STONECROP TRIBE 23 



common in Madeira, the Scinperviviim ghdinosum, is of much service to fisher- 

 men. They rub their nets with the fresh leaves of this plant, and if they are 

 subsequently dipped in any alkaline liquor they are rendered as durable as 

 if they were taimed. Several species cultivated in our gardens and green- 

 houses are very pretty. The Cobweb House-leek has long white hairs at the 

 tips of its leaves, which cross, and present the appearance of a plant over 

 which the spider has trailed its net. 



Our common House-leek has, in July, handsome succulent flowers of a 

 reddish-purple colour. The plant had in earlier times the names of Sengreen, 

 Jupiter's beard, Jupiter's eye, and Bullock's eye. It is called in France, 

 Joubarbe, and in Germany, Hauswurz ; the Italians term it Sempervivo. 



The House-leek must be regarded rather as a naturalized than a native 

 plant. It is rarely, if ever, found in our country even apparently Avild, being 

 usually on walls and house-tops. Schouw, in considering plants in their 

 relation to soils, enumerates some which grow on living or dead animals or 

 plants, and those which grow on artificial substances. These last he divides 

 into wall, ruin, plank, and rubbish plants. Meyen, referring to this, says : 

 " Wall plants are those which appear on the walls of buildings, and certainly 

 are very seldom wanting on them when old ; but as they appear chiefly on 

 very old decayed buildings, ruin plants are not properly distinct from them. 

 As belonging to this class, I may name the lichen called wall lecanora 

 {Lecanora m/uralis), the wall-moss (Dicranum miirale), the fern called wall-rue 

 {Asplcnmm ruta-muraria), the biting stonecrop, the livelong, and many others. 

 But it is right to remark, that all these plants which we have considered as 

 wall and ruin plants can grow quite as well in other situations, on the ground, 

 or on the bark of trees, and on rocks ; and a particular inclination to the 

 artificial situation can only have been ascribed to them because in certain 

 countries they are almost always to be found upon them. This is also the 

 case with roof plants. Thus, the common or roof House-leek, which has a 

 preference for such a habitat, occurs likewise in natural situations ; and the 

 numerous mosses, which in the North grow on roofs of houses, are found on 

 the ground, on rocks, and on the bark of trees." 



This G-erman writer-, following Schouw's division, enumerates as board or 

 plank plants those which grow on wooden palings or similar places. Such 

 are the lichens, the wall parmelia and wall lecanora ; and these grow equally 

 well on wood, or on stone walls, or rocks. On the garden-palings of other 

 countries other plants prevail ; and Meyen says that in East Prussia there is 

 seldom wanting on barn-doors a great quantity of the lichen Ramalina 

 fraxinca, often six inches in length. The rubbish plants are such as grow in 

 the vicinity of dwellings, as the Good King Henry, the borage, and the 

 henbane, which are often found on heaps about houses. 



4. Orpine and Stonecrop (SMum). 



* Leaves flat. 



1. 'Orpine, or Livelong (*S'. teUphium). — Leaves oval, often wedge- 

 shaped at the base, serrated ; flowers in crowded corymbs, interspersed with 

 leaves; stamens 10. Plant perennial. This is the largest of our British 



