26 THE FLORA OF THE ALPS 



as long as the sepals (instead of twice). D. Hoppeana, 

 Rchb. {Zahlbritckneri, Host.) ; Switzerland, Styria, rare ; 

 has a much shorter style and a few leaves on the stem. 

 D. Saziterz, Hoppe, and D. Spitzelii^ Hoppe ; Styria, 

 Tirol, Salzburg; are dwarf forms, about i in. high, with 

 short lanceolate ciHate leaves, the latter covered with 

 spreading hairs. D. cuspidata, Bieb.; Pyrenees; scarcely 

 differs from D. aizoides except in its broader seed-vessel. 

 D. nemorosa, L. ; flowers large, stem-leaves few, with 

 rounded base ; rocky places ; Pyrenees. 



The differences between some of the species in the 

 following sections are but slight, and hybridisation is 

 probably not uncommon. 



B. Flowers white ; radical leaves forming a single 

 rosette : — D. incana, L. ; stem very leafy, petals twice as 

 long as sepals ; rocky, local. D, Thomasii^ Koch ; stem- 

 leaves few, petals not much longer than sepals ; Switzer- 

 land, Tirol, Carinthia, local. 



C. Flowers white ; radical leaves in numerous rosettes ; 

 very csespitose : — D.puinila, Miel. ; stem leafless, scarcely 

 higher than the rosette of leaves ; Salzburg. D, tomeit- 

 tosUy Whlb. ; flowers large, petals emarginate, stem-leaves 

 and leaf-stalk tormentose, leaves cordate, coarsely dentate, 

 silicule ciliate ; dry, local. D.frigida, Saut. {dubta, Sut.) ; 

 stem few-leaved, leaves grey-green on both sides, hairy, 

 silicule glabrous ; dry, local. D. Pacheri, Stur. ; leaves 

 yellowish-green above, entire or coarsely dentate, densely 

 hairy beneath ; Southern Tirol, Carinthia, rare. D. stel- 

 lata, Jacq. ; stem glabrous, stem-leaves dentate, petals 

 with short claw, emarginate, style of silicule long ; Alps. 

 D, niveay Saut. ; stem glabrous, petals snow-white, with 

 long claw, style of silicule very short; Tirol, Carinthia, 



