Scientific name: Avena fatua L.

Common name:Wild oat(s)

Family: Poaceae

Origin:

Native of Europe and western and central Asia.

Habit:

Annual tufted grass growing to a height of 2 m in crops, but usually about 1 m tall.

Habitat:

A problematic weed in cereal crops. Also found along roadsides, railways and in other disturbed sites.

General description:

Stems and leaves

Stems (culms) can be erect or bent like a knee at the base. Leaves have ligules that consist of a membranous flap (up to 8 mm long), varying in shape from blunt to pointed and with irregularly toothed or cut (lacerate) margins. The leaf blades can be up to 45 cm long and 1.5 cm across. Leaf margins and veins may be rough to touch. Occasionally, leaves may have long scattered hairs.

Flowers and fruit

The inflorescence is a loose panicle 10-40 cm long. Flower spikelets hang from long stalks (pedicels), and are made up of one to three 'florets' partially enclosed in two large papery bracts (glumes). Once mature the spikelet readily separates (disarticulates) into separate 'florets', but the glumes usually persist. The glumes are hairless and the upper one is slightly longer than the lower one. Upper glumes range from 2-3 cm in size and lower glumes from 1.5-3 cm in size. The fruit consists of a seed tightly enclosed in two hairy and hardened 'bracts' (palea and lemma) and a large awn which is twisted and bent (2-4.5 cm in length). The seed itself (caryopsis) is almost cylindrical (sub-terete), has a frontal groove, and is elongated.

Distinguishing characteristics:

The two common types of wild oat found in Australia (ie. Avena fatua and Avena sterilis subsp. ludoviciana) and both are very similar. One slight difference between these two species can be found in the flower spikelets. The 'florets' of Avena fatua (wild oat) separate quite easily at maturity, while the florets of Avena sterilis subsp. ludoviciana (ludo wild oat) are attached to each other by short stems and do not separate from each other easily at maturity.

Noxious status:

Not noxious.

Sources:

Kleinschmidt, H.E., Holland, A. and Simpson, P. (1996). Suburban Weeds. 3rd Edition. Department of Primary Industries, Brisbane.

Stanley, T.E. and Ross, E.M. (1983-1989). Flora of South-eastern Queensland. Volume 3. Department of Primary Industries, Brisbane.