Cheat grass

(Bromus tectorum L.)




Synonyms
Description
Cheat grass is a winter annual grass, low to moderately tall. The culms are erect, but weak, its leaves either smooth or pubescent. Its panicle has slender flexuous branches.
Distribution and habitat
Cheat grass originated in Eurasia and came to our area in contaminated seed in the 1890s. By 1920, cheat grass, or downy brome as it also is known, had invaded the semi-arid grasslands and open pinyon-juniper woodlands of the Colorado Plateau.
General information
Despite its early growth and rich color, cheat grass is unpalatable to sheep and other livestock, which tend to overgraze native plants when it begins to prevail. Most native bunchgrasses of the Colorado Plateau are perennial, whereas annual plants li ke cheat grass grow from a seed, then flower, set seed, and die every year. Cheat grass usually germinates in fall and grows during winter, opposite the cycle followed by common native perennial grasses. By the time the rain stops in spring, cheat grass a lready is maturing its seeds. Unlike native bunchgrasses, cheat grass then dies by the end of July, avoiding the hottest and driest part of summer. Because cheat grass quickly develops a large root system in the spring by the time native grass seedlings s tart to grow in April or May cheat grass has stolen most water out of the top foot of soil. Although mature native grasses can get water from lower soil regions, seedlings cannot get their roots deep enough into soil to access water before drought sets in , and thus, die of thirst. Without this ability to reproduce, native grasses inevitably decline, and so over time, cheat grass becomes more and more common until eventually it dominates. Cheat grass often opens the way for secondary invaders such as knapw eed and thistle.