POA.] GRAMINEJE. 493 



in., slender, nodding. Spikelets small, i- in., yellow-green and purplish ; 

 empty glumes often equalling the flowering, acuminate; fl. glumes 2-5, 

 scarely hyaline at the tip or margins. DISTRIB. Europe, N. Asia, Hima- 

 laya, N. America. Yery variable. I am quite unable to define the forms 

 into which it has been divided, and about which no two authors are agreed. 

 I recognise the following British varieties, but I cannot correlate them with 

 exotic ones satisfactorily. The characters taken from the length of the 

 upper leaf and its sheath and the position of the upper node are valueless. 

 YAR. P. Parnell'ii, Bab. ; smaller, more slender, with smaller spikelets. 

 YAR. P. Balfour'ii, Parn. (P. monta'na, Parn. ; ? P. cce'sia and ylau'ca, Sm.) ; 

 stouter, panicle more erect, spikelets larger. Alpine cliffs ; ascends to 

 3,000 ft. 



6. P. lax'a, Hcenke ; steins slightly compressed, leaves short, ligules 

 long torn acute, branches of narrow lax subsecund panicle solitary or 2-nate 

 smooth, fl. glumes 2-4, keel and margins villous, nerves 3-5 obscure. 

 Rocks, on the alps of Aberdeen and Inverness ; alt. 2,000 to 3,600 ft. ; fl. July- 



Aug. Flaccid, smooth, pale glaucous green. Steins 4-10 in., compressed and 

 prostrate below. Leaves linear, obliquely mucronate, upper longer than its 

 sheath; sheaths compressed. Panicle 1-3 in., drooping, lax or open, 

 branches rarely scaberulous. Spikelets T ^- in., often viviparous, green and 

 purplish ; empty glumes acuminate, tips hyaline. DISTRIB. N., Alpine, and 

 Arctic Europe, Siberia, N. America. Often with difficulty distinguished 

 from P. alpi'na. 



P. LAXA proper ; leaves channelled tip concave, panicle open in flower closed 

 in fruit. P.flexuo'sa, Sm.; P. mi' nor, Gaud. 



Sub-sp. P. STRICTA, Lindb. ; leaves flat to the tip, panicle open in flower 

 spreading in fruit. 



7. P. alpi'na, L. ; stems glabrous terete, leaves broad firm tip rounded, 

 upper ligules long acute, branches of erect spreading panicle 2-nate, fl. 

 glumes 3-9, keel and margins pubescent, nerves 3-5 obscure. 



Eocks, &c., on lofty mts., N. Wales, York to Sutherland ; alt. 3-4,000 ft. ; W. 

 Ireland, very rare ; fl. June-Aug. Smooth. Rootstock stout, creeping. 

 Stems 10-18 in., stout. Leaves rather short, strict, rigid, keeled, mucronate, 

 edges thickened scabrid, upper shorter than its sheath; lower sheaths 

 broad, white, membranous, persistent, leafless, upper compressed smooth. 

 Panicle oblong or pyramidal, 1-3 in. broad. Spikelets ^ in., green and 

 purplish, often viviparous ; empty glumes unequal, ovate, acute ; fl. glumes 

 with hyaline tips, webbed, also broad. DISTRIB. N., Alpine, and Arctic 

 Europe, N. and W. Asia, Himalaya, N. America. 



8. P. bulbo'sa, L. ; lower nodes tuberous, stem and terete sheaths 

 smooth, leaves narrow, ligules all long acute, branches of panicle 2-nate 

 scabrid, fl. glumes 3-6, margins and acute keel pubescent, nerves 

 obsolete. 



Sandy seashores, Norfolk to Kent and Devon; fl. April-May. Glabrous, 

 rather rigid. Stems 6-10 in. ; tubers ovoid, |~J in., covered with lax sheaths. 

 Leaves 1-1^ in., very narrow, keeled, curved, upper very short; lower 

 sheaths short, upper long compressed. Panicle 1-1 in., ovate, compressed. 



