TOPOGRAPHICAL, ECOLOGICAL, AND TAXONOMIC NOTES. 319 



isolation. At the southern end of the beach the dune is 

 merged into the headland, a belt of dwarfed plants of 

 Banksia serrata L., 3-5 feet high, lining its base a few 

 yards above the flood waters of the lagoon. The headland, 

 as it extends seawards, develops the usual escarpment 

 which continues along the ocean front to Freshwater Beach. 

 On its frontal ledges Selliera radicans, a species whose 

 proclivities are estuarine rather than littoral, creeps along 

 the surface of the shallow mud in erratic lines, which, in 

 favoured positions, become united into small carpets. The 

 broad succulent leaves which are closely appressed to the 

 ground, act in conjunction with its underground stem and 

 root system, as a protective agency against the displace- 

 ment of the soft earth by the rock seepage. This species 

 has a climatic range from a few miles north of Port Jack- 

 son, south to New Zealand, and is also found in extra- 

 tropical South America. 



In a shallow water channel on the hillside, a series of 

 plants, ligneous and herbaceous, find a congenial habitat. 

 Of the shrubs, Callistemon linearis DO., has rigid linear 

 leaves, the oldest of which, those at the base of the branches, 

 it discards in response to a diminished water supply. Its 

 frequent associate Hakea pngioniformis Oav., does not 

 under similar conditions shed its leaves, but shortens them 

 and arrests the internodal elongation, which results in leaf 

 aggregation and consequent reduction of the isolated 

 surface. Representative herbaceous plants in the water- 

 channel are Goodenia bellidifolia 8m.,Velleia lyrata R.Br., 

 and Stypandra umbellcita R.Br., all of which have rosulate 

 leaves, flattened on the ground when the surface is flooded 

 and the foothold insecure, relaxed and uplifted as the sur- 

 face dries and a measure of stability is restored. The first 

 named has a considerable coastal range, and ascends the 

 eastern slopes of the dividing range to the tableland in 



