Elymus repens Common Couch

A coarse, far-creeping perennial grass which grows on waste ground and cultivated land such as arable fields, allotments and gardens where it can be become a tenacious and often troublesome weed. In Grasses of the British Isles (BSBI Handbook No. 13, 2009), Tom Cope and Alan Gray describe it as one of the world's worst perennial weeds. It is quite variable but usually hairless and with many-flowered spikelets arranged alternatively in two rows on opposite sides of the stem. A maritime form of it that grows in open ground in coastal habitats, that has been variously named Elymus repens ssp. arenosus, Elymus repens ssp. littoreus and Elytrigia campestris ssp. maritima, is probably best regarded as just a variety of Elymus repens. It is often confused with Sea Couch (Elymus athericus), which is a very common maritime grass, differing from it by the absence of cilia on the edges of the leaf sheaths. This key character requires close inspection of young specimens for safe identification. Common Couch is widespread in West Glamorgan mostly as a weed of cultivated and waste ground. The status and distribution of the maritime form is uncertain.

Native