548 CVII. GRAMINE^E. \_P6d. 
* Spikelets linear or subcylindrical {rarely ovate, with the glumes 1 -nerved). 
Florets convex on the back at the base. 
f Outer glumella with 7 prominent ribs and a scarious margin, neither 
hairy on the ribs, nor webbed at the base, subcylindrical, obtuse. 
Glumes 1 -nerved, conspicuously unequal. Glyceria Br. 
1. P. aqudtica L. (Reed M.) ; panicle erect large and much 
branched spreading, branches scabrous, spikelets linear oblong 
of about 5 — 10 florets, outer glumella with 7 ribs, sheaths of 
leaves cylindrical. E. B. 1. 1315 : Parn. Gr. t. 44. Glyceria Sm. 
Sides of rivers, ponds, and ditches. Tf.. 7, 8. — Rhizome creeping. 
Culms 4 — 6 feet high, erect. Leaves erect, linear-lanceolate, rough on 
the edges. Ligule short, obtuse. Glumes small, ovate, obtuse. Outer 
glumella twice as large as the glumes ; inner narrower and bifid at the 
point. 
2. P .fluitans Scop. ( floating M., or true Manna croup-grass ); 
panicle unilateral or nearly erect, spikelets linear of 7 — 20 
florets, outer glumelias obtuse or slightly acute with 7 ribs and 
short intermediate ones at the base, sheaths of leaves compressed. 
Festuca L. Glyceria R. Br. — a. sheaths of leaves even or striate, 
panicle spreading in flower but erect in fruit, rachis smooth, 
outer glumella nearly thrice as long as broad, anther 4£ — 5 
times longer than broad. Parn. Gr. t. 95. — f3. sheaths of leaves 
sulcate, panicle always spreading, outer glumella scarcely twice 
as long as broad, anther about three times longer than broad. 
E B. 1. 1520: Parn. Gr. t. 45. Glyceria plicata Fries. G. pe- 
dieellata Towns, in Ann. Nat. Hist. 2nd ser. v. p. 105. 
Ditches and stagnant waters, abundant. If. 7, 8. — A variable 
species, sometimes confounded with Festuca pratensis 13., but distin- 
guished by the 1 -nerved glumes and 7-ribbed glumelias. Culms 
creeping, or floating and rooting near the base; flowering ones 1 — 3 
ft. high, thick and succulent. Leaves linear-lanceolate, keeled, more 
or less folded at the keel %vhen young ; lower ones floating. Sheaths 
of a. sometimes so striate as almost to appear sulcate. Ligule oblong, 
pointed. Panicle with the branches more or less spreading in flower, 
adpressed (in a. ) or divaricate (in (8.) when in fruit, nearly simple 
(forming a raceme or loose spike) or with simple or compound 
branches. Glumes unequal, small, ovate, obtuse. Glumelias ovate- 
oblong, sometimes thrice as long as the glumes, but variable in that 
respect ; outer ones scabrous, sometimes toothed. Hypogynous scales 
thick, fleshy, usually united into one piece. There are two forms of 
B.; one (G. plicata Fr.) with the branches of the panicle simple or 
compound, and small sessile or shortly stalked spikelets ; the other 
(G. pedicellata Towns., and perhaps P. fluitans Parn. Gr. t. 45) with 
the panicle unilateral and the branches always simple, and spikelets 
nearly as large as in a. on smooth and usually slender stalks. All 
these and other forms, although distinguished from each other with 
