104 Festuceae Poa 



6. Glyceria septentrionalis Hitchc. {Panicularia septentrioyudis 

 (Hitchc.) Bickn. and Glyceria plicata of Deam, Grasses of Ind.) Eastern 

 Mannagrass. Map 144. Infrequent to somewhat frequent in the lake area 

 and local in the southern part of the state. It has the habitat of the 

 preceding species, growing only in very wet places or in shallow water. 



Que. to Minn., southw. to S. C. and e. Tex. 



7. Glyceria acutifldra Torr. (Panicularia acutiflora (Torr.) Kuntze.) 

 Map 145. In 1919 I found this grass in an artificial pond in Harrison 

 County. The pond was revisited in 1935 and this species was still a common 

 plant in it. R. M. Kriebel found it in 1934 in a sinkhole on the farm of 

 Julius Blackwell, about two and a half miles northeast of Springville, 

 Lawrence County. On July 29, 1935, he found about a half acre in a but- 

 tonbush swamp of about three acres on the Cobb farm about two miles 

 northeast of Avoca, Lawrence County. Here it was associated with 

 Cephahinthiis occiolentalis, Populus heterophylla , Rosa palustris, Glyceria 

 septentrionalis, and Ranunculus flabellaris. 



N. H. to Mich., southw. to Del. and Tenn. 



10-378. POA L. Bluegrass 



Annual, usually less than 40 cm high. 



Lemmas not cottony at the base, plainly 5-nerved; mature anthers 0.7-1 mm long. 



1. P. annua. 



Lemmas cottony at the base, 3-nerved or with two additional obscure ones; mature 



anthers about 0.2 mm long 2. P. Chapmaniana. 



Perennial, usually more than 40 cm high. 



Lemmas not cottony at the base 3. P. autumnalis. 



Lemmas cottony at the base. 



Plants bluish green; culms from creeping rootstocks, not tufted, distinctly 

 flattened; panicles contracted after anthesis and usually less than 1 cm wide 

 (shade forms sometimes slender and spreading and as wide as 2 cm), 



branches of panicle erect; first glume 3-nerved 4. P. compressa. 



Plants green (not bluish) ; culms terete or only slightly compressed; panicles 

 more or less expanded after anthesis, at least 2 cm wide, branches ascending 

 or spreading; first glume 1-nerved except in P. Wolfii. 



Lemmas glabrous 5. P. langitida. 



Lemmas pubescent or scabrous, at least on the keel. 

 Marginal nerves of lemmas glabrous. 



Sheaths smooth; intermediate nerves of the flowering glume obscure; 

 spikelets 4-6 mm long; anthers 0.4-0.7 mm long, pink; ligule 1 mm 

 long or less; inflorescence silvery green, without spikelets close to the 



rachis 6. P. ahode>:. 



Sheaths scabrous; intermediate nerves prominent; spikelets 3.2-3.0 mm 

 long; anthers 1.6 mm long, pale; ligule 5-6 mm long; inflorescence 

 yellowish green or purplish, with normal rays and, in addition, many 



spikelets on short branches closer to the rachis 7. P. trivially. 



Marginal nerves of lemmas pubescent. 

 Intermediate nerves of lemmas obscure. 



Plants slender, lax; ligules less than 2 mm long; anthers often purple, 

 0.5-0.8 (1) mm long; branches of panicles in 2's (rarely in 3's). 

 8. P. paludigena. 



Plants robust; ligules more than 2 mm long; anthers 0.8-1.4 mm long; 

 branches of panicles in .'!'s or more 9. P. palustris. 



