The Book of Grasses 



KEY TO THE GENERA 



I . — Flowers in each spikelet all, or at least one of them, perfect. 

 II. — Stamens and Pistils in separate flowers. 



I. — Flowers in each spikelet all, or at least one of them, perfect. 



Spikelets 2-many-flowered, flat or nearly so, usually clustered in 

 terminal umbels; scales 2-ranked; bristles none; stems leafy near 

 base. Cyperus 260 



Spikelets 6-io-flowered, flat, slender, on axillary peduncles; bristles 



present; stems leafy. Pond Sedge .... 270 



Spikelets solitary, several-many-flowered, terminating the stems; 

 bristles usually present; leaves reduced to basal sheaths. 



Spike-rushes .... 272 



Spikelets roundish, several-many-flowered, in terminal umbels; 

 bristles none; stems leafy near base. 



Leaves thread-like. Sand-mat 272 



Leaves narrow, flat. Fimbristylis .... 272 



Spikelets solitary or many, roundish, several-many-flowered; 

 terminal or in terminal umbels or clusters; bristles usually pres- 

 ent; stems leafy or the leaves reduced to basal sheaths. 



Club-rushes, or Bulrushes 280 



Spikelets solitary or several, several-many-flowered, terminal or in 

 terminal umbels or clusters; bristles usually many, long and silky, 

 at maturity much exceeding the scales in length; stems more or 

 less leafy. Cotton-grasses . . . 300 



Spikelets few-flowered, in terminal and axillary clusters; lower scales 

 empty; bristles usually present; stems leafy. 



Beaked-rushes . . . 300 



II. — Stamens and Pistils in separate flowers. 



Staminate and pistillate spikelets in the same or in different clusters; 



staminate spikelets many-flowered, pistillate spikelets i-flowered; 



bristles none; seed not enclosed in a sac; stems leafy. 



Nut-rushes .... 303 

 Staminate and pistillate flowers in the same or in different spikes; 



seed enclosed in a sac; stems leafy. Sedges 304 



CYPERUS. (Cyperus) 



The sedges of this genus have been known under different 

 names, and as "Galingale," "Earth-nuts," and "Bulrushes," 

 many species have served the world since the days of remote 

 antiquity. The far-famed Papyrus of the Nile is a Cyperus whose 

 many uses it is unnecessary to recount, and in Isaiah we note the 



260 



