494 GRAMINE^. [PoA. 



Spikelets T V in. broad, green and purplish-brown ; empty glumes ovate, acute, 

 keel scabrid ; fl. glumes also broad, acute. DISTRIB. Europe, N. Africa, 

 Siberia. Very near P. alpi'na, but differing in locality, habit, and the close 

 ovate panicle. 



39. GLYCE'RIA, Br. MANNA GRASS. 



Perennial tall grasses ; leaf sheaths entire. Spikelets linear, snbterete, in 

 effuse or contracted panicles, many-fld., branches in |- whorls ; rachilla 

 jointed between the fl. glumes. Empty glumes 2, shorter than the lowest 

 flowering, 1-5-nerved, unequal, membranous, convex, awnless ; upper 

 larger. Fl. glumes caducous, cartilaginous, convex, not keeled, tip obtuse 

 usually scarious ; nerves 3-9 evanescent upwards. Palea 2- fid, nerves 

 ciliate. Scales fleshy, truncate. Stamens 3. Ovary glabrous ; styles 

 terminal, short or 0, stigmas feathery. Fruit oblong, enveloped and 

 sometimes adnate to the fl. glume, channelled. DISTRIB. Temp, and 

 cold climates ; species 30. ETYM. y\vKep6s, in allusion to the sweet 

 grain. 



SECTION 1. Hydrochloa. Scales fleshy truncate or 0. Fruit thick 

 obtuse, hardly compressed, furrow very narrow or 0. 



1. G. aquat'ica, Sm. ; panicle much branched, spikelets oblong, fl. 

 glumes 5-9 entire. G. spectab'ilis, Koch. 



Watery places, from Elgin and Mall southd. ; Ireland; Channel Islands; fl. 

 July-Aug. Rootstock stout, extensively creeping. Stems 2-6 ft., stout, 

 smooth, striate. Leaves 1-2 ft., J- in. broad, flat, suberect, acute ; sheaths 

 smooth ; ligule short. Panicle 6-12 in. Spikelets ^ in., yellow-green and 

 purple; glumes scabrid; empty short, shining; flowering rigid, obtuse; 

 nerves strong. DISTRIB. Europe, Siberia, Himalaya, N. America. 



2. G. fiu'itans, Br. ; panicle subsimple, spikelets linear, fl. glumes 

 7-20. 



Watery places, N. to Shetland; ascends to 1,600 ft. in Yorkshire; Ireland; 

 Channel Islands ; fl. July-Aug. Rootstock stout, widely creeping. Stem 1-3 

 ft., stout,branched, terete, floating or creeping, smooth. Leaves 3 | in. broad, 

 flat, acute, short, or the upper long and floating ; sheaths Jong, compressed ; 

 ligule broad, acute. Panicle 1-2 ft., simple or branched ; rachis 3-gonous ; 

 branches remote, smooth. Spikelets j-2 in., erect, green or tips purplish; 

 empty glumes unequal, tips torn ; fl. glumes scabrid, tips often ragged. 

 DISTRIB. Europe, N. Africa, W. Siberia, Himalaya, N. America. A very 

 variable plant. 



VAR. G. plica'ta, Fr., has divaricate fruiting spikelets, and fl. glumes twice as 

 long as broad. VAR. G. pedicella'ta, Towns., has broader blunter leaves, 

 with rough furrowed sheaths, 3-toothed fl. glumes, not exceeding the palea 

 (it never fruits). VAR. G. declina'ta, Brebiss, is a dwarf form with smooth 

 sheaths, few-fld. spikelets, and the palea longer than the 3-toothed fl. glume. 

 Hampshire and Scilly Islands. 



SECTION 2. A'tropis, Rupr. (gen.). Scales slender, distinct. Fruit 

 thick, dorsally compressed, ventrally hollow or broadly furrowed. 



