TOPOGRAPHICAL, ECOLOGICAL, AND TAXONOMIC NOTES. 297 



varnished coat, the latter serving the dual purpose of 

 deflecting the storm-blown sand, and the direct solar rays. 

 This species is recorded in the PI, Austr. i, 354, from 

 Victoria, Tasmania, and South Australia. The omission of 

 New South Wales is obviously a clerical error, as Bentham, 

 loc. cit., refers t. 515, Bot. Reg. to this species. The plate 

 is given as Correa alba, " White Gorrea," or "Botany Bay 

 Tea-tree," and the habitat of the plant depicted as New 

 South Wales. 



The "Pig's-face," Mesembryanthemum cequilaterale 

 Haw., finds in the valley a congenial habitat, where — either 

 individually or collectively — it forms large carpets, the 

 plump succulent leaves, and generally healthy appearance 

 of the plants, demonstrating their appreciation of the shelter 

 afforded. As it approaches the strand, the area of the 

 carpet and bulk of the foliage, diminishes in proportion to 

 its proximity to the region of exposure. Environment has 

 in this case affected the whole plant, leaves, stems, and 

 even the fruits responding to the demand for water con- 

 servation, by becoming succulent, the imprisoned moisture 

 incidentally adding weight to the carpet and strengthening 

 its resistance to displacement by the wind. 



The deep-rooting Pelargonium australe Willd., is occas- 

 ional on the frontal dune slopes, more plentiful on the 

 embankment plateau, but attains its greatest frequency 

 and scope of ramification in the sheltered dune valley. In 

 exposed positions, its rotund leaves spread in a circle, with 

 the lamina turned outwards, and held in a vertical position 

 at a distance from the stem by the elongated petioles, the 

 overlapping whorls forming a close rampart. When the 

 shifting sand bares the rootstock the basal leaves droop, 

 shading and protecting the roots, and encouraging the 

 reaccumulation of the sand by acting as a barrier to its 

 drift. The thickened rootstock is sufficiently firm to support 



