Oliver. — Vegetation and Flora of Lord Hoin Island. 101 



II. PLANT FORMATIONS OF LORD HOWE ISLAND. 



Synopsis of Formations and Associations. 



Series I. — Woody-plant Formations (Climatic). 



1. Forest. 



Habitat : From sea-level to 600 m. Climatic conditions normal ; well- 

 drained soil. Structure : Trees 8-20 m. tall, palms, pandani, and tree-ferns ; 

 lianes abundant; undergrowth of shrubs, ferns, and herbaceous plants. 

 Associations : Lowland high forest — -Ficus columnaris, Howea Forsteriana ; 

 upland high forest — Acicalyptus Fullagari, Hoivea Belmoreana ; lowland low 

 forest — Hemicyclia australasica, Howea Forsteriana ; mountain low forest— 

 Notelaea quadristaminea, Hedyscepe canterburyana, Pandanus Forsteri. 



2. Moss Forest. 



Habitat : Mountain summits above 600 m. Constant wind, with frequent 

 rain and fog. Structure : Shrubs, palms, and tree-ferns, 3-4 m. tall ; dense 

 undergrowth of shrubs and ferns ; epiphytes abundant, ferns, lichens, and 

 mosses. Association : Dracophyllum Fitzgeraldi, Clinostigma Mooreanum, 

 Cyathea brevipinna. 



3. Scrub. 



Habitat : Edge of forest along sea-coast, and on exposed ridges. Con- 

 stant wind bearing along the coast salt spray. Structure : Shrubs 1-2 m. 

 tall ; few trailing and herbaceous plants. Associations : Coastal scrub — ■ 

 Ochrosia elliptica, Lagunaria Patersoni, Myoporuin insulare, Melileuca 

 ericifolia, Cassinia tenuifolia ; hill scrub — Dodonaea viscosa, Hemicyclia 

 australasica, Rapanea platystigma. 



Series II. — Herbaceous-plant Formations (Edaphic). 

 4. Low Succulent Plants (Halophytes). 



Habitat : Coastal rocks and sand within reach of salt spray. Structure : 

 Herbaceous plants 15-20 cm. tall, with succulent leaves and stems, erect 

 or trailing. Associations: On slopes facing sea — Lobelia anceps, Mesem- 

 bryanthemum aequilaterale ; on rocks near high-water mark — Salicornia 

 australis. 



5. Sand-binders. 



Habitat : Sand-dunes along coast, also sandy exposed headland. 

 Structure : Trailing sand-binding plants, with some herbaceous plants. 

 Association : Spinijex hirsutvs, Ipomaea pes-caprae, Wedelia uniflora. 



6. Rushes. 



Habitat : Exposed (usually sandy) places near coast. Frequent wind 

 bearing salt spray. Structure : Close growth of erect rushes and grasses 

 with trailing-plants. Associations: Sandy flat — Scirpus nodosus, Spinifex 

 hirsutus, Poa caespitosa ; gap in coastal hills — Scirpus nodosus, Poa 

 caespitosa, Phragmites communis, Ipomaea palmata. 



7. Tussock Sedges. 



Habitat : Talus slopes facing sea. Structure : Close growth of large 

 tussocks. Association : Mariscus haematodes. 



