It is a grass which are easily confused with a plethora of many other grasses (poaceae).

Not to be confused with Broom (Cytisus scoparius) a bushy and much taller plant with yellow flowers.

Soft Brome exists as 5 slightly differing sub-species:

• (Bromus hordeaceus ssp. hordeaceus) which is often much shorter than 80cm, with a panicle usually less than 10cm long, with between a few to many spikelets which often droop to one side when mature. The lemmas (being the outermost of two bracts at the end - and the only one to have an long and narrow awn [aka spike] at the tip) are usually hairy, 8 to 11mm long and 3 to 5mm wide with a more or less straight awn (which are hair-like points at the tip) 4 to 11mm long but only ~0.1mm wide at its base. This ssp. is native and found in amongst grass, on waysides or rough ground and frequently occurs throughout lowland Britain.
• (Bromus hordeaceus ssp. molliformis) a non-native wool-alien casual neophyte which has stems up to 60cm high with a flower panicle less than 10cm long and with many stiffly-erect spikelets having very short branches and stalks. The hairy lemmas are 8 to 11mm long by 2.5 to 3.5mm wide with a 4-10mm awn which thickens to 0.2mm at the base and later curves outwards. Found in waste places and waysides.
• (Bromus hordeaceus ssp. ferronii) [RR] which has much shorter stems to 15cm (up to 20cm); with a panicle of spikelets which is less than 5cm long and with only a few spikelets on it; erect lemmas 6.5 to 8mm long and 4 to 5mm wide; and with awns 2 to 6mm long curving outwards when mature. It too is native and occurs on grassy cliff tops or sandy or shingly ground near the sea. Scattered intermittently on the coasts.
• (Bromus hordeaceus ssp. thominei) [RR] is considered by some authorities to be identical to ssp. feronii described just above! Otherwise; the somewhat woody stems are 8cm long (occasionally up to 12cm) and procumbent to ascending; the panicle is less than 3cm long with only a few erect spikelets; the lemmas are 6.7 to 7.5mm long by 4 to 5mm wide and usually hairless (or infrequently hairy); and their awns are 3 to 7mm long and either straight or slightly curved outwards. It is native and occurs in much the same habitats as ssp. ferronii. However it is often mistaken for the much taller (up to 60cm!) Lesser Soft-brome (Bromus × pseudothominei) which itself might be better put under the Hordeaceus genus as Bromus hordeaceus ssp. pseudothomnei! Oh the tortuous lives that taxonomists must endure!
• (Bromus hordeaceus ssp. longipedicallatus) which is the tallest Soft Brome sub-species being erect to 1.5m. The panicle is less than 20cm long and has many spikelets, some of which have long stalks and splay outwards; lemmas are 7.5 to 10.5mm long and usually hairy; Awn straight and 4 to 10mm long. This too is native, growing in grassy places , field edges, waysides and scattered over the British Isles but occurring mostly in the South.