SEMPERVIYUM. 



THE ENGLISH FLOWER GARDEN. SEMPERVIVUM. 811 



shady spots in the rock-garden. These 

 kinds are S. denticulata, S. helvetica, and 

 S. rupestris, small trailing plants of a deli- 

 cate green, mossy growth. S. Kraussiana, 

 generally known in plant-houses as S. 

 denticulata, is also hardy in many places, 

 and in Ireland grows and thrives better 

 than any of the kinds mentioned. All 

 these plants require a well-drained peaty 

 soil and shaded and sheltered position. 



SEMPERVIVUM (Houseleek}. Suc- 

 culent Rock and Alpine plants, of which 

 the common Houseleek (S. tectorum), 

 often seen growing in patches on old 

 roofs and walls, is the most familiar. 

 There is a strong family likeness through- 

 out, and they form rosette-like tufts of 

 fleshy leaves, which chiefly differ in the 

 colour of the foliage, some deep red, others 

 pale green. The flowers of most of them 

 are of a reddish tinge, and several are 

 yellow. All the hardy kinds will grow 

 well in dry sandy parts of the rock-garden 

 where few other alpines thrive ; or on old 

 walls, ruins, and the like, merely requiring 

 to be placed in chinks with a little soil. 

 Most of them thrive on any border, if the 

 soil be not too stiff and damp, but they 

 prefer a dry elevated position, and full 

 exposure to the sun. Nearly all are easily 

 increased by offsets, which, as a rule, are 

 abundantly produced. Of late years some 

 of the larger kinds, such as S. calcareum, 

 have been used for beds. Europe and W. 

 Asia. 



S. arachnoideum (Cobweb Houseleek}. 

 One of the most singular of alpine 

 plants, with tiny rosettes of fleshy leaves 

 covered at the top with a thick white down, 

 which intertwines itself all over the leaves 

 like a spider's web. It is rarely seen in 

 our gardens except in a frame, but thrives 

 in moist sandy loam and exposed spots in 

 sunny arid parts of the rock-garden. Its 

 sheets of whitish rosettes look as if a 

 thousand spiders had been at work upon 

 them, and in summer send up pretty rose- 

 coloured flowers. About London it some- 

 times suffers from sparrows plundering 

 the "down." Division. Similar to this 

 species are S. tortuosum (or Webbianum 

 of gardens), S. Fauconneti, S. heterotri- 

 chum, and S. Laggeri, which have the 

 rosettes of leaves united by a web of 

 white threads. 



S. arenarium (Sand Houseleek}. 

 Grown in dense patches, this plant has a 

 lovely effect. It is much smaller than its 

 ally S. globiferum, and, unlike the latter 

 species, the leaves of the rosettes are not 

 incurved. The flowers are small, yellow, 

 pretty, and the leaves usually rich crimson. 

 S. Heufelli, a similar species, has in 



autumn almost chocolate-crimson foliage, 

 the flowers being yellow. Other species 

 of similar character are S. hirtum, S. 

 Neilreichi, and S. soboliferum, which is 

 often confused with S. globiferum. 



S. calcareum (Glaucous Houseleek}. 

 No finer Houseleek has ever been intro- 

 duced than this, sometimes called S. 

 californicum. It is as easily grown and 

 as hardy as the common Houseleek (S. 

 tectorum), and thrives in any soil. 

 Planted singly, its rosettes are sometimes 

 nearly 5 in. across, the leaves glaucous, 

 and tipped at the points with chocolate. 

 It is deservedly popular for edgings in the 

 flower garden and also admirable for the 

 rock-garden. Other cultivated kinds are 

 S. glaucum, S. Camollei, S. Lamottei, S. 

 Verloti, and S. juratense, and these are 

 all desirable for a full collection. 



S. fimbriatum (Fringed Hottseleek}. 



One of the most profusely blooming kinds, 



! the dark rose-coloured flowers appearing 



I in summer on stems 6 to 10 in. high. 



The leaves, which are in small -rosettes, 



are smooth on both sides, strongly fringed, 



j and terminate in a long point, being 



marked at the end with a large purple 



j spot. S. Funcki, S. Powelli, S. barbatu- 



i lum, S. atlanticum, and S. piliferum are 



| similar. 



S. globiferum (Hen-and-chicken House- 

 | leek}. This grows in firm dense tufts, 

 j its little round offsets being so abundantly 

 j thrown off that they are pushed clear 

 above the tufts, and lie on the surface in 

 I small brownish-green balls. The small 

 j leaves of the young rosettes all turn in- 

 i ward and appear of a purplish colour, but 

 ' in the full-grown rosettes are light green, 

 the tips of the under side being of a 

 decided chocolate-brown for nearly one- 

 third of their length ; the flowers are 

 small and yellow. This kind is well- 

 suited for forming wide tufts in the rock- 

 garden, and on banks below the eye. It 

 grows freely in any soil, and is also known 

 as S. soboliferum, but this is the name of 

 another kind similar to S. arenarium. 



S. montanum (Mountain Houseleek}. 

 A dark green kind, smaller than the 

 common Houseleek, the leaves forming 

 neat rosettes, from which spring dull rosy 

 flowers in summer. It is suitable for 

 edgings or for the rock-garden, grows in 

 any soil, and is easily propagated. Alps. 

 S. assimile and S. flagelliforme are 

 similar. 



S. tectorum (Common Houseleek}. 

 Though a native of rocky places in the 

 great mountain ranges of Europe and 

 Asia, the common Houseleek, having been 

 cultivated from time immemorial on house- 



