112 A FLORA OF MANILA 



slender. Spikelets red or reddish-brown, spreading, slender, rather laxly 

 disposed, 1 to a cm long, 10- to 25-flowered, the glumes obtuse, oblong- 

 elliptic, remote, 2 mm long. Nut oblong, 1.3 to 1.5 mm long» 



In open grass lands, San Juan del Monte and other places, fl. all the 

 year; throughout the Philippines. Tropics generally. 



10. C. rotundus L. Muth^ (Tag.). 



A slender, erect, glabrous perennial 10 to 40 cm high, the. rhizomes 

 wiry, bearing black, hard, ovoid tubers about 1 cm in diameter. Stems 

 usually solitary, 3-angled above. Leaves 5 to 15 cm long, or sometimes 

 as long as the stems, 3 mm wide or less. Umbel simple or compound, 

 2 to 6 cm long, the rays long or short, the spikes dense or rather lax, of 

 from 3 to 8 spikelets. Spikelets brown, slender, 10 to 25 mm long, 10- 

 to 25-flowered, the glumes 2.5 to 3 mta long. 



In gardens, lawns, waste places, etc., very common, fl. all the year.; 

 throughout the Philippines. In all warm countries. 



11. C. zollingeri Steud. 



A slender glabrous perennial 10 to 50 cm high, the stems mostly soli- 

 tary. Leaves 5 to 20 cm long, 2 mm vnde or less. Umbels simple or 

 compound, rather lax, of few long and short rays, sometimes reduced to 

 one, the spikes rather lax, of from 2 to 6 spikelets. Spikelets brown, 

 slender, 1 to 2.5 cm long, 10- to 15-flowered, the glumes about 3 mm 

 long, rather distant. Nut 3-angled, 2 mm long. 



In open, dry grass lands, Masambong, fl. July-Sept.; not common in the_ 

 Philippines. Tropical Asia and Africa, through Malaya to Australia. 



12. C. radiatus Vahl. 



A coarse, erect, tufted perennial 0.2 to 1 m high. Leaves one-half to 

 two-thirds as long as the stems, 7 mm wide or less, the bracts subtending 

 the inflorescence leaf-like. Inflorescence compound, umbellate, brown, the 

 rays long or short. Spikes 3 to 6 at the end of each branch, sessile, 

 dense, cylindric, 1.5 to 4 cm long, 6 to 8 mm thick, Spikelets 4 to 5 mm 

 long, T.2- to 18-flowered, the glumes about 1.2 mm long. Nut ovoid, about 

 0.9 mm long. 



In open wet lands and swampy places, common, fl. all the year; through- 

 out the Philippines. Widely distributed in the tropics. 



5. MARISCUS Gaerther 



Coarse or slender tufted plants, usually perennials, rarely annuals. 

 Leaves mostly basal, sometimes cauline, the bracts leaf-like. Inflores- 

 cence of umbelled heads or spikes. Spikelets more or less compressed; 

 glumes distichous, the rachilla of the spikelet disarticulating above the 

 2 lowest glumes. Nut trigonous; style 3-fid. 



Species about 160 in all warm regions, about 8 in the Philippines. A 

 genus very closely allied to Oyperus, differing chiefly in the articulated 

 rachillas. 



1. Umbels simple. 



2. Spikes cylindric, dense, about 2 cm long; spikelets usually 2-flowered. 



1. M. cyperinus 

 2. Spikes linear, lax 2. M. fldbelliformia 



