may be divided into three subspecies: sterilis, trichophylla 
and Ludoviciana. 
Ssp. sterilis =ssp. macrocarpa (Moench) Brig. A stout 
plant with large grains, spikelets with 3-5 florets, glumes 
30-50 mm. long, culm-nodes glabrous. It is strictly 
Mediterranean in distribution (Mal’tsev, 1929). 
Ssp. trichophylla (C. Koch) Malz. A more slender 
plant with medium-sized grains, spikelets with 2-8 florets, 
glumes 25-85 mm. long, culm-nodes pubescent. It shares 
the easternmost range of ssp. stevi/is in Palestine, Syria 
and western Asia Minor, but it extends eastward through 
Asia Minor to Transcaucasia, western Iran and Iraq 
(Mal’tsev, 1929). Mal’tsev regards this subspecies as 
intermediate between ssp. sterilis and ssp. Ludoviciana. 
Ssp. Ludoviciana (Dur.) G. & M., is a plant with 
small grains, spikelets with 2 (rarely 3) florets, glumes 
25-830 mm. long, and glabrous culm-nodes. It ranges 
from southern England (Clapham et al., 1952), through 
France, Switzerland, Italy (Thellung, 1911), Spain 
(Willkomm and Lange, 1870) to North Africa (Battan- 
dier and Trabut, 1904). It is scattered throughout the 
Mediterranean region and becomes more abundant from 
Asia Minor through southern Russia, the Caucasus, 
southern Turkmenistan and northern Iran to Afghanistan 
and Turkistan (Mal’tsev, 1929). This subspecies, which 
has the general aspect of 4. fatwa, occurs largely in areas 
where the ranges of A. sterilis and A. fatua meet or 
overlap. 
Since the similarities between the two species were 
pointed out by Trabut (1914), it has been universally be- 
lieved that A. byzantina has been derived from A. steri- 
lis. Thellung (1928) has distinguished 15 transitional 
forms. Recently Coffman (1946) has proposed the theory 
that A. steriis is the progenitor of all other hexaploid 
oats. 
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