74 Annals of the Carnegie Museum. 



Spikes numerous in oblong panicles; scales not stalked. 



154. Fuirena umbellata. 

 Tribe III. Rynchosporecc. — Spikelets mostly 1-2-flowered; three to many of the 

 lower scales empty; st3'les 2-fid. 

 Spikes in terminal and axillary clusters; bristles commonly present (Ryncho- 

 spora). 

 Style long, the branches much shorter than the undivided part. 



Culms with one head 156. Rynchospora globosa. 



Heads globose, 1-25, laxly paniculate 159. Rynchospora cyperoidea. 



Spikelets 2-6-fascicled, in lax corymbs 161. Rynchospora scutellata. 



Style branches as long or longer than the undivided part. 



Perianth-bristles none 162. Rynchospora pusilla. 



Perianth-bristles present. 



Bristles of the flower plumose 157. Rynchospora plumosa. 



Bristles scabrous in a forward direction. 



Plant robust; achenes not transversely undulate. 



158. Rynchospora cephalotoides. 

 Plant slender; achenes transversely undulate. 



160. Rynchospora rymosa. 



Culm with one globose head; stem leafy 155. Dichromena colorata. 



Tribe IV. SchosnecB. — Spikelets with 3-many lower empty scales; style 3-fid; no 

 tubercle; no bristles 163. Marisciis jamaicensis. 



Flowers never perfect. 



Tribe V. Scleriece. — Flowers monoecious, the staminate and pistillate in the 

 same or diff'erent spikes. 

 Fertile spikelets one-flowered, usually intermixed with clusters of few-flowered 

 staminate spikelets; no bristles (Scleria). 

 Hypogynium present. 



Margin of the hypogynium neither ciliate nor fimbriate. 

 Achene smooth. 



Achene depressed-globose 164. Scleria plerota. 



Achene longer than thick. 



Leaves 2-4 mm wide 165. Scleria Wrightiana. 



Leaves 8-15 mm wide 166. Scleria setidoso-ciliata. 



Achene papillose 167. Scleria ciliata. 



Achene reticulated; hypogynium supporting three deeply 3-lobed 



tubercles 168. Scleria Curiissii. 



Margin of the hypogynium ciliate or ciliolate.. .169. Scleria misrocarpa. 

 Hypogynium none or obsolete. 



Spikelets in a single terminal cluster 174. Scleria gracilis. 



Spikelets in several clusters or spikes. 



Annuals with fibrous roots; inflorescence glomerate-spicate. 



170. Scleria verlicillata. 

 Perennials with rootstocks. 



Inflorescence glomerate-spicate; achene smooth. 



171. Scleria hirteUa. 



