free. It was once thought that all naked oats (the so- 
called species 4. nuda L..) came from China where hex- 
aploid naked oats are widely grown. The cytological work 
of Nikolaewa(1922)revealed that the small-grained naked 
oat was a diploid and undoubtedly European in origin. 
Later Mal’tsev showed A. nuda to be a highly diverse 
assemblage, containing, in addition to the present oat, 
four proles belonging to 4. sativa and one to A. byzantina. 
A. strigosa and its variants are the only diploid culti- 
vated oats and are geographically isolated from all other 
diploids except A. hirtula. Mal’tsev derived A. strigosa 
from A. hirtula, a judgment sounder than those of Thel- 
lung (1911, 1928) and Trabut (1914) who suggested the 
tetraploid 4. barbata had given rise to A. strigosa. De 
Candolle (1883) stated that 4. strigosa appeared to be a 
form of A. sativa, so subtle are the differences between 
the various cultivated oats. 
8. A. Wiestii Steud. = A. strigosa Schreb. ssp. Wiest 
(Steud.) Thell. A desert plant which is widespread in 
North Africa (Trabut, 1914), Egypt (Tiickholm et al., 
1941), Syria and Palestine (Post, 1933), Iraq and rare in 
eastern Transcaucasia (Mal’tsev, 1929). 
It is possible that both diploid and tetraploid oats exist 
which answer the description of 4. Wresta, but this will 
be considered later. Mal’tsev treats it as a tetraploid. 
Thellung (1911) and Trabut (1914) suggest that A. 
Wriestii is the wild species from which A. abyssinica has 
been derived, and in 1928 the former gave six transitional 
forms between the two. 
9. A. Vaviloviana (Malz.) Mordv. = A. strigosa 
Schreb. ssp. Vaviloviana Malz. =? ssp. Wiestit (Steud. ) 
Thell. var. pseudo-abyssinica Thell. A wild oat restricted 
to Abyssinia and Eritrea (Mal’tsev, 1929). 
[ 273 ] 
