Key characteristics

• Annual or perennial grasses, usually tufted, commonly with hairy leaf sheaths. Ligules membranous, leaf blades flat
• Fifteen species, mostly introduced from north temperate regions, have become naturalised. Five other species are considered transient, which means occasionally found in the wild but not persisting and therefore not fully naturalised. One species (Bromus arenarius) was formerly considered native to NZ but is now though to have been an early introduction from Australia
• Improved cultivars of some species (Bromus inermis, Bromus sitchensis, Bromus stamineus, Bromus valdivianus and Bromus willdenowii) have been bred for pasture use.

Most commonly found species

Bromus diandrus (ripgut brome)

• Tufted annual grass 20-90 cm high with a few large spikelets, each with sharp, rough, stiff awns
• Flower stems are leafy and bent over with the weight of the spikelets
• Leaf blade is flat with a finely pointed tip. It is 4-30 cm long and 5-7 mm wide, with short, scattered hairs and rough to the touch near the tip
• Ligule is membranous, jagged, 1.5 to 4 mm long. Leaf sheaths are tubular, rounded on the back, with soft short spreading hairs except near the bases of the upper sheaths
• Flower head is a loose nodding panicle variable in size, up to 25 cm long and wide, with branches up to 10 cm long in clusters of 2-4. These, spread unequally, are very rough and each carries one or two green or purplish spikelets
• Each spikelet has 5-8 flowers and is 5-10 cm long, including the awns
• Awns (long bristles on the flower head) are long and rough, and able to penetrate the mouths, eyes, skin or even the intestines of sheep grazing in infested paddocks
• Found on roadsides and waste ground throughout NZ, originally from Mediterranean areas.

Bromus hordeaceus (soft brome)

• Annual grass found throughout the country along roadsides and in waste land but also remarkably common in pastures
• Grows in grey-green tufts and is very variable in size, from 10-100 cm tall
• Leaf sheaths have long fine hairs, although upper sheaths are sometimes devoid of hairs
• Ligules are short, about 0.5-1.5 mm long, toothed, with short hairs on the back
• Leaf blade, 3-18 cm long and 1.5 – 5 mm across, is soft and velvety with short hairs
• Flower head has branches, each bearing one or several spikelets
• Each spikelet is 1.5 – 3 cm long, containing 4-12 individual flowers
• Awns are short (3-8 mm) and relatively soft
• Introduced from Europe or west Asia.

Bromus stamineus (spikey brome, grazing brome)

• Perennial grass, only found in the South Island, often along roadsides and in waste places, especially in low rainfall areas near the coast
• Improved cultivars of this species have been bred for pasture use
• Suited for grazing in dry East Coast areas, where it gives quality winter and summer feed
• 60-200 cm tall and described as having rather coarse leaves
• Leaf sheath has long silvery hairs
• Leaves are 16-40 cm long and 5-11 mm wide, with a few scattered fine hairs
• Flower head is stiffly erect when young and spreads more with age
• Spikelets are 2.5-4 cm long, with 7 or 8 flowers. Awns are 3.5-9 mm long
• Species introduced from South Africa.

Bromus sterilis (barren brome)

• Annual or biennial grass, found in a few places in Northland and everywhere south of Auckland in the North Island. Also found throughout the South Island, except in wetter western and southern districts
• Leaf sheath densely covered in short hairs, but upper sheaths may be hairless
• Leaves 6-25 cm long by 2-6 mm wide, rough at the margins and tips and with short, soft hairs
• Flower stem 25-55 cm tall, erect or sometimes kneed at the base
• Flower head 15-20 cm long, with few branches which are drooping and nodding, and 1 to 3 spikelets at the tips
• Spikelets large, 3.5-6.5 mm long, with 4-14 flowers
• Native to Europe, south-west Asia and North Africa.

Bromus tectorum (downy brome)

• Usually loosely tufted annual grass, with hairy leaf sheaths and leaves
• Leaves 1-14 cm long by 1.2 – 5.5 mm wide
• Flower stem 6-35 cm high, sometimes longer, slender
• Flower head 3.5-25 cm long, with very slender branches, usually nodding
• Spikelets light green to purplish, 2.2-3.5 cm long, with 4-8 flowers
• Only found near Onehunga in the North Island but common in Marlborough, Canterbury and Otago in the South Island. Grows on waste ground or modifies tussock grasslands.

Bromus willdenowii (prairie grass)

• Rather coarse, tall-growing (30-120 cm), perennial grass found throughout the North Island and South Island
• Found along roadsides, waste places and pasture
• Leaf sheath with a keel towards the top, and fine, silky hairs, especially in the lower sheaths
• Leaves 15-40 cm long by 8-15 mm wide, smooth or slightly rough on the ribs on the lower surface, and fine scattered hairs on the upper surface
• Flower stem stout, often very erect
• Flower head erect or nodding, 15-35 cm long, with branches in 2s or 3s at the nodes
• Spikelets 2-5 cm long, containing 5-9 flowers
• Originally introduced from South America.