Smooth Brome, Pumpelly's brome
Bromus inermis

Family: Poaceae or Gramineae

What it is like

Bromus inermis is a PERENNIAL growing to 1.2 m (4ft). See above for USDA hardiness. It is hardy to UK zone 3. It is in flower in May, and the seeds ripen from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil.

Height (m): 1.2

Where it is found

Not known

N. Europe, eastwards to China.

Conservation Status: This taxon has not yet been assessed.

Countries/locations it is found in

How it is used

Food

Rating: 0

Medicine

Rating: 0

Other

Rating: 2

An excellent plant to grow for controlling soil erosion because of its fast-growing interlocking root system. It is especially valuable in semi-arid regions, such as the Prairie Provinces of Canada and the Great Plains of the United States. Growth starts early in spring with a further period of growth in early autumn under favourable moisture conditions.

Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.

How it is grown

Best adapted to regions with moderate rainfall and moderate cool summer temperatures, it is suited to silt or clay soils and deep loams, but also does well on light sandy soils and on well-drained soils. Plants are less drought resistant than crested wheatgrass and they do not tolerate temperature extremes. Smooth brome is suited for irrigated areas but is not recommended for saline or alkali soils. Smooth brome is reported to tolerate an annual precipitation of 32 to 176cm, an annual average temperature range of 4.3 to 19.9°C and a pH in the range of 4.9 to 8.2. Smooth brome is also reported to tolerate alkali conditions, disease, drought, frost, fungi, grazing, mycobacterium, salt, viruses, and weeds.. There are a number of named varieties, selected mainly as hay and pasture crops. These cultivars are divided into two groups, northern and southern. The southern group is less cold-hardy and does not survive average winter conditions further north than southern Minnesota in N. America, the northern group is much more cold tolerant. The genus Bromus contains many complex, polyploid series. Bromus inermis belongs to section Bromopsis, containing wild species with chromosome numbers ranging from 2x to 8x. Following its introduction to North America, smooth broome, an aggressive species, has tended to replace native American species of sect. Bromopsis, especially B. pumpellianus. Hybridization studies have been made between: B. inermis, 8x; B. pumpellianus, 8x; and material of the introduced B. erectus complex (6x, 8x, 10x, though the last is probably itself hybrid). An objective of these studies was to incorporate into inermis the larger seeds of pumpellianus and better seedling vigour of erectus. The three species are related, crossable and give quite fertile hybrids. Collections of B. inermis in North America show varying meiotic irregularity and aneuploidy. This is probably a result of introgression from B. pumpellianus and the B. erectus complex. Quite a high degree of meiotic irregularity may be tolerated under natural conditions in a long lived, cross- pollinated species such as B. inermis, which can spread aggressively by rhizomes.

Propagating it: Seed - sow spring in situ. The seedbed should be firm and seed should not be covered to more than 6 - 13 mm depth. Seed rates of 3.3 kilos per hectare are used when the plant is sown in a pure stand, though it is more often sown in a mixture with various legumes such as alfalfa, sweet clover, red clover or Lotus corniculatus. There are approximately 300,000 seeds per kilo.

Best place to grow: Meadow; Cultivated Beds;

Habit: Perennial

Hardiness: 3-7

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Dry, moist

Things to keep in mind

This plant can be weedy or invasive.

Its other names

Local names

Arctic brome, Pumpelly's brome (subsp. pumpellianus), Austrian bromegrass, Russian bromegrass, awnless brome, Hungarian brome, Hungarian bromegrass, smooth brome, smooth bromegrass, (subsp. inermis). French: brome inerme, brome sans arêtes. German: unbegrannte Trespe, wehrlose Trespe. Portuguese: capim-cevadilha. Spanish: bromo de Hungría.

Synonyms

Bromopsis inermis (Leyss.) Holub. Bromus erectus Ledeb. [Invalid]. Bromus glabrescens Honda.