6 Salter, Flora of Teneriffe. 



thick-leaved Helianthemum canariense. From above Guimar the 

 two recent lava-flows of 1705-1706 are seen meandering through 

 this desert country to the sea, supporting after two centuries scarcely 

 any vegetation but a tufted lichen (Stereocaulon) . Where a little 

 water is available, parts of this coast desert are terraced for vines or 

 tomatoes, but between Guimar and Santa Cruz there is scarcely an 

 orange-tree, while so hopeless is the country in the other direction 

 that, on approaching Arona, one even welcomes the reappearance of 

 Opuntia. Fig-trees, however, are more general and in the dry season 

 remain the embodiment of greenness and shade. Old individuals 

 cover a large area, the main branches bending downwards to take 

 root and send up secondary stems from the points at which they 

 touch the ground. 



The native vegetation of the coast-belt, including the arid, rocky 

 ravines which furrow it, illustrates every possible adaptation to semi- 

 desert conditions. With the exception of the fresh green of Plocama, 

 its general aspect is grey, many plants being either glaucous or 

 covered with a silky, mealy or hoary pubescence. The leaves of others 

 contain aromatic or acrid principles, while another group (Sonchus 

 spinosus, Lycium afrum) depend for protection upon their tough, 

 wiry nature and armament of spines. Reduction of leaf-surface is 

 seen in Reseda scoparia, Convolvulus scoparius and in the numerous 

 " switch plants," such as Retdma Spachii, Plocama pendula, Sonchus 

 leptocephahts, Linaria spartea and scoparia, Campylanthus salso- 

 loides and Asparagus scoparius. The plants of the sun-scorched 

 barrancos are extremely deep-rooted and many (as the larger species 

 of Sempervivum) only flower at the expense of nutriment accumu- 

 lated in the course of several or of many years. 



These characters are nowhere better seen than in the vegetation 

 of the old lava-flow which has issued from the Montaneta de Guimar. 

 The latter is still a perfect cone, with the sides of its crater overgrown 

 with vegetation. Here are vast thickets of the cactus-like Euphorbia 

 canariensis , each stiff quadrangular column beset with four rows of 

 spines. It is often overgrown by the climbing Asclepiad Periploca 

 IcBvigata, known as " comical," from its horn-like fruits. Intermixed 

 with the thickets of Euphorbia, and profiting by the protection which 

 they afford — no small matter when all-devouring goats everywhere 

 range at large— are other desert shrubs such as Sonchus leptocephalus, 

 the white-powdered, yellow-flowered Cneorum pulverulentum, Messer- 

 schmidia fruticosa (Boraginaceae) and Asparagus arboreus. 1 



The curious Asclepiad Ceropegia dichotoma appears as a cluster 

 of fleshy, upright, jointed meal-covered stems, having thus much the 

 appearance of a bunch of wax candles. The few grasses, as Aristida 

 ccerulescens and Tricholcena Teneriffce, are of characteristically desert 

 type. Near at hand upon the loose black sand Plocama pendula 



1 The following were also noticed here or elsewhere finding safety in a close 

 association with Euphorbia canariensis : — Rhamnus crenulata, Argyranthemum 

 fceniculaceum, Kleinia nereifolia, Convolvulus floridus and Canarirta campanula, 

 while Statice imbricata was seen growing under the protection of Euphorbia 

 regis-JubcB. 



