CRASSULACE^ 113 



land, Jura, Pyrenees. .S. altissimum^ Poirr. ; flowers very 

 pale yellow, stem somewhat shrubby, branched, leaves 

 oval, concave above ; Pyrenees, Dauphiny. 



3. Sempervivum, L. 



Flowers large, bisexual, in corymbose or panicled cymes ; 

 calyx-teeth and petals 6 or more ; stamens usually twice 

 as many as petals ; carpels as many as petals ; leaves 

 fleshy, often covered with arachnoid hairs. All the 

 species are alpine, and the genus is especially character- 

 istic of the mountains of Switzerland and Tirol. The 

 species are often difficult to distinguish, and appear to 

 hybridise readily. 



A. Calyx -teeth, petals, and carpels more than 6; 

 rosette-leaves ciHate at the margin, otherwise glabrous : 

 — vS. Wulfeni, Hoppe ; petals yellow or whitish, leaves 

 glaucous, stem and calyx covered with rough glandular 

 hairs; rare; Engadine, Tirol, Styria, Carniola. 6". al- 

 pinum, G. and S. {Boutignianum, G. and G.) ; petals 

 linear-lanceolate, three times as long as calyx-teeth, 

 ciliate, red with a darker central streak, marginal hairs 

 of rosette-leaves not glandular ; rare ; Engadine, Ticino, 

 Tirol, Pyrenees. vS. tectorum^ L., House-Leek; petals 

 lanceolate, twice as long as calyx-teeth, pink, rosettes 

 large, rosette-leaves suddenly contracted into a point, 

 which is usually red, stem-leaves acuminate; rocks; 

 Switzerland, Tirol, Pyrenees ; also in the lowlands cul- 

 tivated on roofs, &c. 6". acuminatum, Schott; similar 

 to the last, but rosette-leaves gradually acuminate, leaves 

 bluish-grey ; Tirol, rare (Botzen). 5. arvenense, L. and 



L. ; flowers pink, half the size of the last, petals ij 

 VOL. I. H 



