The rare _P. Bœhmeri_, Schrad. has the glumes merely tapering to a sharp point; and the rare _P. alpinum_, L. has a much shorter spike and glumes ciliate on the keels. The rare _P. asperum_, Jacq. has broad, shortly mucronate glumes and a longer and more slender spike. +(2) Inflorescence a panicle--i.e. tufts or spreading stalked groups of spikelets are arranged on the main axis.+ +A. Inflorescence compact and irregular; a spike of tufts (spike-like panicle). Glumes four, the inner pair awned: paleæ minute. Stamens two only.+ _Anthoxanthum odoratum_, L. The four glumes and two stamens distinguish this grass at once. Other grasses with occasionally tuft-like inflorescences--e.g. species of _Agrostis_, _Gastridium_, _Aira_, _Dactylis_, _Cynosurus_, _Poa_, _Triodia_, _Kœleria_--are distinguished at once by having three stamens (_Bromus_ occasionally has but two), only two glumes, several flowered spikelets, &c. +B. Inflorescence a distinctly branched panicle, more or less loose and spreading.+ (_a_) Tall reed-like perennials, growing in water or in marshes, with plume-like inflorescences, and silky hairs at the base of the paleæ. Glumes with a keel and point, but not awned. (i) Spikelets purplish: outer palea with a slender dorsal awn: basal hairs longer than the paleæ. Leaves narrow. Not common. _Calamagrostis Epigeios_, Roth. (ii) Spikelets greenish. No awns: basal hairs much shorter than the paleæ. Leaves broad. Common. _Digraphis arundinacea_, Trin. A variety of _Digraphis_ with white stripes in the leaves is grown in gardens. Other aquatic reed-like grasses are _Arundo_ and _Glyceria aquatica_: both have several flowers in the spikelet. The rare _Calamagrostis lanceolata_, Roth., _C. stricta_, Nutt. and _C. strigosa_, Hartm. also come here. (_b_) Slender grasses, not reed-like, with delicate loosely spreading panicles of small spikelets. (i) A tall, slender shade-grass, in woods. Paleæ very smooth and glistening. Spikelets few, distant and turgid, awnless. _Milium effusum_, L. _Melica uniflora_, also a wood-grass, has the spikelets two-flowered, though the upper one may be a mere rudiment, and much fewer, on a flexuous nodding axis. The much rarer _M. nutans_ has two perfect flowers in the spikelet (see p. 105). (ii) Grasses of open situations, with numerous small pointed spikelets. Inner palea minute or absent. +Agrostis.+ The genus most likely to give trouble here is _Aira_, which though normally with two flowers in the spikelet, occasionally has but one. As regards the common species of similar habit, &c., _Aira_ has bristle-like leaves and _Agrostis_ flat ones.