_Poa_, 2, 15, 20, 21, 23, 25, 26, 47, 54, 61, 74, 83, 84, 88, 89, 90, 91, 92, 103, 104, 109, 110, +113+, 114, 115, 116, 118, 127, 131, 140, 141, 144, 146, 151, 162; _P. alpina_, 8, 11, 13, 14, 16, 17, 31, +44+, 54, 63, 114, 134, +146+; _P. annua_, 8, 10, 14, 16, 30, 34, 42, +53+, 54, _63_, 68, 74, 75, +114+, _127_, 141, +146+; _P. aquatica_--_Glyceria aquatica_; _P. bulbosa_, 8, 11, 14, 29, +54+, 69, 111, 114, 146; _P. compressa_, 8, 11, 14, 15, 16, 30, 32, 42, +53+, 54, 63, 69, 74, 111, +114+, 139, +140+; _P. distans_, 29, 30, 114, 146; _P. fertilis_--_P. serotina_, 45; _P. fluitans_--_Glyceria fluitans_; _P. laxa_, 31, 134; _P. loliacea_, 31, 108, 114, 146; _P. maritima_, 8, 11, 14, 16, 20, 22, 26, 29, +47+, 54, +111+, 114, 146; _P. nemoralis_, 7, 11, 14, 15, 28, 34, 45, +54+, 63, 74, 75, 113, +114+, 139, _140_, +141+, 161; _P. pratensis_, 7, 11, 13, 14, 16, 17, 27, 32, 33, 41, 42, +44+, 45, 54, 55, 67, 75, 113, +114+, 139, +140+, 141; _P. procumbens_, 31, 111, 114; _P. rigida_, 10, 14, 30, +111+, 114, 146; _P. stricta_--var.of _P. alpina_, 134; _P. trivialis_, 7, 11, 13, 14, 16, 17, _18_, 27, 32, +42+, 44, 45, 54, +74+, 90, 112, +113+, 139, _140_, +141+, 146, 148 Pollen, _93_, 94, 119 Pollen-grain, _120_, +121+ Pollen-tube, _120_, +121+ Pollination, _93_, 119, +120+, +121+ _Polygonum_, 3 _Polypogon_--Beard-grass, 69, 90, 91, 92, 100, 101, 109; _P. littoralis_, 31; _P. monspeliensis_, 31 Ponds, grasses of, 28, 29 Popular names, 6 Potassium salts, 32 Prairies, 1, 36, 38 Prickle-hairs, 66 Primary root, 123, 131 Procumbent Meadow-grass--_Poa procumbens_ Protandrous--when the pollen is mature and shed before the stigma of the same flower is ready for pollination, 119 Proterogynous--when the stigma is receptive before the pollen of the same flower is mature, 119 _Psamma_, 4, 11, 13, 14, 21, 25, 36, 48, 79, 81, 89, 90, 92, 95, 138; _P. arenaria_, 7, 29, 33, 35, 36, +48+, 70, +79+, +102+, 138, +139+ Pubescence--hairiness, 26 Pungent--spine-like, 22 Purple-flowered Small-reed--_Calamagrostis lanceolata_ Purple-stalked Cat’s-tail--_Phleum Bœhmeri_ Purple-veined sheaths, 18 Quadrangular shoot-section, 16, 40 Quake-grass--_Briza_ Quaking-grass--_Briza media_ Racemous--like a raceme, 105 Rachilla, 85, _123_, _124_, _128_, _129_, 131, _137_, 138, 142, _143_, 144, _149_, _150_, _164_, _167_, _169_, _170_, _172_ Rachis, _9_, 85, 88, 106, 107 Radicle, _121_, 123 Rare grasses, 6, +30+, +31+, 89, 90, 91, 92 Rat’s-tail Fescue--_Festuca Myurus_ Red-sheathed grasses, 18, 49, 59 Reed, 2 Reed Canary grass--_Digraphis arundinacea_ Reed Fescue--_Festuca sylvatica_ Reed-grass, 1, 6 Reed Meadow-grass--_Glyceria aquatica_ Reed Sweet-grass--_Glyceria aquatica_ Reflexed leaves, _16_