32 Mr. Woops on the Genera of European Grasses. 
PiPrATHERUM is a genus of 4 or perhaps 5 species, all European, which were 
separated by Palisot de Beauvois from Agrostis and Milium. Kunth says of the 
spiculæ of PreraruEnUM, “basi haud articulate.” Iam ignorant of the precise 
import of this phrase. None of the Séipaceæ are described as having the spi- 
culæ articulate at the base. Such a character might well be given to a plant, 
for instance, like Imperata cylindrica, where the whole spicula, glumes in- 
cluded, readily separates from the callus which supports it. In Melica alsó 
the calyx appears to fall off; but in most Grasses the separation of the floret 
takes place within the glumes, and this seems to be the case with all the 
Stipacee. In S. aristella the floret is sessile, and the awn neither geniculate 
nor twisted ; perhaps it ought to form a distinct genus, or be united to Pipta- 
therum. Inthe Mantissa it is called an Agrostis. In all the other species the 
awn is geniculate and generally with two knees, which, howev 
er, are not very 
acutely bent. 
The part between the knees is less closely twisted than the 
lower part of the awn, but in the same direction. Two broad ribs run down 
the awn, and each side of each rib is furnished with a row of hairs, which in 
some species are short and bristle-like, in others soft and long, or bristly in 
the twisted part, and longer and finer in that which is not twisted. Duby in 
the Bot. Gall. describes S. capillata “ aristis basi rectis apice tortilibus;" but 
iem » wem erroneous. I have preferred the name of ACHNATHERUM given 
y Palisot de Beauvois to the inadmissi j ] 
from Link by Kunth. It is true that sae ede 5 0 iam 
uded by the first- 
mentioned writer, which succeeding botanists do not acknowledge; but as 
these are sunk in other genera, they form Sere : 
19 objection to the a iati 
the name to this. In habit the Europea rend 
approach to Arundo. x = probably the Siberian species 
ÁRUNDINACE X, 
This tribe, like the following, contains some 
lants of whi ; 
one-flowered, and others in which they ure m Plants of which the spiculæ are 
any-flowered, but with so much 
> 
I follow other botanists in finding 
hairs which envelope the florets, but I confess it t 
stinguish the tribe on this ground. Some a 
already observed, are not entirely destitute 
