1 82 PATAGONIAN EXPEDITIONS I BOTANY. 



N. Patagon. " Very common about Bahia Blanca in the valley of Rio 

 Negro and elsewhere in N. Patagonia." (J. Ball.) 



22. AGROSTIS Linn. Bent-grass. 



Panicles effuse, of very many i -flowered spikelets. Glumes 3, two 

 empty, keeled, acute ; the third or floral glume is shorter, obtuse, often 

 dorsally awned. Palea short or wanting. Grain free, enclosed in the 

 glume. Seed adhering to the pericarp. 



Species 100, cosmopolitan, chiefly in temperate climates. 



KEY TO THE SPECIES. 

 A. Floral glumes awned. 

 b. Leaves glabrous. 

 c. Panicle lax. 



d. Cespitose. Culm 30 cm., naked. Leaves filiform, short. Spikelets minute. Awn 



short, caducous. Palea none (?). kufuitn. 



d2. Panicle nodding or inclined, its rays rough, culm erect, cespitose. Floriglume 



4-toothed. 

 e. Culm 50 cm. Leaves long, linear-lanceolate. Glume 4 mm. long, 3 times as 



long as its flower. magellanica. 



e2. Culm 5-60 cm. Leaves flat. Panicle dense. Floriglume exceeded by its 



awn. antarctica. 



</3. Panicle ovate, its branches forking. Leaves involute. Glumes unequal. Flori- 

 glume broad-ovate. airoides. 

 d^. Panicle green-violet. Empty glumes 3 times as long as the truncate floriglume. 



Awn long, straight. Culms 18 cm., sheathed. rinihuensis. 



c2. Panicle contracted. Culm 27 cm., sheathed. Leaves flat. Glumes violet ; floriglume 



half as long as empty glumes ; awn protruding. vagindta. 



b2. Leaves smooth, but with rough edges. Glumes subequal ; floriglume smaller. 



c. Panicle contracted, rays i-spiculate. Culm 18 cm., sheathed. Palea as long as the 



bifid floriglume. lechleri. 



c2. Panicle lax. Cespitose ; culms 50 cm., nodeless upwards. Palea shorter than the 



obtuse floriglume. paucinodis. 



CT,. Panicle lax, lucidulous. Culms 45 cm., scabrous upwards. exasperata. 



b^. Leaves plane, smooth, but upper surface rather rough. Culms 35 cm., smooth, naked; 

 rootstock creeping. Spikelets minute ; palea none ; floriglume enclosing grain, often 

 awnless. pyrogea. 



b^. Leaves pubescent or scabrous. 

 c. Culms smooth. 

 d. Panicle lax. 



e. Panicle straw-purple, oblong. Culms 35 cm., with leafy offsets. Leaves 



setaceous, pungent. A floral rudiment. nardiflora. 



2. Panicle dense, cernuous, many-rayed. Culm 75 cm., leaf-sheaths glabrous. 

 Awn terminal, short. patagonica. 



