The leading Physiognomic Plants, — Dune Plants. 49 
The roots are very long, but little branched and descend deeply. 
Juvenile plants growing in hollows show little trace of the subsequent 
rhizome development, which depends upon a constant sand-burial. > 
S. frondosus belongs to an endemic sub-genus (Desmoschoenus) thus affor- 
ding an excellent example ofa very special adaptation developed in an isolated 
region. occurs throughout both the main Islands, Stewart Island and u 
Chatham 
b. Spinifex hirsutus Labill. (Gramin.). (Plate V, Fig. 6). 
5. hursutus is a powerful sand-binding grass. The creeping stem is ex- 
tremely long, much-branching, smooth, hard, flexible and woody. At first it 
creeps on the surface of the sand, rooting at the nodes, the internodes about 
ı2 cm long. It is soon covered by the advancing sand, though the apex 
may again emerge to the light, but usually it is only che branches or leafy 
shoots which do so, these latter frequently ascending through the sand from 
a stem 5o cm below. The leaf consists of blade and sheath. A normal blade 
is 47 cm long by 1o mm broad and tapers to a fine, but usually dead, point. 
The texture is thick and coriaceous, but flexible; both surfaces are thickly 
covered with adpressed silky hair. The sheath is about 11.5 cm long, pale, 
thick and fleshy. Near the apex of.a surface-creeping rhizome the leaves re _ 
smaller with shorter blades and broader sheaths. The roots are numerous, 
slender, wiry and often more than ı m long. The flowers are dioecious. 
The male spikes are numerous, about 8 cm long and form a terminal umbel 
with sometimes 2—3 spikes making a cluster below. The female inflores- 
cence is a large globose head, sometimes 30 cm in diam., composed of ı—2- 
flowered spikelets each at the base of a long, sharp-pointed, radially spreading 
spine some’ 12.5 cm long. EOUREBOR occurs from the ae of November. 
to the middle of Dece BE 
'S. hirsutus is ART to the Norte: Central Er N. of the South 
botanical: provinces, its southern limit being about. age ai it also ir 
BEBSHR N in Australia and New Caledonia. ee 
e. Carez puma Thunb, öremen. | 
