53G THE GARDENER. [Dec. 



NOTES ON HARDY HERBACEOUS PLANTS. 



(Continued from page 516.) 

 CRASSULACE.E — COlif. 



Sernpervivum — Uouseleek. — This family is possessed of the strongest 

 tenacity of life — the generic name implies that; and it is highly in- 

 teresting on account of the rigidly geometric arrangement in rosettes 

 that the leaves of most of the species take. Their extraordinary 

 power of life renders them very useful for many ornamental purposes 

 that are very desirable, but not by any means generally adopted. 

 Many a stump and block and naked rock might be appropriately 

 garnished with them ; and those objects, often inert enough and unin- 

 teresting in themselves, but from various circumstances, perhaps, irre- 

 movable, would by such adornment become attractive and beautiful ; 

 and quaint old trees and ruins may be enriched in their own style by 

 the same means. The natural habitats of the Houseleeks — house-tops, 

 walls, rocks, and generally dry exposed stony or gravelly places — at 

 once suggest their fitness for the uses indicated. They establish them- 

 selves easily in such places in nature ; and in practice to fix them in any 

 position is a very simple matter, all that is needed to that end 

 being a little clay and horse or cow dung, well mixed, as for use in graft- 

 ing, on which to stick the offshoots, when, even if the surface is vertical, 

 they may be left to themselves without any misgivings as to success. 

 The adaptability of some of the species to another and very different 

 use in flower-gardening has been noticed and taken advantage of by 

 some of our best gardeners recently, and is becoming popular. I 

 allude to the new method of bedding out, in which various Semper- 

 vivums are used to define intricate geometrical figures in beds or bor- 

 ders, the spaces being filled, according to the taste of the parties 

 concerned, with flowering plants, or with plants of different foliage, 

 with a view to the production of contrasts in form or combinations of 

 colour and form ; and for defining with precision intricate lines and 

 figures, there is perhaps nothing in the vegetable kingdom more fit 

 than these peculiar plants ; but for this purpose they must be used in 

 single rosettes, which entails the necessity of their being overhauled 

 annually in spring, so as to remove all off-sets or young rosettes which 

 would mar the lines. They are as easily cultivated on flat surfaces on 

 the ground-level as on any elevation, and though so well adapted to 

 exist on short commons, do equally well in the richest soil, but it is 

 always well to drain well under them. 



S. araehnoideum — Cobweb Houseleek. — An extremely interesting and 

 curious plant. The rosettes are small, composed of oblong sharp- 

 pointed leaves, thickly set on both surfaces with soft, short, glandular 



