262 CHAPTER XV 



A vena ahyssuiica (Abyssinian Oats). — The lemma extends 

 into four teeth. Etheridge states that this group is grown 

 chiefly for forage in the desert regions of Abyssinia and 

 Southern Arabia. 



Avena strigosa (Rough or Sand Oats) and Arena hrevis 

 (Short Oats) are species often occurring wild in Europe, and 

 occasionally found cultivated there. They are of relatively 

 small importance. 



Aveyia fatua (Wild Oats) is of interest in that it is supposed 

 to be the progenitor of A. sativa and A. saliva orientaUs. The 

 seed is usually brown to black, the base and the rhachilla of 

 which are very hairy, and the lemmas are strongly awned. The 

 awn of the lower grain is very twdsted and right angular. The 

 panicle is very loose and of uneven maturity. The seed when 

 planted has a delayed and uneven germination. It is one of 

 the worst weeds found in winter cereals. 



Avena sativa (Common or Spreading Oats). — The majority 

 of cultivated varieties belong to this species. The panicle is 

 open and spreading, thus differing from Side Oats, and because 

 the lemma and palea remain attached to the caryopsis after 

 threshing, it can be distinguished from the hulless forms. 



Examples : Winter Dun, Boer Oats, Potato Oats, etc. 



Kvenu sativa orientaUs (Side or Mane Oats). — The panicle 

 is compacted and unilateral. The varieties of this species are 

 more restricted to localities and soils than Common Oats, 

 usually coarser strawed, smaller yielders, with a high percen- 

 tage of hull. The panicle is very apt to be broken off by wind. 



Examples : White Tartarian and Black Tartarian. 



General. — The colour of the glumes varies — white, black, 

 red, yellow or grey (dun) colours being commonly found. Spring 

 and winter oats are distinguished very sharply from each other 

 in the Northern Hemisphere. 



Early and late oats are found. Varieties vary in time of 

 maturity from 95 to 150 days, depending to a great extent on 

 the time of sowing. 



South African Varieties. 



Winter Dun or English Grey Winter.— A late variety 

 frequently sown for grazing ; if used for this purpose it should 

 be sown in March and not later than April. Tt is very well 

 suited to pasturing and has a spreading panicle and dun- 

 coloured grain. 



