106 ALPINE PLANTS 
number of Sedums, a collection can be added to from 
time to time at will. 
SEMPERVIVUM.—Commonly known as “ House Leek,” 
the Sempervivums are succulent plants of cactus-like 
character, so tenacious of life that they will not only 
exist but thrive and look happy even in positions that 
afford them scarcely a root-hold on the rugged ledge of 
a rock with the merest covering of soil. It is no uncommon 
sight to see a colony of Sempervivum tectorum braving 
the scorching sun on the top of an old garden wall or on 
the roof of a shed or country cottage, and whether between 
rough stone edging to a pathway, in the chinks of stone 
steps, or on the steep slopes of a rockery bank, Semper- 
vivums will delight us the whole year round with their grey, 
green, russet, or metallic tinted rosettes, and in due season 
with their quaintly beautiful, waxy-looking flowers of 
starry shape and generally quiet tints. 
In size the rosettes of Sempervivums vary greatly. S. 
globiferum makes many clustering rosettes not much larger 
than peas. S. Regine-Amaliz develops to the extent 
of 4 inches diameter, and S. atro-violaceum grows quite 
as large, the foliage being broad, thick, and of a delightful 
violet-purple shade. The cobweb house leek, S. arachnoi- 
deum, is a general favourite, and quite deservedly so. 
Its globular rosettes of closely-packed leaves have a won- 
derful hair-like thread stretched from tip to tip of every 
leaf, giving the plant an appearance of having been cur- 
tained by some fairy spider, and on a dewy morning the 
effect of glistening globules of moisture on this vegetable 
cobweb is fascinatingly beautiful. The cobweb is always 
