88 
The Queensland Naturalist October, 19 30 
edges of the Malayan forest. Pure grassland of this type 
is to be seen on some of the smaller islands adjacent to 
Great Palm. The species forming it are heliophilous and 
re-colonization of the area by forest is preceded by a 
smothering of the grasses. Particularly important in this 
regard is Passiflora foetida, a passion vine whose glan- 
dular hairs produce a sticky foetid secretion Ipomoea 
quinata, a small convolvulaceous vine found amongst these 
grasses is too small to have any smothering effect. Macar- 
anga tanarius is a pioneer tree in the invasion of the 
grassland and the grasses are gradually eliminated be- 
neath its canopy, and seedlings of forest trees make their 
appearance. Homalanthus populifolius, another pioneer, 
is not nearly so important as a suppressing agent. 
Swamps. 
Two types of swamp formation are met with on Palm 
Island — the freshwater swamps of the low-lying plain on 
the western side of the island, and the somewhat brackish 
swamps found on lower flats to which the sea has a very 
limited access. 
(a) Freshwater Swamps. 
The plain enclosed by the horse-shoe range on the 
western side is drained imperfectly by a mangrove-lined 
creek and its tributaries which, in the wet season, are 
fed by the mountain streams sweeping down rocky gorges. 
The low-lying country is very swampy, and water lies 
about for the greater part of the year. Part, of it has been 
drained and cleared, and the reclaimed area planted with 
coconuts, bananas, papaws, melons, and minor crops. 
Constant firing of the dried reeds and ringbarknig of the 
trees has altered the original vegetation to a great extent, 
and open forest species and weeds have invaded the orig- 
inal swamp areas. Chief amongst these are Urena lobata, 
Hibiscus radiatus, II. tiliaceus, ITeteropogon contortus, 
and Passiflora foetida. The latter tends to smother the 
Heteropogon, which is one of the first immigrants. 
In the few untouched swamps the characteristic vege- 
tation is an association of Melaleuca leucadendron with 
Phragmites communis. The paper-marked Melaleucas are 
stout trees of thirty to forty feet with their bases in a 
few feet of water. Phragmites,. the red, grows thickly 
between. Towards the edges of the swamp is found 
Polygonum barbatum, and a Seirpus, not flowering at the 
time, grows in occasional clumps. On the higher land the 
Melaleuca still occurs, but the reeds and rushes are re- 
placed by Anthistiria imberbis, with an occasional ITetero- 
pogon contortus. Where fires bad swept this higher land 
the Anthistira was destroyed and its place taken by Het- 
cropogon (To ]y e continued.) 
