<J Mr. Woods on the Genera of European Grasses. 



which I adopt. He does not seem to have found it necessary to assign a 

 name for the two together. I shall with Linnaeus term it a corolla, but 

 composed of two palece instead of petals. This nomenclature seeuis more 

 unobjectionable than that of calyx to the outer covering; and if Mr. Brown 

 has not absolutely proved, he has at least shown it to be highly probable that 

 these parts are analogous to the outer series of a hexapetalous corolla. 

 ' Awn. Attached to the outer palea we frequently find an awn, whose presence 

 nature and position are often very iiseful in determining species, and sometimes 

 in characterizing genera. Palisot de Beauvois maintains that two organs es- 

 sentially distinct have been confounded under this name. To one of them he 

 applies the name of seta, and describes it as the prolongation of a nerve, 

 whose base forms part of the substance of the palese. It is not necessary that 

 it should accompany the palese for the whole length of the latter, but may 

 divide from it in any part. The awn originates suddenly from the substance 

 of the palea, and if there should be a nerve below, it is much smaller than the 

 awn, and is considered to be prolonged into a seta embraced by the awn 

 and adhering closely to it. When bi'oken off, the awn leaves behind no trace 

 of its existence. Neither Duby nor Kunth seems to acknowledge this distinc- 

 tion. Gaudin adopts it with some modifications. P. de Beauvois has added 

 to the above characters that the awn is stronger than the seta, and of a firmer 

 texture. Gaudin, on the contrary, shows that the awn is frequently as fine, 

 tender and delicate as any seta, as in j4ira and Agrostis, which are acknow- 

 ledged to be awned by P. de Beauvois himself; and, on the other hand, in 

 Triticum, whei'e both authors are agreed that the terminating point is a seta, 

 it is firm and thick, so that few awns can exceed it. He takes, therefore, 

 principally for his guide its fragility at the point of insertion. P. de Beauvois 

 assigns a seta to Festuca and Brachypodium, and an awn to Bromus. Gaudin 

 considers all these genera as setigerous. The nature of the arm may doubt- 

 less afford sometimes a very useful distinction, but I am afraid it will be 

 impossible to regard it as including two things which can always be clearly 

 distinguished. The seta is a mere continuation of the midrib. The aivn is 

 something different or something more ; the peculiarity pointed out by Gau- 

 din will usually explain its nature. 



Scales ; Squamul^. Within the outer palese, but without the stamens, are 



