130 
W. C. Etheridge 
fine; basilar articulation of the outer grain evident; rhachilla of the outer 
grain short (2-2.5 mm.), strong, glabrous, persistent to the inner grain. 
Plants 5-8 dm. tall; medium early in maturing. 
Specimens of the Burt variety were found under the following addi- 
tional names; Early Ripe, Red Rustproof, Unnamed. 
King (Plate IX, 2, and fig. 22) . — Culms semi-erect in early growth, 
otherwise similar to those of A. sterilis nigra; sheaths, leaves, panicles, 
spikelets, and glumes similar to those of A. sterilis nigra, except that the 
glumes are shorter, ranging from 20 to 25 mm., and usually have fewer 
nerves, 8 nerves being common, although 7 or 9 nerves may occur; grains 
dun-colored, somewhat elongate, outer grains 18-22 mm. long, long-pointed; 
lemma glabrous, with 7 obscure nerves; awn frequently present on the 
outer grain but rarely on the inner grain, seldom twisted; basal hairs 
wanting or seldom occurring; basilar articulation of the outer grain usually 
solidified, although occasionally the lines of articulation may be seen; 
rhachilla of outer grain short (2-2.5 mm.), strong, glabrous, persistent to 
the inner grain. Plants. 5-8 dm. tall; medium late in maturing. 
Avena abyssinica, according to Schulz (1913), is distinguished by the 
structure of its lemma, which extends into four teeth. Kornicke and 
Werner (1885) give a similar description. Schulz states also that in 
cultivated forms of A. abyssinica the basilar articulation of the grains is 
solidified; and Trabut (1911) notes a transition of this character between 
the wild and the cultivated forms, the wild forms having a fragile articu- 
lation, while in the cultivated forms the grains are retained. 9 The A. 
abyssinica form is grown in the desert regions of Abyssinia and southern 
Arabia, chiefly for forage. 
The closely related groups Avena strigosa and Avena brevis are distin- 
guished by the structure of the lemma, this having two teeth or awn 
points at the apex. A. strigosa has a lanceolate lemma which extends 
into distinct awn points, while the lemma of A. brevis is short, abrupt, and 
blunt, and is rather toothed than awn-pointed although in one form ti e 
AVENA ABYSSINICA 
AVENA STRIGOSA AND AVENA BREVIS 
»No specimens of A. abyssinica are included in the present classification. 
