108 Transactions. 



Autecology of Moss-forest Plants. 



Metrosideros nervulosa gives out numerous small adventitious rootlets, 

 but I saw none of any size, and only the lower ones reached the ground. 



Aqueous hypoderm is present in Cryplocarya Gregsoni, Negria rhabdo- 

 thamnoides, Olearia Mooneyi, Metrosideros nervulosa, and Coprosma putida. 

 The mesophyll is not differentiated into palisade and spongy tissue in 

 Drimys howeana and Randia stijndosa. In Dracophyllum Fitzgeraldi there 

 is a layer of sclerenchyma beneath the upper epidermis. M 



3. Scrub. 

 Coastal Scrub. 



Along the coast, not far above high-water mark, the forest everywhere 

 passes over, sometimes fairly abruptly, into scrub characterized by its 

 single tier of woody vegetation 1 m. to 3 m. in height, mixed perhaps with 

 a few herbaceous or trailing plants. The scrub at the top of the lower 

 sea-cliffs may be classed in the same formation. 



At Ned's Beach, on the east coast, the scrub is very dense, and can be 

 penetrated only with difficulty. It is composed of prostrate entangled 

 shrubs, whose upper surfaces are shorn down by the wind to a certain general 

 level. The most abundant species here are Celtis amblyphylla. Ochrosia 

 elliptica, Myoporum insulare, Lagunaria Patersoni, and occasionally Hemi- 

 cyclia australasica. In exposed places are Cojwosma prisca and Cassinia 

 tenuifolia, while the trailing plants Spinifex inermis and Caesalpinia 

 Bonducella tend to bind together the already dense thicket. 



There is little variation in this, either in structure or floristic composi- 

 tion, in other parts of the island. Among rocks in the most exposed places, 

 where constant wind carrying salt spray determines the character of the 

 vegetation, Melaleuca ericifolia is sure to be found. At the western base 

 of Mount Grower and at the base of Transit Hill it is this plant, with 

 Corposma prisca, which form the outer edge of the woody vegetation. 

 In West Bay the front facing the sea, but separated from high-water 

 mark by a stretch of sand, is composed of shrubs of low dense growth, with 

 their upper surface presenting an even slope to the wind. The principal 

 species here are Ochrosia elliptica, Myoporum insulare, Rapanea platystigma, 

 and Cryplocarya triplinervis ; also outlying plants of Coprosma prisca. 



On cliffs where small holding-surface and exposure are inimical to the 

 growth of trees detached shrubs constitute the woody vegetation. On 

 the northern sea-cliffs the species are those of coastal scrub — namely, 

 Melaleuca ericifolia, Cassinia tenuifolia, Coprosma prisca, and Myoporum 

 insulare, together with Tecoma austro-caledonica and the tussock sedge 

 Mariscus haematodes. 



On overhanging cliffs at the base of Mount Gower, where the only water 

 available is that which percolates through the rocks, Melaleuca ericifolia 

 was the only shrub noticed ; while on the floor of the cave, where the 

 dripping water fell, there were low straggly shrubs of Cojwosma prisca and 

 Myoporum insulare. 



In a gap between two hills in the north-west of Lord Howe Island, 

 which is swept by westerly winds, an open-scrub association mixes with 

 the herbaceous-plant formations. In the most exposed portions there 

 occur large rounded bushes of Melaleuca ericifolia, 6 m. to 8 m. across and 

 I m. to H m. high, closely fitting the ground all round, and highest in the 

 centre. Other shrubs scattered here and there in the meadow formation 

 are Cassinia tenuifolia, Myoporum insulare, and Coprosma prisca. 



