96 MR. G. BENTHAM ON GRAMINEX. 
flower; but iu D. Berteroanum I have sometimes found two 
stamens, and in the evidently nearly allied D. antarctica, Hook. f., 
the stamens, though usually three, are sometimes two only. 
Airidium, Steud., is a species from the Straits of Magellan which 
I am unable to distinguish from the D. antarctica. Rytidosper- 
mum, Steud., is founded on specimens of a Deschampsia closely 
allied to, if not identical with, the common D. cespitosa, in which 
a grub has taken possession of every spikelet remaining in the 
panicle, and has been mistaken by Steudel for the caryopsis, and 
actually described as such. Peyritschia, Fourn., is D. helerioides 
(Aira kalerioides, Peyr.), which I have not seen, but which, from 
Peyritsch's elaborate description, must be very near to D. ant- 
arctica, Hook. f., D. nitida, Presl, and D. holeiformis, Presl. 
4. ACHNERIA, Munro, contains eight South-African species, 
with one from south-eastern tropical Africa, referred by Nees to 
Eriachne, and by Kunth to Airopsis, but evidently more nearly 
related to Deschampsia. 
5. MoNAcHynos, Parlat., is a single species from the Cape- 
Verd Islands, which we have not at Kew, and of which I have 
therefore been unable to verify the character given by Parlatore. 
The specimen he described most probably remained in Webb’s 
herbarium, now deposited at Florence. 
6. Horcus, Linn., formerly included two very different groups 
of grasses ; and Brown specially retained Linnæus’s name for that 
one which now forms the genus Sorghum in Andropogones, 
whilst all modern botanists restrict the genus Holcus to the other 
group, consisting of about eight European or African species, 
chiefly western, of whieh one or two are common weeds in various 
parts of the world. All are nearly allied to Deschampsia, but 
have the upper flower of each spikelet male with an awned glume, 
and the lower one unawned and hermaphrodite. Two Spanish 
‘species have been added by Boissier, ZT. grandiflorus and H. ces- 
pitosus; but as they have both the flowers hermaphrodite and 
awned (whence the sectional name Zomalachne), they should 
rather be transferred to Deschampsia, although they may have 
the peculiar soft habit of the common species of Holcus. 
7. Trıserum, Pers., is now known to comprise nearly fifty 
species, ranging over the temperate or mountain regions of both 
the New and the Old World. All are very near to the section 
Avenastrum of Avena, but differ generally in the flowering glume 
decidedly toothed at the apex, the two teeth often produced into 
