60 
The Queensland Naturalist 
September, 1939 
OPEN SWAMPS. 
Open swampy tracts are rare, but a few small ones 
do occur. The characteristic species is water couch, 
Paspalum distichum. This is a bright green, extensively 
creeping grass rarely more than 2-3 inches high. Quite 
frequently it grows floating on water. Panicum Buncei 
and Pseudoraphis squarrosa are very similar in appear- 
ance and habit. They only appear when free water is 
present, Leersia hexandra , a rather tall though diffuse 
grass up to 6 feet long, sometimes occurs. Where free 
water is not present, Sacciolepis indica , Paspalum orbi- 
cular e, Ischaemum australe , Paspalum dilatatum and 
occasionally Cynodon dactylon occur. The Sacciolepis is 
a scarcely tufted slender grass of from 2-20 inches high 
with a narrow leaden grey spike-like inflorescence. These 
areas are bordered by a Paspalum dilatatum,- Digit aria 
didactyla associes which then passes into the ordinary 
Digit aria, etc., community. 
STREAM BANKS. 
Along the banks of the larger water-courses (North 
Pine River, Sidling Creek and One Mile Creek), a char- 
acteristic suite of grasses occurs. The two factors con- 
trolling the presence of these species are moisture and 
shade. Where both these factors are at a maximum, 
Ottochloa gracillima occurs. This is a creeping grass 
with narrow lanceolate shining green leaves, ascending 
flowering culms and a small panicle. It does not leave 
the stream banks. With it occurs Oplismenus aemulus, 
a plant of similar habit with rather broader, usually dis- 
tinctly hairy, dull green leaves and a slightly different 
inflorescence. This species is by no means confined to 
stream banks, but is common everywhere where suitable 
conditions prevail. Beneath a lantana bush is a favourite 
station. Entolasia marginata resembles the Ottochloa 
more than the Oplismenus. Tt enters the open forest but 
is rare. 
In less densely shaded places Microlaena stipoides and 
Eriochloa procera are fairly common. They also extend 
into the open forest. The Eriochloa has pale green 
leaves, tufted at the base with erect or diffuse culms. 
Echinopogon nutans and E . ovatus are grasses of similar 
habitat but are rarer. E. ovatus causes staggers in 
horses. 
A characteristic grass behind the Fringing Forest, and 
a species met with in most damp more or less shady places 
