50S ECOLOGICAL STUDY OF SALTMARSH VEGETATION. 



a narrow conical growth but in this moist sheltered station they 

 develop an umbrageous habit. At Hen and Chickens Bay a 

 group of Turpentine trees, Syncarpia laurifolia Ten. — sympto- 

 matic of the shale— was noted on the hillside at no great distance 

 from the marsh. The River Mangrove, Aegiceras majus Gaertn., 

 is indifferently represented in the local marshes, the largest for- 

 mation observed occurring in a marsh on the southern bank of 

 Port Hacking River, near the entrance. This species is mor3 

 frequent locally on the banks of tidal rivers than in the marsh 

 proper, several clumps occurring on the banks of Cook's River, 

 and on the banks of George's River at Como, always ranging 

 behind the Grey Mangrove. In the latter locality several trees 

 of the Grey Gum, Eucalyptus punctata DC, were noted in a 

 formation of J uncus maritimus on the muddy river bank. The 

 halophytic tendency of the Grey Gum is shown in a record of 

 its habitat by J. H. Maiden,* " Kuring-gai Chase, at edge of 

 salt-water, near house-boat. W. F. Blakely." A bush of 

 Viminaria denudata Sm. had also penetrated the ranks of the 

 J uncus formation a considerable distance into the tideway. 



In the vicinity Poly gala my rti folia L., an aggressive, soft- 

 wooded shrub introduced from South Africa as an ornamental 

 garden plant, has escaped from cultivation and spread round 

 the sides of an amphitheatre-shaped gap in the river bank which 

 had been cleared and grassed. The original indigenous vegeta- 

 tion is already reasserting itself, the Native Grapes, Vitis 

 Baudiniana F. v. M., and V. hypoglauca F. v. M., climbing over 

 the Poly gala bushes and enveloping them. 



On the rock benches overhanging the river a series of succu- 

 lent epiphytes form small clustered colonies. Of these, the 

 somewhat rare Calandrinia Pickeringi A. Gray, and Peperomia 

 leptostachya Hk. et Am., are occasional, their associate Plec- 

 tranthus parviflorus Henck., occurring more frequently and 

 forming larger colonies. Though these herbs are usually found 

 in shady situations, they can nourish under strong illumination, 

 occasionally growing on rock ledges exposed to direct sunlight 

 for the greater part of the day. The two former species rarely 

 depart from the epiphytal habit of growth but the Plectranthus 

 is more adaptable and on occasion becomes a troublesome weed 

 in cultivated land. 



* Critical Revision of the Genus Eucalyptus, iii., p. 197. 



