Bromus madritensis is a species of brome grass

Bromus

Bromus is a large genus of the grass family . Estimates in the scientific literature of the number of species have ranged from 100 to 400, but plant taxonomists currently recognize around 160–170 species...

 known by the common name compact brome.

It is native to Europe but it has been widely introduced

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 elsewhere, such as North America, where it is found in many areas. It is now known nearly worldwide. This is an annual grass growing solitary or clumped stems to maximum heights between 10 and 50 centimeters. The panicle inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 holds spikelets with long awns which vary in color from green to distinctly purplish-red. The species is resistant to dry conditions.

There are two subspecies:

• B. m. ssp. madritensis: panicles less dense, stem and leaf sheath less hairy
• B. m. ssp. rubens (syn.
  Synonym (taxonomy)
  In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
  
  Bromus rubens) - foxtail brome, foxtail chess, red brome: dense panicles and slightly hairy stems

External links

• Jepson Manual Treatment
• USDA Plants Profile
• Kew GrassBase Profile
• Ecology and Taxonomy
• Photos: ssp. rubens