H. Lemma with 2 lateral teeth; awns not exserted 
J. Florets articulated, scar oval or round 
K. Awns at tip of lemma 3-6 mm. long 
A, Wiestii 
kK. Awns+1 mm. long A. Vaviloviana 
J. Florets not articulated; awns 1-4 mm. long 
A. abyssinica 
G. Lemma ending in 2 awns to 5 mm. long, lateral teeth 
wanting; glumes with 9(10) nerves; articulation-scar 
oblong A. barbata 
A. Lemma usually ending in two small teeth, never produced into 
two setiform awns; plants mostly robust; 2n=42 (Subsect. Den- 
ticulatae Malz.) 
L.. Lower floret articulated with the rachilla 
M. Upper florets not articulated, spikelet falling as a unit 
A. sterilis 
M. All florets articulated A. fatua 
L. None of the florets articulated, separated by fracture of rachilla 
N. Most of rachilla segment remains attached to upper floret 
on threshing; fracture surface at base of lower floret slant- 
ing A. byzantina 
N. Rachilla segment remains attached to lower floret; fracture 
surface not slanting A. sativa 
Distribution and Relationships of Avena Species 
1. A. clauda Dur. A wild oat found in Algeria 
(Battandier and Trabut, 1904), Tripoli, Palestine (Post, 
1983), Asia Minor, Iraq, Transcaucasia and eastward to 
Turkistan (Mal’tsev, 1929). Reported as rare in Attica, 
Greece (DeHalacsy, 1904). 
Mal’tsev says this species more closely resembles the 
genus Helictotrichon than any other Avena species. He 
therefore considers it to be the most ancient, and to have 
given rise to the remainder of the Aristu/atae through 
A. longiglumis. 
2. A. pilosa M. Bieb. A wild oat occurring in north- 
ern Algeria (Battandier and Trabut, 1904), Tripoli, Syria 
(Post, 1988), Asia Minor, the Caucasus and eastward to 
southern Turkmenistan (Mal’tsev, 1929). 
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