Japanese Brome (Bromus japonicus Thunb.)

Japanese Brome description

Japanese brome is an annual grass that can reach 1 m in height.

Propagation

Japanese brome reproduces by seed and can germinate over a wide range of temperatures. Requires moisture to germinate.

Similar species

Similar to Downy brome. It is very difficult to distinguish the two bromes in the seedling stage, but Japanese brome tends to grow in wetter sites than downy brome. Downy brome has an open drooping panicle with long straight awns attached to the seed. Japanese brome has a panicle with the spikelets borne at the ends of long branches. Japanese brome seed is somewhat shorter than downy brome seed and has a twisted awn. Downy brome seed is a reddish color at maturity while Japanese brome is tan in color. (source: Government of Alberta)

Distribution

Japanese brome exists across Canada.

Identifying Japanese Brome

Seedling

Seedling leaves narrow, twisted, with short and softly hairy ligules. Seedlings usually seen in fall (winter annuals).

Mature plant

Erect, slender, 14 to 30 inches tall at maturity, usually growing in clumps from the base.

With short, softly hairy ligules. Leaves and blades with soft hairs, leaves narrow.

Awns are 8-10 mm long and straight to bent/twisted at maturity. First glumes are usually 3- to 5- nerved and second glumes are 5- to 9-nerved. Lemmas are broader at the upper-half, tapering to the bottom, with margins not strongly enrolled.

Root structure description

Fibrous.

Flowers

Seed heads loose, one-sided, 4-1/2 to 8 inces long, with 3 to 5 lower drooping branches. Winter annuals flower in May and June. Annuals flower in August. Seeds with awns, in small spikes about 1/2 inch long. Awns 1/4 to 3/4 inch long.