605 
Echinochloa .] clvii. gramine^j (Stapf). 
Species about 20-25, in the warm regions of both hemispheres. 
The segregation of the numerous forms which make up the genus Echinochloa 
and their reduction to more or less well definable species is still unsatisfactory, 
mainly owing to their apparently endless variability and the difficulty, if not , 
impossibility, of discriminating between stable and unstable modifications and 
the effects of hybridisation. Here, as in other cases, observation in the field 
and experiment will have to decide. For this reason no attempt at describing 
varieties has been made in this place. To have done so would probably have 
le^i to the establishment of many units without any stable basis. 
glume and up-per Valve equally obtuse or acute or 
cuspidulate ; false spikes 3-4-ranked, mostly short, 
suberect or erect and more or less appressed to the 
common axis, rarely spreading. 
Spikelets very obtuse, scaberulous towards the tips only, 
the nerves of the glumes becoming very obscure 
below them ; ligule represented by a line of fine 
hairs ... ... ... ... ... ... ... 1 . E. obtusiflora. 
Spikelets acute to cuspidulate or apiculate. 
Ligule represented by a fringe of hairs ; false spikes 
usually appressed to the common axis, 4-9 lin. 
by 3 lin. ; glumes very thin, pubescent and woolly - 
ciliate ; perennial ... ... ... ... ... 2. E. Holubii. 
Ligule 0 ; false spikes usually suberect, not appressed 
to the common axis, 6-12 lin. by 2 lin. ; glumes 
membranous, minutely rigidly and appressedly 
luihh pubescent between the nerves, eciliate ; annual 3. E.colona. 
Lower glume and upper valve cuspidate or produced into 
an awn, the latter more so than the former ; false 
spikes suberect or spreading. 
Ligule 0, the region of the junction of blade and sheaths 
discoloured inside, very finely pubescent or glabrous. 
Annual. 
Spikelets 1| lin. (excluding the cusp or awn) in 
generally simple false spikes, cuspidate or more 
or less awned from the lower floret ; a weed ... 4. E. Crus-Galli. 
Spikelets lin. (excluding the cusp or awn), 
abruptly caudate -acuminate or rostrate or 
(from the lower floret) aristulate, very densely 
clustered in compound false spikelets leaving 
a pinnate skeleton of axes after their fall ; 
usually stout stems 5. E. Crus-Pavonis. 
Perennial ; spikelets 1-1 1 lin. long, cuspidate or 
shortly awned (awn 3-4 lin. long), in simple false 
spikes ; sometimes tall with stout stems ... 6. E. haploclada. 
Ligule represented by a distinct fringe of hairs (some- 
times more or less reduced or suppressed in the 
uppermost leaves). 
Spikelets acute or shortly cuspidate, always awnless, 
li-2 lin. long, in usually large dense panicles with 
numerous straight obliquely erect false spikes ; 
perennial, tall, reed-like ... ... ... ... 7. E. pyramidalis. 
Spikelets acuminate, usually long-awned and if 
awnless 2-3 lin. long and in more or less distant 
frequently nodding false spikes. 
Spikelets ovate-oblong to lanceolate -oblong in 
outline, 2-3 lin. long (excluding the cusp or awn) ; 
