Colorado Agricultural College 
its entire length or tipped with hairs; base of seed hairy at the point of 
Irticulation; seeds 2.5-8 mm. long, with a silky or downy appearance through- 
out. 
Key to Species 
. 4 , 1 ... 1 A. scopanus 
Rachilla hairy near the tip, flattened •••••••*.••• ^ A furcatus 
Rachilla hairy along its entire length, cylindrical 2 A. furcatus 
1. Little Bluestem, Broom Beard 
Grass (Andropogon scoparius Michx.) 
(Fig. 24). — Seeds chocolate to wamut 
brown in color, 5-7 mm. long, 1-1.5 mm. 
wide, slender; awn twisted and bent; 
seeds hairy at the base and near the 
tip of the rachilla. 
2. Big Bluestem, Forked Beard 
Grass {Andropogon fw'Ctttus L.) (Fig. 
25 ). — Seeds py rite-yellow to chocolate 
color, 6-8 mm. long, 1.5-2 mm. wide, 
stout ; awn straight, hair-like ; seed and 
rachilla hairy throughout. 
Fig. 24 
Bluestem 
ropogon 
ius). X 3. 
Little 
( And- 
scopar- 
Fig. 25 
Bluestem 
ropogon furcatus). 
X 21/4. 
(And 
9. Oat Grass 
{Avena (Tourn) L.) 
Lemma 5-9 veined, hardened except toward the apex which is bidentate 
(having two teeth) ; lemma bearing a long dorsal awn (either straight or 
wantinl in cultivated forms); palet papery, two-cleft at the apex, hairy at 
the base; rachilla cylindrical, slender, hairy, about one-fourth the 
the seed; seed 8-15 mm. long, 1-3 mm. wide, hairy at the base which usua > 
appears a perfect ring or sucker-like mouth with a tuft of hairs s~^^^ 
ing it; grain 2-7 mm. long, 1-2.5 mm. wide, hairy at the top and distinctly 
grooved. ^ 
1. Wild Oat (iuASs {Avena fatua 
L.) (Fig. 26).— Seeds walnut-brown to 
straw-yellow in color, 10-15 mm. long 
1. 5-2.5 mm. wide; rachilla hairy ; lemma 
with a sucker-like mouth at the base; 
dorsal awn, when present, stout, 
twisted, and bent. 
Fig. 
26. Wild Oat 
fatua). X 
Grass (Avena 
4. 
