DESCRIPTIONS OF TRIBES AND GENERA. 



83 



74. (22) Phyllorachis Trimen. Each partial spike with 

 one fertile spikelet, and 2-3 



sterile ones reduced to single 

 glumes ; axis prolonged. First 

 empty glume minute, bristle- 

 like, the third glume largest, 

 with a palea in its axil. Be- 

 sides the terminal leaf-like 

 spikes there are solitary, long- 

 pedicelled spikelets in the 

 axils of the leaves. 



Species one (Ph. sagittata 

 Trim.), with sagittate leaves, 

 found at Coanza in Angola. 

 Belationship doubtful. 



75. (23) Thuarea Pers. (Mi- 

 crothuareia Thouars, Orintho- 

 cephcdochloa Kurz). Spikes 

 surrounded by a sheathing 

 leaf ; at maturity the dilated 

 base of the axis envelops the 



1-2 spikelets, and the rest A 



Of the axis, Stripped of its FIG. SS.-Stenotaphrum Americanum 



spikelets, forms a beak which ff a t /L^t *S$uS 

 bores into the ground. A creeping maritime grass. 



Species one (Th. sarmentosa Pers.), from Ceylon to 

 New Caledonia. 



76. (24) Spinifex L. (Fig. 34). The $ spikes with 

 projecting rachis, in dense heads with subtending bracts 

 at the base; spikelets two-flowered; ? spikelets one- 

 flowered, with the pungent-pointed, subtending bracts 

 projecting far beyond them. 



Species four ; three in Australia, the fourth from 

 there to Ceylon and Japan. At maturity the entire ? 

 head falls off and is carried away by the winds or floats 

 on the sea, and finally presses itself into the sand by 

 means of its bristles and falls in pieces. The species are 

 an important agent in binding the drifting sands of the 

 coasts. Leaves usually with hard, rigid points. This 



