CRASSULACE-SO. 



299 



appressed or spreading leaves of the barren shoots, are very difficult to 

 appreciate, and appear to depend more on station than on any real dif- 

 ference in the plants. 



IV. HOUSSLEEK. SEMPEEVIVUM. 



Succulent herbs, with a perennial, often woody stock, usually larger 

 and coarser than the Sedums ; the thick, succulent leaves densely im- 

 bricated on tlfe short, often globular, barren shoots, and scattered 

 along the erect flowering stems. Inflorescence and flowers as in Sedum, 

 except that the parts of the flower are much more numerous, the sepals, 

 petals, and carpels varying from 6 to 20 (usually 10 to 12). Stamens 

 twice as many, but one half occasionally abortive and very small, or 

 sometimes transformed into extra carpels. The little scales placed 

 under the carpels are toothed or jagged, or sometimes wanting. 



Eesides the common one, there are a few allied species in central and 

 southern Europe, some half-shrubby ones in the Canary Islands, and 

 several in south-western Africa. Some of these have long been in cul- 

 tivation among our garden succulent plants. 



1. Common Houseleek. Sempervivum tectorum, Linn. 

 (Fig. 367.) 



(Eng. Bot. t. 1320.) 



The barren shoots form numerous, 

 almost globular tufts, from whence, in 

 subsequent years, arise the stout, suc- 

 culent flowering stems to the height of 

 about a foot. Leaves very thick and 

 fleshy ; the lower ones 1 to 1 J inches 

 long, ending in a short point, and 

 bordered by a line of short, stiff hairs ; 

 the upper ones as well as the cymes 

 more or less clothed with a short, viscid 

 down. Elowers pink, sessile along the 

 spreading or recurved branches of the 

 cyme. Petals linear, pointed, two or 

 three times as long as the sepals, downy 

 on the outside, and ciliate on the edges, 

 like the leaves. 



In rocky situations, in the great moun- 

 tain-ranges of central and southern Eu- Fig. 367. 



2 a 2 



