MR. G. BENTHAM ON GRAMINE. 953 
genus some species of Zsachne have been referred, but from which 
they constantly differ in the empty glumes persistent below the 
articulation, and in the two flowers both hermaphrodite or female, 
though one may be occasionally sterile. Graya, Nees (judging 
from the reference to Wight, but not from Steudei’s characters) 
is Isachne pulchella, Roth (Panicum bellum, Steud., P. malaccense, 
Trin.. Panicum Gardneri, Thw., which, as the author observes, 
is closely allied to Isachne Walkeri, Wight, appears to me to be 
strictly congener with that species, although one of the flowers of 
the spikelet is frequently, but not always, sterile. It scems to be 
the same as Zsachne nilaghirica, Hochst. 
3. ZENKERIA, Trin., very well described and figured in the 
‘Linnea,’ vol. xi., now contains two species from the East-Indian 
peninsula and Ceylon, both very near Jsachne, but with membra- 
nous fruiting glumes. Amphidonaw Heynei and A. tenella, Nees, 
do not differ from the typical Z. elegans, Trin. The second spe- 
cies is Z. obtusiflora (Amphidonax obtusiflora, Thw.). The ori- 
ginal genus Amphidonax of Nees was founded on a species of 
Arundo. 
4. Micratra, F. Muell., is a single North-east Australian spe- 
cies recently figured in Hooker's Icones. 5. CaracnwE, Br., 
comprises three East-Indian, Chinese, or East-Australian species— 
C. pulchella, Br., C. perpusilla, Thw., and C. simpliciuscula, Munro 
(Jsachne simpliciuscula, Wight et Arn.), which, as above observed, 
are anomalous in the tribe by a slight extension of the rhachilla 
between the flowering glumes. 6. Arropsıs, Desv., restricted to 
the single West-Mediterranean 4. globosa, is a pretty little 
annual, formerly placed in Milium on account of the hardening 
of the glumes, or in Aira, which it resembles in many respects. 
It shows, however, all the characters of Isachnes, and is indeed 
technically nearly allied to Zsachne itself ; but the two semiglobose 
fruiting glumes, closely appressed to each other by their flat 
faces, give the spikelets the peculiar globular shape expressed by 
the specifie name. 
7. ERTACHNE, Br., comprises twenty-two species, two of them 
endemie in tropical Asia, the remainder Australian, of which one is 
also in East India. They differ from Jsachne generally in their 
rather larger spikelets, and especially in the long hairs on the back 
or margins of the flowering glumes, and sometimes in the fine 
straight awns terminating the flowering glumes, or even the teeth 
ofthe pales. Megalachne, Thw. (not of Steud ), is Eriachne triseta, 
LINN. JOURN.—BOTANY, YOL. XIX. I 
