1890.] |J q/ South African Plants to the Climate. 37 



or salt. All succulents are protected in this way, gum occurring 

 in the Acacias, salt in Augea capensis and Zygophyllum Marlothii 

 and slime in a great many others. The amount of salt is often so 

 large, that during the drying of the plant it crystallises and forms a 

 thick crust on it. 



7. The plants possess special organs for the absorp- 

 tion Of dew. Such organs are specially adapted hairs, glands or 

 sheaths, and they will be particularly useful to plants occurring in 

 localities, which are dry but often visited by fog or clouds. The hairs 

 on the leaves of Salsola Zeyheri enable it to exist in the coast districts 

 of the Kalahari region, where rain is a rare occurrence. I found the 

 little shrubs on the rocks near Angra Pequena, and later on in numerous 

 specimens in the Namib, the desert eastward of Walfish Bay. In the 

 same way the Naras plant most likely derives some benefit from the 

 water deposited on its branches by the thick fog which so often occurs 

 along the Western coast. 



The depressed glands at the base of the acacia leaves seem to serve 

 the same purpose, for drops of dew running down along the rachis 

 must moisten them. The handsome Rochea coccinea, which adorns 

 the rocks of Table Mountain with its dark crimson flowers, has fleshy 

 leaves like its allies, but the leaves are fringed with little teeth. Each 

 tooth, however, is an inflated cell which absorbs the moisture deposited 

 on it by the South-East cloud. 



Another plant found on the South-Western mountains, namely 

 Watsonia Meriana, utilises the water deposited on it in a different 

 way. It grows at an altitude of 2,000 feet and more, is four to six feet 

 high and flowers in December and January, the middle of our dry 

 season, when rain is a very rare occurrence. The stem usually consists 

 of five or six internodes, each surrounded at its base by a large inflated 

 sheath, which is almost closed at the top. These sheaths always 

 contain water, even many weeks after rain has fallen, and I have often 

 been glad to meet the plant with its hidden treasure on my rambles 

 over dry parts of the mountain, for there is sometimes an ounce of 

 water in a single sheath. 



It is derived from the clouds that cover the mountain during the 

 South-East wind* As two other species of Watsonia, of similar size 

 ( W. rosea and marginata), which flower earlier in the season and 

 occur mostly at a lower level where the mist rarely reaches them, do 

 not possess such pitchers, the natural conclusion seems to be that the 

 plant draws on this resource for the development of its flowers and 

 seeds. This is, however, not the case* Anatomical examination and 

 a series of experiments have shown me, that the stem cannot absorb 

 this water, but that it is there . only for the use of the sheaths* As 

 the sheaths, however, protect the more delicate regions of the stem 



