638 
CLVII. GRAMINEA: (Stapf). 
[ Panicum ... 
70. PANICUM, Linn. 
Spikelets lanceolate to oblong, elliptic or orbicular in outline, 
symmetrical in profile, rarely somewhat oblique, falling entire or 
almost so, from the often elongated pedicels of a compound or de- 
compound panicle, without a definite orientation towards the axis ; 
lower floret g or barren, and then usually with a distinct valvule ; 
upper floret Glumes more or less herbaceous- membranous ; the 
lower usually shorter than the upper (often by very much), rarely 
equalling it, usually with 1 or more nerves or if very small nerveless ; 
upper as long as the spikelet, rounded on the back, 5-9-nerved. Lower 
floret : valve very similar to the upper glume and equally rounded and 
curved on the back (rarely less when the spikelets become oblique), 
5-9-, rarely 3- or 11 -nerved ; valvule thinly membranous to sub- 
hyaline, subequal to the valve or more or less reduced, rarely sup- 
pressed. Upper floret : valve subcoriaceous to coriaceous with firm 
margins, obtuse to subacute, emucronate (see 1, P. meyerianum), 
faintly nerved ; valvule subequal to the valve and of similar sub- 
stance, tightly embraced by the more or less involute margins of the 
valve. Lodicules 2, broadly cuneate. Stamens 3. Styles distinct ; 
stigmas laterally exserted near the tip of the floret. Grain tightly 
enclosed by the hardened valve and valvule, dorsally compressed, 
biconvex to almost plano-convex ; scutellum elliptic to ovate- 
elliptic, about half as long as the grain ; hilum subbasal, punctiform. 
— Perennial or annual, rarely suffrutescent, of varying habit and 
size ; leaf-blades mostly linear to linear-lanceolate, but in some 
groups ovate or filiform to subulate ; panicles usually much divided 
and at least temporarily open ; spikelets usually loosely scattered, 
glabrous or hairy. 
Species about 400, in the tropical and subtropical regions of both hemispheres, 
few in the warm-temperate regions. 
The sections adopted here are mainly based on the Old World and especially 
the African material. They appear to represent on the whole homogeneous 
groups, held together by a number of correlated characters which suggest 
genetic affinity ; only one or two of the smaller groups are somewhat unsatis- 
factory in this respect and may require revision when more material comes to 
hand. 
Key to the Sections. 
^ Spikelets symmetrical in profile (see § Monticolce) ; leaves 
not soft and at the same time very thin and ovate- 
lanceolate to ovate from a rounded and much con- 
stricted base. 
* Valve of lower floret more than 3 -nerved. 
jBlades typically much more than V-l-| in. long or, if 
not, then subulate-involute and pungent. 
J Spikelets over 1 £ lin. long or if smaller then different 
from those of § Monticolce (see below) and on 
plants of different habit. 
