4*6 ECOLOGICAL .STUDY OF SALTMARSH VEGETATION. 



ing an almost pure sward of Seablite which conveys the impres- 

 sion of a strip of lawn enclosed by hedges. 



On the drier parts of the plain the Seablite gradually loses its 

 decumbent habit and discards its lateral surface roots. A simi- 

 lar alteration in the habit of the northern iSuaeda fruticosa grow- 

 ing on a shingle beach is noted by Oliver and Salisbury (31, 

 p. 260) . The Seablite was not observed by the writer on the 

 ocean shore-Line, but Benthain* notes it as abundant on shingle 

 beaches close to high water mark in Tasmania. 



The formation of salt crystals in the stems and their extrusion 

 from the epidermis as in Salicomia, was also noted in dried 

 specimens of the Seablite. 



In typical local estuarine bays the tide-flooded area on the 

 littoral boundary extends to the marsh banks, a series of irregular 

 formations, chiefly low, carpet-forming succulents, occupying the 

 space between the Salicornia and the reeds. In this station the 

 former is intruded by occasional patches of Wilsonia Backhousii 

 Hook, f., a creeping, stoloniferous perennial with a flat carpet. 

 There are three species of Wilsonia, none of which is admitted 

 by Bentham into the flora' of New South Wales, f but they are 

 all recorded in local publications, and there are specimens in 

 the National Herbarium of W. rotundifolia Hook, from Lake 

 Cudgellico and Lake Bathurst, and of W. Backhousii from the 

 local marshes. The genus is endemic in the Commonwealth, 

 New South Wales and Tasmania representing respectively its 

 northern and southern limits. 



Where the tidal detritus has extended the base of the bank 

 into a terrace, the Wilsonia creeps over it, consolidating the drift, 

 its compact formation of crass fleshy leaves, closely appressed 

 to the soil, narrowing with the deposit into a band, or, where 

 the bank rises abruptly from the marsh, into a mere fringe. At 

 Homebush Bay, a Wilsonia formation an acre or more in extent 

 was noted on a comparatively dry peaty stretch of the salt-plain, 

 where, under the drier conditions and loose soil, it is unable to 

 maintain a continuous carpet, breaking up into small mats or 

 stools. The Wilsonia is essentially halophytic and does not 

 extend to the fluvial zone. The genus is a degenerate offshoot 

 of the Convolvulaceae, a family largely constituted of climbers 



* Flora Austr., v., p. 206. 

 t Flora Austr., i\\, 439. 



