558 GBAMINEiE. (GKASS FAMILY.) 



flowers, 3-nerved on the back, not keeled, scarious-margined. Lower palea ob- 

 long, obtuse, compressed-boat-sbaped, naked, chartaceoas ; the upper very thin 

 and hyaline. Stamens 3. Grain linear-oblong, not grooved. — Perennial, slen- 

 der grasses, with simple and tufted culms, and often sparsely downy sheaths, 

 flat lower leaves, and small greenish (or rarely purplish-tinged) spikelets. 

 (Named for Amos Eaton, author of a popular Manual of the Botany of the 

 United States, which was for a long time the only general work commonly 

 available for students in this country, and of several other popular treatises.) 



1. Ii> obtns^ta. Panicle dense and contracted, somewhat interrupted, the 

 spikelets much crowded on the short erect branches ; upper glume rounded-obovate, 

 truncate-obtuse, rough on the back ; the flowers lance-oblong. (Aira obtusata, 

 Mchx. A. truncata, Muhl. Kceleria trancata, Torr. K. paniculata, Nutt. Ee- 

 boulea gracilis, Kunth, in part. E. obtusata, ed. 1. Eatonia purpurascens, 

 Baf. ?) — Dry soil, N. Penn. to Wisconsin, and southward. June, July. 



2. E. Pennsylvduica* Panicle long and slender, loose, the racemose 

 branches somewhat elongated ; upper glume obtuse or bluntly somewhat pointed ; 

 the 2 (rarely 3) flowers lanceolate. (Kceleria Pennsylvanica, DC. Aira mollis, 

 Muhl. Eeboulea Pennsylvanica, ed. 1.) — Varies, with a fuller panicle, 6'-8' 

 long, with the aspect of Cinna (var. major, Torr.) ; and, rarely, with the lower 

 palea minutely mucronate-pointed ! — Moist woods and meadows ; common. 



30. BIEJLICA, L. Melic-Grass. 



Spikelets 2 - 5-flowered ; the 1 - 3 upper flowers imperfect and dissimilar, con- 

 volute around each other, and enwrapped by the upper fertile flower. Glumes 

 usually large, scarious-margined, convex, obtuse ; the upper 7 - 9-nerved. Palese 

 papery-membranaceous, dry and sometimes indurating with age; the lower 

 rounded or flattish on the back, 7 - many-nerved, scarious at the entire blunt 

 summit. Stamens 3. Stigmas branched-plumose. — Leaves flat and soft. Pani- 

 cle simple or sparingly branched ; the rather large spikelets racemose-one-sided. 

 (An old name, from /leXi., honey.) 



1. M. mfttica, Walt. Panicle simple or branched ; glumes unequal, the 

 larger almost equalling the spikelet ; fertile flowers 2 ; lower palea naked, gla- 

 brous but minutely scabrous on the nerves. 1|. (M. glabra, Michx. M. speciosa, 

 Muhl.) — Var. glXbra (M. glabra, Pursh.) has the panicle often few-flowered 

 and rather simple, the lower palea very blunt. — Var. DiFPtjSA (M. diffusa, 

 Pursh) is taller, 2^° - 4° high, with a more compound and many-flowered pani- 

 cle ; the lower palea commonly more scabrous and its tip narrower. — Eich 

 soil, W. Penn. to Wisconsin, and southward. June. 



31. OLiYCERIA, E. Brown, Trin. Manna-Gkass. 



Spikelets terete or flattish, several - many-flowered ; the flowers mostly early 

 deciduous by the breaking up of the rhachis into joints, leaving the short and 

 unequal 1 - 3-nerved membranaceous glumes behind. Paleae naked, of a rather 

 flrm texture, nearly equal ; the lower rounded on the back, scarious (and some- 

 times obscurely toothed) at the blunt or rarely acute summit, glabrous, 5-7- 



