TOPOGRAPHICAL, ECOLOGICAL, AND TAXONOMIC NOTES 321 



Several prostrate divaricately-branched examples of a 

 small undershrub Micrantheum ericoicles Desf., are scat- 

 tered on the headland. In its customary habitat on the 

 peaty margin of a swamp it is upright, and there is no 

 ramification of the branches. This species extends from 

 National Park to Queensland, and creeping round on the 

 coastal sandstone has reached and ascended the Blue 

 Mountains to a height of 2,000 feet at Hazelbrook. Phe- 

 balium squamulosum Vent, is dwarfed when subjected to 

 exposure on the headland, though in sheltered positions it 

 may reach its normal height, 3-4 feet. The plants in this 

 station have much broader leaves than those of a form 

 growing in a well favoured position among the alluvial 

 detritus on the banks of the Nepean River at Douglas Park. 



The " Native Rose," Boronia serr ulata Sm., is suspected 

 of parentage in the production of a natural hybrid, B. 

 serrulaba x B. floribunda Sieb., 1 both of which are found 

 on the headland. The former has a limited range on the 

 coastal sandstone from Gosford to Port Hacking. Acacia 

 suaveolens Willd., one of the earliest flowering Wattles, 

 has shorter leaves when growing on the headland than its 

 confreres on the landward sandhills. An orbicular, fleshy 

 leaved form of Trachymene Billardieri F.v.M. var. crassi- 

 folia Benth., occupies a frontal position on the ledges above 

 the escarpment. Of this variety Bentham, (Fl. Austr., iii, 

 357) says, "...and at first sight it appears to be a well marked 

 species but the differences may possibly be due to a sea- 

 coast station." 



A glumaceous association of tufted plants, which intermix 

 freely, is established on the shallow sand patches and soil 

 pockets on the rock benches. Of these, Lepidosperma 

 viscidumTl. Br., has adopted the xerophytic device denoted 

 by its specific name. On a warm day, when the viscid 



1 Proc. Linn. Soc. N.S. Wales, Vol. xl, p. 419. 

 U— October 3, 1917. 



