Mr. Woods on the Genera of European Grasses. 13 



some species of Andropogon itself,) wiiere in some g^enera the sessile spiculse 

 are perfect, and the stalked ones barren. Pairs or groups of spiculse occur 

 also in Dlgitaria, but on a one-sided rachis, and in Elymus and Hordeum, 

 where they are on a rachis with opposite channels. 



3. Spiculse solitary, in a panicle, with a rudiment or imperfect floret within 

 the outer glume of the calyx, or even with a rudiment or imperfect floret on 

 each side, but below the perfect floret. This description applies to all the 

 Phalaride^ except Lygeum and Zea, which have only a doubtful claim to a 

 place in that tribe, and to Arrhenatherum. Among the Oryze^ also several 

 of the foreign genera are described as having indications, more or less com- 

 plete, of an imperfect inferior floret, though the two European genera exhibit 

 nothing of the sort. Ctenium among the ChloridevE, and some of the Rott- 

 BOELLiACE^, are said to have external imperfect florets or rudiments, which, 

 however, occur in no European genus of these tribes. Panicum also would be 

 included under this head. 



4. Spiculse in two rows on one side of a flattened rachis. This is the in- 

 florescence of the remaining European PANicEiE and of the Chlorides. It 

 occurs, as already stated, in most species of Andropogon, in Nardus, and in Cy- 

 nosurus cristatus. In Knappia the rachis is not flattened or triangular. Triticum, 

 Nardus, and T. unilaterale belong to this division, and perhaps Oreochloa. 



6. Spiculse with more than one perfect floret disposed in a panicle equal all 

 round. This contains the remaining Arundinace-«;, the Avenace^, except 

 Arrhenatherum ; and among the Festucaceje, Poa, Glyceria aquatica, Catu- 

 brosa, Melica, Molinia, Koeleria, Schismus, and Bromu^. 



6. Spiculse in a one-sided panicle. In other respects like the last. This 

 contains the remainder of the Festucacece, except Sesleria, which belongs to 

 the following. 



7. Spiculse in a spike or head, tiled all round. Here we place Echinaria and 

 Sesleria. 



8. Spiculse in opposite rows, on an alternately channeled rachis. This divi- 

 sion includes the Hordeaceoe and Rottboelliacece, with some exceptions, which 

 have been already noticed. The description would also apply to Festuca mari- 

 tima {Triticum maritimum, Auct.), and F. divaricatu, and to Gaudinia {Avena) 



fragilis. 



