405 
Tmchypogon.] clvii. gkamine;e (Stapf). 
This polymorphic and apparently somewhat plastic species occurs in Africa 
in several forms of uncertain status, closely corresponding to analogous con- 
ditions in its American area (from Texas and Arizona to the Argentine). One 
form is vicarious of, if not identical with Trachypogon secundus, Scribn. ( Hetero - 
pogon secundus, Presl) and represents, if of short stature and with short racemes 
(2-3J in. long), the T. capensis of Trinius, whilst the other, taller and with 2-3 
racemes, corresponds similarly to the original T. plumosus, Nees ( Andropogon 
plumosus, hA. B. & K.) which, first described from Venezuela, is now known to 
extend from Colombia and Trinidad southwards to beyond the tropic. However, 
1-racemed states have also been collected in Brazil, so that the areas of the 
two forms overlap there, provided that these 1-racemed states are not merely 
reduced conditions of the typically several-racemed T. plumosus. That such 
occur is evident from specimens with 1- and several-racemed culms on the same 
stock. Conversely, T. secundus and its African parallel may occasionally produce 
a second or third raceme when they become indistinguishable — at least in 
the herbarium — from the original T. plumosus. Another character, namely the 
length of the ligule (from 1-15 lin.), might be expected to indicate a specific 
differentiation ; but it appears to be equally subject to fluctuation without 
any correlation to other characters or connection with the vigour of the indi- 
vidual or with geographical distribution. Thus, in the present state of our 
knowledge, practically nothing is left for taxonomic discrimination within this 
group. No attempt has therefore been made in this place to define varieties, 
but the specimens with more than 1 raceme per peduncle have been marked 
with an asterisk. The nomenclature of this species is controversial to some 
extent. Here, T. plumosus is extended so as to cover T. Montufari of Fournier 
(Mex. Gram. 65) and of Hitchcock (Mex. Grass, 198) — but not Andropogon 
Montufari, H. B. & K., which seems to deserve the rank of a distinct species — 
T. secundus of Scribner (U.S. Dept. Agric. Agrost. Circ. no. 32) and other 
American forms, and T. capensis, Trin. 
4. T. durus, Stapf. Perennial, compactly caespitose. Culms 
densely coated at the base with the firm persistent basal leaf- sheaths 
or their remains, up to over 3 ft. high, terete, glabrous except the 
upper ends of the internodes (either all or all but the lowest) which 
bear an annular beard of appressed hairs covering the contracted 
base of the sheath. Leaf-sheaths firm, terete, tight, produced at 
the mouth into short or obscure auricles, the intermediate and upper 
much shorter than the internodes, glabrous, smooth ; ligules firm, 
very short to almost 1 lin. long, obtuse, adnate to the auricles of the 
sheath ; blades junciform, convolute, wiry, rarely at length opening 
out, over 1 ft. long and under J lin. in diam., when flattened out 
under 1 lin. wide, glaucous-green, glabrous or shortly hairy or bearded 
behind the ligule, smooth, midrib very slender in the upper part of 
the upper side, stouter and more raised downwards, then flatter and 
much widened towards the base, quite obscure on the back, primary 
lateral nerves 1 or 2 on each side, prominent above. Racemes 
solitary, stiff, 4-5 in. long ; rhachis terete, glabrous or very sparingly 
hairy, shortly bearded along the very oblique disarticulation marks, 
internodes 2|— 3 lin. long ; longer pedicels 2J-3 lin. long, glabrous 
or sparingly hairy. Subsessile spikelets narrowly linear-oblong, 
hardly widened upwards, 4i lin. long, loosely hairy in the lower part, 
at length quite glabrous. Glumes equal ; lower coriaceous, convex 
on the back, obtuse, keels marginate or very narrowly winged upwards 
