The rump is boneless, or the fireless boneless (Bromopsis inermis (Leys). Holub (Bromus inermis Leys.)
Perennial with a long rhizome. Stem 60-100 cm high, highly leafy, at the base with sheaths of dead leaves, whole or partly split into simple fibers. Leaf blades 4-10 mm wide, dark green, often bare, sheaths closed, without ears, tongue 1 - 2 mm long. The inflorescence is a panicle, usually drooping, 15–20 cm long. Spikelets are large, 12–30 mm long, 3–12-flowered, the upper of the flowers is underdeveloped. Spikelet scales 5-8 mm long. The lower floral scales are dull, with a broad membranous edge, often purple on the back, without spine or with a short spine up to 4 mm long. Ovary and caryopsis at apex densely pubescent with short hairs. Grains 8-12 mm long, broadly lanceolate, dark gray or purple. The average weight of 1000 seeds is 3.5 g (see. Fig.).
Distributed in Europe, Asia Minor, northern and northwestern regions of Asia. One of the mass species in many areas of the USSR, except for the Arctic and the Far East, where it is found as an alien plant. It grows in meadows, river sands, along the banks of reservoirs, in clearings, in sparse forests and shrubs, along roads, along embankments. Resistant to prolonged flooding (up to 40-50 days). It tolerates overlapping with bulk up to 5-10 cm thick.
It prefers slightly acidic and neutral, well-drained, rich soils. It does not grow under anaerobic conditions, negatively reacts to the proximity of groundwater. It grows better in open and slightly shaded places. Frost resistant.
It usually dominates in the grass stand or is a co-dominant in natural meadow cenoses, most often foxtail and narrow-leaved nematic. Often forms a clean thicket. It reacts differently to species that grow with it. Oriental, meadow tea, meadow bluegrass and some other cereals and legumes have a sharp negative effect on it.
Propagated by seeds and vegetatively, and in natural cenoses, seed reproduction is apparently less important for the resumption of its populations. Seed productivity - up to 6-7 kg / ha. Their number per 1 m 2 can reach 18 thousand, but the number of seedlings in the cenosis is usually small, and only a few instances reach adulthood. Seed viability lasts up to 3-5 years, and then decreases sharply. Most of the seedlings appear in May - June. Tillering of seed plants occurs in the 3-4th year of an individual's life, and generative shoots form in the 4th to 5th year. The individual reaches its maximum development in the middle-aged generative period, having a high possibility for vegetative propagation and biomass production.
The annual renewal of vegetative shoots begins at the rump in late April - early May. In the same period, an inflorescence begins to form. Flowering shoots occurs in June - July and lasts until September. Flowering explosive and portioned. Individual panicles bloom 1 - 2 weeks, in dry weather - faster. The flowers of the upper spikelets are the first to open in the inflorescence, and the lower flowers in the spikelets. The bonfire blooms in the afternoon, between 15 and 20 hours. The duration of flowering of one flower is 2-3 hours. After falling to the ground, the seeds ripen for 8 months or more. Germination of fresh seeds is from 5-6 to 80-95%.