MACLOSKIE: GRAMINE^E. 165 



when mature, bristles pointing upward. Floral glume oval, coarsely 

 rugose across. 



(Eur. & N. Amer.) ; N. Patagon. 







2. S. SETOSA Beauv. (S. caudata Roem. & Sch.) 



60-90 cm. high. Culm slender, erect, flattened, branching below, nodes 

 glabrous. Leaves scabrous, twisted, flat, blades to 20 cm. long, 4 mm. 

 broad, apex long, slender. Panicle interrupted cylindrical, 18 cm. by 7 

 mm., its axis pilose; bristles 1-3 to each spikelet, 3-10 mm. long, point- 

 ing upwards. Spikelets 3 mm. long ; first glume broad, 3-nerved ; second 

 and third glumes equal, a neutral flower in the third ; which is y-nerved. 

 Palea small. Floral glume wrinkled across. 



(Tropical regions, New Mex. and south.) Common in North Patagonia. 



8. CENCHRUS Linn. Bur-grass. 



Leaves flat. Inflorescence spicate, the spikelets subtended by a spiny 

 involucre which at length falls off with the seed as a spiny bur. Glumes 

 4, the third often enclosing a staminate, and the fourth being the flower- 

 ing glume of the perfect flower. 



Species 12, in warm countries. 



C. TRIBULOIDES LlNN. 



Root annual. Involucres crowded on the scabrous rachis, 2-flowered, 

 globose. Spines of burs stout. (N. Amer., Br. & Br. i, 127.) 

 N. Patagon. 



9. LUZIOLA Juss. 



Creeping water and marsh monoecious grasses with narrow leaves, and 

 male and female i -flowered spikelets in separate panicles, rarely in the 

 same and then the male spikelets terminal. Rays of panicle filiform. 

 Stamens exceeding 6 (to 18). Female flowers small. Styles 2, distinct. 

 Grain elliptical, free from the pericarp. 



Species 6, Brazil to Alabama ; i in Patagonia. 



L. SPRUCEANA Benth. 



Culm glabrous, rooting at the nodes ; the upper leaf-sheaths ventricose, 

 striate; ligule long-acuminate; lamina linear, narrowly acuminate, ner- 



