When Do Violets Bloom OR.

When Do Violets Bloom OR.

When Do Violets Bloom

Several species of Avena occur in the wild, sometimes as weeds in agricultural fields. They are known as wild oats or oat-grasses. Those growing alongside cultivated oats in agricultural fields are considered nuisance weeds, as, being grasses like the crop, they are difficult to remove chemically; any standard herbicide that would kill them would also damage the crop. A specific herbicide must be used. The costs of this herbicide and the length of time it must be used to reduce the weed is significant, with seeds able to lie dormant for up to 10 years.


Avena Linn., Sp. Pl. 1:79. 1753. Gen. Pl., ed. 5, 26. 1754; Malzew in Bull. Appl. Bot. Gen. Pl. Br., Suppl. 38. 1930; Bor, Fl. Assam 5:129. 1940; Sultan & Stewart, Grasses W. Pak. 2:280. 1959; Bor, Grasses Burma Ceyl. Ind. Pak. 432. 1960; Bor in Towns., Guest & Al-Rawi, Fl. Iraq 9:327. 1968; Bor in Rech.f., Fl. Iran. 70:322. 1970; Zohary in Davis et al., Plant life in South-west Asia, 235-263. 1971; Tzvelev, Poaceae URSS 236. 1976; Baum, Oats: Wild and Cultivated 1977; Rocha Afonso in Tutin et al., Fl. Fur. 5:206. 1980.The mode of disarticulation of the rhachilla is an important character in Avena, particularly as to whether it breaks up between the lowest and second lemmas. If it does so, then the articulation can easily be seen as an oblique line from the side and as a bearded horseshoe-shaped join in face view. In non-disarticulating spikelets there is no such join and the rhachilla internodes are shorter and stouter.

oats, (Avena sativa), domesticated cereal grass (family Poaceae) grown primarily for its edible starchy grains. Oats are widely cultivated in the temperate regions of the world and are second only to rye in their ability to survive in poor soils. Although oats are used chiefly as livestock feed, some are processed for human consumption, especially as breakfast foods. The plants provide good hay and, under proper conditions, furnish excellent grazing and make good silage (stalk feed preserved by fermentation).Oat (Avena sativa) is one of a number of species of domesticated and wild oats in the genus Avena (the members of which are collectively known as oats). Oat is descended from A. sterilis, a wild oat that spread as a weed of wheat and barley from the Fertile Crescent (a region spreading from Israel to western Iran) to Europe. It was domesticated about 3,000 years ago, in the wetter, colder conditions of Europe, in which oats thrive, and soon became an important cereal in its own right on the cooler fringes of Europe. (Source: powo.science.kew.org)



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