Mr. Woods on the Genera of European Grasses. 39 



The spiculse of Avena are said to be 3 or more flowered, but we cannot 

 depend on this character, since A. satlva and A. orientalis have only 2 ; 

 and this is sometimes the case with A.fatua, A. hirtula, A. amethystina, 

 A. brevis, and A. alba, among the Grasses of Europe : we must, therefore, 

 chiefly I'ely upon the furrowed and crested seed to distinguish it from Aira as 

 well as from Trlsetum. The awn is said to be from the base of the palea in 

 Aira, and from the back in Avena, and the former has a shining panicle, but 

 there are exceptions both ways to each of these circumstances. 



Gaudinia is readily distinguished by its spiked florets and unequal glumes, 

 and I think there is no danger of its being referred to any other tribe. The 

 geniculate dorsal awn is not to be found among the Hordeacece or Rottboelli- 

 acece. 



Arrhenatherum and Holcus are suflBciently marked by the characters 



above given. The habit of the plant obliges me to place here the first of these 



genera in spite of the outer imperfect floret. It cannot be confounded with 



any of the Panicece or Phalaridece. The membranous and strongly-ribbed 



palese and geniculate dorsal awn keep it quite distinct from these families. 



Danthonia decumbens has been considered as a Poa and as a Festuca, and it 



might seem, therefore, probably to belong to the Festucacece, but I think 



Kunth has done well in placing it here. I am in this principally guided by 



the large membranous glumes, and by its close affinity to D. provincialis, 



from which it differs almost in nothing but in the want of the twisted upper 



part of the awn. Without pretending to decide whether Triodia, of which I 



know nothing, be really a distinct genus, I cannot agree with those who would 



separate these two species. 



Festucace^. 



. This is on the whole a very distinct tribe, although closely allied by some 

 of its genera to the Avenacece on the one hand, and to the Hordeacece on the 

 other. The spiculse are scattered, many-flowered. The glumes are unequal, 

 shorter than the spicula, generally thinner than the outer palea, never of a 

 thicker or firmer substance. The outer palea is usually more or less distinctly 

 nerved or ribbed, herbaceous or membranous, not coriaceous while the plant 

 is in flower, but in some species hardening on the seed ; while in others the 

 inner becomes attached to the seed without alteration. They generally have 



