The next point to notice is that not every grass has so many as two fertile flowers and one barren one in its spikelet, as the Oat has. A spikelet may have one (_Phleum_), two (_Aira_) or three (_Avena_) or more (_Poa_) fertile flowers, and no barren ones or several, the number of flowers being counted by the number of pairs of pales found inside the pair of glumes. Moreover every flower is not necessarily fertile (e.g. _Arrhenatherum_, _Holcus_) and several grasses have one or more flowers in each spikelet containing _stamens_ only--male flowers--while others may have _ovaries_ only--female flowers. In some exotics the male and female flowers are on different parts of the same plant (Maize) or even on different plants (_Gynerium_), an arrangement not met with in our grasses. Accordingly, it is of importance in determining a grass to discover how many flowers the spikelet contains, and whether any are male only, or barren, &c., as well as to make out the character of its inflorescence. In the following lists I have brought together some of the chief points with illustrative examples. SPIKELETS with only one perfect flower (without rudimentary ones). _Psamma._ _Milium._ _Nardus._ _Alopecurus._ _Phleum._ _Hordeum._ _Agrostis._ And species of the rare grasses _Calamagrostis_, _Mibora_, _Lepturus_, _Spartina_, _Cynodon_, _Gastridium_, _Lagurus_, _Polypogon_, _Leersia_. SPIKELETS with one perfect flower and one or more male or rudimentary ones. _Digraphis._ _Anthoxanthum._ _Holcus._ _Arrhenatherum._ And the rare genera _Hierochloe_ and _Panicum_. SPIKELETS with at least two perfect flowers. _Molinia._ _Arundo._ _Avena._ _Aira_ (some species). _Bromus._ _Cynosurus._ _Dactylis._ _Triodia._ _Sesleria._ _Kœleria._ _Melica_ (one species). _Briza._ _Poa trivialis._ _Catabrosa._ SPIKELETS with at least three perfect flowers and usually more. _Elymus._ _Agropyrum._ _Brachypodium._ _Lolium._ _Festuca._ _Poa._ _Glyceria._ INFLORESCENCE, a spike of single spikelets. _Agropyrum._ _Brachypodium._ _Lolium._ _Nardus._ And varieties of _Festuca Myurus_ and _F. loliacea_, &c. INFLORESCENCE, a spike of pairs or tufts of three or more spikelets. _Elymus_ (pairs). _Hordeum_ (threes). _Cynosurus_ (clusters). INFLORESCENCE, a cylindrical closely tufted spike-like panicle. _Phleum._ _Alopecurus._ _Psamma._ _Anthoxanthum._ INFLORESCENCE, a compact more or less tufted panicle. _Molinia._ _Kœleria._ _Triodia._ _Dactylis._ _Aira præcox._ _A. canescens._ _Sesleria._ And rare grasses like _Polypogon_, _Gastridium_, &c. INFLORESCENCE, a loose plume-like or branched panicle. _Avena._ _Bromus._ _Arrhenatherum._ _Catabrosa._ _Aira_ (except _A. præcox_ and _A. canescens_). _Arundo._ _Digraphis._ _Milium._ _Agrostis._ _Melica._ _Holcus._ _Poa_ (most of the species). _Glyceria._ _Briza._ _Festuca_ (except _F. Myurus_).