September, 1939 
The Queensland Naturalist 
61 
is Sporobolus diander. This species forms dense narrow- 
leaved tufts of considerable size with culms up to 3-4 feet 
in height. Moisture appears to be the more important 
factor in its distribution. 
Where the Fringing Forest has been removed, and on 
the occasional mudbanks? Echinochloa crusgalli , E. colona 
and E. Walteri? occur. The two first-mentioned are com- 
paratively small plants, E. crus-galli attaining 2 feet, while 
E. colona is usually less than 1 foot. They have rather 
succulent stems and broad leaves with awnless, pale-col- 
oured spike! et-s. E. Walteri? on the other hand is a much 
larger plant. It is much more erect, more densely tufted, 
with a large dense panicle rendered conspicuous by the 
numerous long purple awns. All these species are readily 
eaten by stock. E. colona occasionally appears as a weed 
of cultivation. The grasses on the bank in the more open 
parts are chiefly water couch ( Paspalum distidhum) and 
Indian couch (Cynodon dactylon) with Blue Couch ( Digi - 
taria didactyla ) just behind. On the gravel pits the first 
grasses to appear are Cynodon , and the annuals 
Echinochloa colona , Set aria glauca and the closely allied 
S. pallidifusca. As soil is deposited there is a tendency 
for the Cynodon to be driven out by Digitaria didactyla. 
Two very interesting grasses along the North Pine 
River are Vetiveria filipes and Setaria genicndata. The 
former is a densely tufted grass with a leafy base and 
flowering culms up to 3 feet high bearing a somewhat con- 
tracted purple panicle. It frequently occurs among rocks, 
and is never found far from the water’s edge. The Setaria 
also has a tufted leafy base, but it has a distinct horizontal 
rhizome, and a green spike-like bristly inflorescence. This 
grass has been found a short distance from the river. 
RAILWAY ENCLOSURES. 
In railway enclosures a characteristic but very varied 
grass vegetation occurs. The commonest species are 
Rhynchelytrum repens (red Natal grass), Themeda 
australis (kangaroo grass), Alloteropsis semialata (cocka- 
too grass), Aristida gueenslandica and A. vagans (spear 
grasses), Imperata cylindrica var. Koenigii (blady grass), 
and Capillipedium parviflorum (scented golden beard). 
In general it may be said that the less the soil has been 
disturbed by banking or excavation, the greater the ten- 
dency for Themeda to dominate the vegetation, and the 
greater the amount of disturbance, the commoner Capilli- 
pedium becomes. Sorghum verticUliflorum, which is very 
common nearer Brisbane, is only known in one small patch, 
