no LETTER XXXVI. 



pated in by a numerous kindred. In Teneriffe, where 

 the genus Sempervivum is very common, the species, 

 which are often shrubs of some size, not only occupy 

 the steep cliffs and rocks in the neighbourhood of the 

 sea, but actually, by their prodigious abundance, con- 

 ceal the old gothic mansions of the interior of the 

 island, overspreading the walls, and in the flowering sea- 

 son making them glow with the most brilliant golden 

 tints; for the Houseleeks of Teneriffo have yellow 

 flowers, while those of Europe have them of a rosy 

 purple colour. 



Such habits are indeed characteristic of all this tribe. 

 In this country, the various races of Sedums, or Stone- 

 crops, are constantly found in such situations ; Sedum 

 acre in particular, spreads its scaly stems and shining 

 yellow starry flowers over the tops of walls in some 

 places near London, and the White Stonecrop is equally 

 abundant in others. An obscure little moss-like an- 

 nual, Tillsea muscosa, overruns bleak, stony, naked 

 commons, here and there ; and on the grey stone walls 

 of the valleys of the Wye and the Dee, and of the 

 west and south-west of England, the graceful Navel- 

 wort (Umbilicus pendulinus) rears its delicate bells 

 of green and gold. 



Besides these plants, Rose-wort (Rhodiola rosea) 

 puts up its purple heads of flow ers in the woods, and by 

 its terrestrial habit establishes the connection between 

 the Houseleek tribe and the commoner forms of vege- 

 tation. 



No tribe of plants can be more easily known than 

 this ; and the White Stonecrop (Sedum album, Plate 



