alpine 

 plants: — T. rotundi folium, L. ; siHcule rounded at the 

 apex, radical leaves roundish, stalked, stem-leaves am- 

 plexicaul ; frequent ; Switzerland, Dauphiny. T, corym- 

 bosuvi^ Gay ; a more compact plant with lanceolate radical 



I leaves ; Zermatt. T, cepecefolium^ Koch ; silicule notched 

 at the apex, radical leaves dentate ; Carinthia, Carniola, 

 Tirol. 



B. Flowers white ; the following are alpine plants : — 

 T. alpestre, L. ; with the raceme elongated in fruit, the 

 silicule broadly winged and notched, and leaves nearly 

 entire; Switzerland, Dauphiny, Pyrenees. T. Salisiiy 

 Briigg. ; resembling the last, but with a more branched 

 stem and dentate leaves ; Switzerland, Tirol. T. alpinuniy 

 Crntz. ; growing in loose tufts, the silicule narrowly 

 winged and scarcely notched, stem - leaves cordate ; 

 pastures ; generally distributed. T, Mureti^ Gremli ; re- 

 sembling the last, but with longer stamens. T. mon~ 

 tanum, L. ; with larger flowers and obcordate broadly 



