Definition
Bromus interruptus, commonly called interrupted brome, is a species of annual grass in the family Poaceae. It is native to the United Kingdom and is considered extinct in the wild.
Overview
Bromus interruptus was first described in the early 19th century and was historically confined to chalk grasslands and cultivated fields in southern England. The species declined rapidly after the early 20th century due to agricultural intensification, habitat loss, and the cessation of traditional land‑use practices. The last known wild specimens were recorded in the 1930s, and the plant was declared extinct in the wild by the International Union for Conservation of Nature (IUCN) in the 1970s. Conservationists have maintained seed collections, and limited re‑introduction attempts have been carried out in protected sites.
Etymology / Origin
The generic name Bromus derives from the Latin broma, itself borrowed from the Greek βρομός (bromos), meaning “oats,” reflecting the grain‑like appearance of the seed heads. The specific epithet interruptus is Latin for “interrupted,” referring to the characteristic discontinuous arrangement of the spikelets along the inflorescence axis, which distinguishes it from closely related Bromus species.
Characteristics
- Life form: Annual herbaceous grass.
- Growth habit: Erect culms reaching 30–70 cm in height.
- Leaves: Flat, linear leaves with a smooth to slightly rough (scaberulous) surface; ligules are membranous and short.
- Inflorescence: Open, lax panicle with spikelets spaced irregularly, giving an “interrupted” visual pattern; each spikelet contains usually three to five florets.
- Phenology: Flowers June to August in its native range; seeds mature by early autumn.
- Habitat: Historically found on calcareous (chalk) grasslands, disturbed soils, and the edges of arable fields.
- Conservation status: Extinct in the wild (IUCN); ex situ conservation achieved through seed banks and cultivated specimens in botanical gardens.
Related Topics
- Genus Bromus – a diverse group of grasses, many of which are widespread as weeds or pasture species.
- Chalk grassland ecosystems – biodiverse habitats of southern England that support numerous specialized plant species.
- Plant conservation and re‑introduction – strategies employed to preserve extinct‑in‑the‑wild taxa, including seed banking and habitat restoration.
- Agricultural intensification and biodiversity loss – historical processes contributing to the decline of many native grassland species in the UK.