Anisantha diandra Great Brome

Anisantha diandra (Bromus diandrus), Great Brome, is a coarse, hairy annual grass up to 1m tall, with a lax inflorscence of relatively long spikelets which tend to spread or droop a little and with a long bristle (awn) attached to the tip of the lemma in each floret.  It is somewhat like a large version of Compact Brome (Anisantha madritensis) and small plants can be confused with it quite easily. Unfortunately, it is quite variable in size and the two species can only be distiguished with certainty after checking the lengths of the lemmas, which are the papery glumes found on the lower side of each floret in the spiklets. The lemmas of Great Brome are 20-36mm long while those of Compact Brome are 12-20mm long. Great Brome is a Mediterranean species which has been introduced widely outside its native range in Europe. In Britain it is a grain, birdseed and wool alien and although formerly rather scarce it has become more common in recent years. It grows in disturbed sites, open mosaic habitats and particularly on sandy soils, including the disturbed fringes of coastal dunes. There are scattered records from West Glamorgan, mostly coastal, and there is a significant population of it in Oxwich Dunes. There are 2 varieties of Great Brome, var. diandra and var. rigida. Only the former has been recorded in West Glamorgan.

Neophyte