482 
PACIFIC SCIENCE, Vol. XX, October 1966 
Fig. 4. Root system of Eucalyptus papuana in black clay soil of transect 2. (The camera looks obliquely 
down into the pit.) Under the basal whorl of main horizontal roots a small taproot can be seen, which divides 
into upward-bending roots. 
where the shoots originate. These vertical roots 
taper rapidly and the deepest penetrations ob- 
served were about 0.9 rn. From them branch 
off horizontal and downward rootlets of diam- 
eters varying between 1 and 2.5 mm. 
Cycas media has its main distribution on the 
slopes; some specimens, however, were found 
near gullies and the gallery forest margin. It 
was completely absent on the intermediate, 
flatter parts of the transects. Usually Cycas 
remains low, 0.5 or 1 m high, but occasionally 
it reaches heights of 4 m. 
For the sake of completeness the occurrence 
is mentioned of a few specimens of Pandanus 
sp., Antidesma ghaesembilla, Timonius timon, 
and Desmodium umbellatum, growing on black 
clay soil along the gullies and creeks. 
The Ground Layer 
GENERAL composition: The ground layer 
is composed mainly of grasses, of which 
Theme da australis, Heteropogon contortus, and 
Sehima nervosum are the commonest; Capil- 
lipedium spicigemm and Sorghum nitidum are 
subordinate; and Cymbopogon procerus, Dichan- 
thium superciliatum, Themeda novoguineen- 
sis, and Panicum sp. are occasionally found. The 
season was not very favourable for the study of 
other herbs. Some dried sedges were found, of 
which only Eleocharis monostachyos on black 
clay soils was recognizable. Among the forbs the 
Papilionaceae were best represented: Lourea 
obcordata , Crotalaria linifolia, Alysicarpus 
vaginalis, Uraria lagopodioides, Pycnospora 
lutescens, Tephrosia Pmaculata, and four species 
not yet identified, of which two were twiners. 
Among the others were: Passi flora foetida 
(Passifloraceae), Evolvulus alsinoides (Con- 
volvulaceae) , Melothria maderaspatana (Cu- 
curbitaceae), Tridax procumbens (Composi- 
tae) PBorreria sp. (Rubiaceae), and several 
Labiatae. Because of the general poor condition 
