Common name includes quaking-grass, common quaking grass, cow-quake, didder, dithering-grass, dodder-grass, doddering dillies, doddle-grass, earthquakes, jiggle-joggles, jockey-grass, lady's-hair, maidenhair-grass, pearl grass, quakers, quakers-and-shakers, shaking-grass, tottergrass, and wag-wantons.

B. media flowers from June to September in the UK, and is characterised by its fine stems and distinctive hops-shaped green and purplish spikelets.

The spikelets are 4 – 7 mm long, loosely scattered and drooping, laterally compressed and elliptic to ovate in shape.

[2] In North America, the species has been introduced and occurs in Connecticut, Massachusetts, Michigan, and Vermont in the USA, and in British Columbia and Ontario in Canada.

It is reported to be a poor competitor and therefore negatively impacted by a high density of neighbouring plants in unmanaged grassland.