622 clvii. geamine^ (Stapf). [. Acroceras . 
(in Contr. U.S. Nat. Herb. xv. 325) enumerate it among the “ miscellaneous 
species.” 
It is interpolated here after Echinochloa more for technical reasons than on 
account of close affinity. The latter lies rather with Chloachne, which in the 
structure of the axes of the panicles and the laterally compressed herbaceous 
tips of the glumes and the lower valve and other particulars recalls Acroceras. 
It has, however, one peculiarity in common with Echinochloa, that is the 
curiously gaping tips of the fertile floret, due to the recurving of the thickened 
ends of the keels of the valvule. 
Perennial ; spikelets more or less oblong and plump. 
Blades broad-lanceolate from a suddenly constricted 
base, 3-5 in. by 4-9 lin. ... ... ... ... 1. A. oryzoides. 
Blades linear from a rounded or subcordate base, 2|-8 in. 
by 1^-4 lin 2. A. macrum. 
Annual ; spikelets more or less lanceolate. 
Culms simple or sparingly branched above the ascending, 
prostrate or floating base ; blades 3-12 in. by 
3-7£ lin., amplexicaul ; spikelets bluntly apiculate 3. A. amplectens. 
Culms much-branched below, forming loose leafy tufts 
from which the flowering culms rise ; blades 1-3 in. 
by 2-3| lin., flaccid ; spikelets subulate-apiculate 4. A. basicladum. 
1. A. oryzoides^ Stajpf7 Perennial, 2-4 (rarely to over 8) ft. high. 
Culms ascending from a branched prostrate or rambling or climbing 
and often rooting base, the erect parts simple or sparingly branched, 
the internodes of the base frequently strongly compressed, wiry, 
short or long and like the others very smooth and glabrous, the 
upper at length mostly somewhat elongated and exserted, sulcate or 
angular. Leaf-sheaths subherbaceous, tight, firm, terete, promi- 
nently striate, densely ciliate, otherwise quite glabrous and very 
smooth, rarely with a few hairs upwards ; ligules very narrow, 
membranous, ciliolate or almost suppressed ; blades lanceolate to 
lanceolate-linear from a broad suddenly constricted and rounded 
base, long-acuminate with a fine callous point, 3-5 (occasionally 7) 
in. by 4-9 lin., spreading, firm, flat, more or less greyish-green, 
glabrous or finely tomentellous and ciliate at the rounded base, 
smooth except along the scabrid finely cartilaginous margins, midrib 
fine below, primary nerves 3-6 on each side, distinct on both sides 
or at least below, with up to 7 secondary nerves between, which are 
connected by numerous minute cross- veins. Panicles erect, straight 
or nodding, at length more or less exserted, 3-10 in. long, made up 
(in the African specimens) of 4-7 suberect interruptedly spiciform 
or racemiform branches distantly disposed on a slender semiterete 
and facially flat or sulcate or upwards gradually subtriquetrous to 
triquetrous smooth common axis, branches villosulous at the very 
base, the longest half to two-thirds the length of the panicle, more or 
less triquetrous with scabrid lateral angles, a flat or subconvex back, 
up to J lin. wide, and a more or less broadly and bluntly keeled face, 
with upwards evanescent grooves on alternate sides of the successive 
internodes which are 2-2J lin. long, at its nodes bearing from the 
base or more rarely above it solitary or paired or scantily clustered 
