CVI THE HOUSE-LEEK. 
Sempervivum tectorum Linne. 
T here are few more characteristic details in a picture of the English country- 
cottage than the outhouse — be it kitchen, cow-house, or piggery — with its 
tiled roof bearing a rounded cushion of House-leek. This is, however, practically 
the only habitat of the plant in this country, and thus, familiar as it is, it has probably 
little or no claim to be truly indigenous. Possessing a ready means of vegetative 
multiplication, it may grow for years without flowering, the stores of water in its 
rosettes of fleshy leaves preventing its feeling the effects of drought which forces 
many other plants into blossom. That, when it does flower, however, it is a 
strikingly handsome plant, our Plate is sufficient evidence. 
The House-leek (^Sempervivum tectorum Linn6) is a member of a genus of some 
fifty species, natives of the mountains in the central region of the Old World, 
mostly tufted perennial herbaceous plants, but in some cases elongating into 
undershrubs. They produce dense rosettes of simple, fleshy, radical leaves, from 
the axils of which short branches generally originate with other terminal rosettes. 
These offsets, which send out tufts of fibrous roots and may in turn produce other 
offsets like themselves, thus form that cushion-like association which is so 
characteristic of the vegetation of rock-ledges and screes, the chomophytes (from the 
Greek chotna^ earth thrown up) of the ecologists. 
On the dry sunny ledges of the Alps, above the zone of trees and where 
the number of competing species and individuals is comparatively small, various 
species of Sempervivum fix themselves with shallow roots in crevices of shaly rock. 
From such situations the whole colony may be dislodged by the weathering of the 
rock and carried down to lower levels ; or offsets, whilst still small and rootless, may 
be swept by wind or rain from ledge to ledge. Such is the natural habitat of a plant 
which, when in proximity to man, grows almost exclusively on the roofs and walls 
that he has built, so that Linnaeus gave it the appropriate specific name tectorum^ 
i.e. “ belonging to roofs or buildings.” 
It may have been the prevalence of electric storms among the bare alpine peaks, 
on which the House-leeks grow, that first suggested that these plants were proof 
against lightning, so that they became, it is said, sacred to Thor the thunder-god ; 
and the Christian emperor Charlemagne issued an edict ordering that it should be 
planted on every roof. It has, however, been cynically remarked that nowadays at 
least it is more common on the roofs of stables and other farm buildings than on 
those of dwelling-houses, as if the farmer were more solicitous for the safety of his 
cattle than for that of his family. The Early English name Homewort m?iy, however, 
redeem our ancestors from this reproach. 
“ This plant is alwaies greene, neither is it hurte by the colde in winter,” says 
Gerard ; and this evergreen character was alike the origin of most of the names the 
