MR. d. BENTHAM ON GRAMINEM. 95 
flowers, and the glume usually unawned ; but 4. pulchella, Willk., 
with the glume awned, cannot be otherwise distinguished from 
it. Periballia, Trin., is the A. involucrata, Cav., in which the 
two flowers are as in A. agrostidea rather distant from each other, 
the lowest flowering glume unawned, the upper one awned, but 
both flowers hermaphrodite, as in the rest of the genus. The 
inflorescence of this species is rather peculiar ; the lowest whorl of 
branches of the panicle are usually without any or with only very 
few spikelets, and were regarded by Cavanilles as an involucre : 
but that is not always the case; I have seen some specimens 
with spikelets on all the branches. A. sabulonum, Labill., from 
New Caledonia, is a very doubtful plant. Labillardidre's figure 
isa good representation of the Australiasan form of Sporobolus 
virginicus, except that the spikelets are drawn as two-flowered. 
The specimens sent for Labillardiğre's plant by Pancher and by 
Vieillard have only one flower in the spikelet. 
2. CORYNEPHORUS, Beauv. ( Weingartneria, Bernh.), comprises 
two European grasses, extending into North Africa and more 
sparingly to the Levant, with the continuation of the rhachilla 
of Deschampsia, but readily distinguished by the peculiar articu- 
late club-shaped awn of the flowering glumes. 
3. DESCHAMPSIA (Campelia, Link) is a genus of about twenty 
species, from the temperate or colder regions of both the New 
and the Old World, sparingly represented in mountain regions 
within the tropics. It bears the same relation to Aira that 
Deyeuxia does to Agrostis; the plants are usually perennial and 
stouter than in Aira, the spikelets larger, and the rhachilla is 
produced beyond the upper flower into a bristle often bearing a 
tuft of hairs, and sometimes an empty glume on even a male 
flower; the flowering glumes are also frequently more or less 
dentieulate. No less than six of the species have been proposed 
as distinct genera :-—Vahlodea, Fries, is D. atropurpurea (Aira. 
atropurpurea, Wahlenb.), a northern species, with the flowering 
glume not at all or only very minutely denticulate, otherwise 
quite a Deschampsia. Avenella, Parlat. (Zerchenfeldia, Schur), 
is the common D. flexuosa (Aira flexuosa, Linn.), with the flower- 
ing glume surrounded by hairs. The grain is said by Parlatore 
to adhere to the palea, which may be sometimes, but is certainly 
not always, the case. Monandraira, Em. Desv., includes two 
Chilian species, Zpisetum Berteroanum and T. aireforme of Steudel, 
separated from Deschampsia as having but one stamen to the 
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