332 



A. A. HAMILTON. 



sometimes bears flowers at the top of the horns of the 

 fruits. " An example of this unusual form of heterotaxy in 

 the New Zealand Spinach, was exhibited before the Linnean 

 Society by the writer. 1 



Apium prostratum has in this region remodelled its leaf 

 dissection, varying it from t-he linear segmentation of the 

 lobes of the inland form, to a broad obtuse lobing, an alter- 

 ation of form noted by Bentham, PI. Austr. iii, 372, in a 

 reference to the maintenance of two distinct species of 

 this herb, a proposition with which he was not in agree- 

 ment. The breadth of the lobes is still further accentuated 

 when the plants are growing in the strand sand. Its fre- 

 quent associates on the escarpment, Samolus repe-ns, and 

 Lobelia aneeps, rarely descend to the beach, and are unable 

 to establish their colonies on the open strand. The latter 

 prefers to creep among the rushes and sedges in a swamp, 

 and in such a situation narrows and elongates both stems 

 and leaves. Samolus repens also frequents the swamp but 

 reaches its maximum growth in the estuary, where it 

 frequently lines the low muddy banks with a broad marginal 

 band, occasionally many hundred yards in length, or invades 

 the precincts of a Mangrove forest. The creeping stolons, 

 netted below, and the decumbent stems, matted above, 

 bind the community together, enabling it to ride secure 

 from tidal invasion on the unstable mud. 



On the escarpment the Buffalo Grass exhibits a greater 

 exposure resistant capacity than the Common Couch, 

 (Cynodon) carpeting the rock ledges for some distance down 

 the face of the cliff, the Couch rarely venturing from its 

 haven on the parapet above. Zoysia pungens has again 

 demonstrated its superiority over both its congeners, by 

 descending to the spray-drenched soil pockets at the base 

 ■of the escarpment. 



1 Pro:. Linn. Soc. N. S. Wales, Vol. xxxix, p. 513. 



