About Hesperostipa comata (Trin. & Rupr.) Barkworth
Hesperostipa comata is a perennial bunchgrass that grows erect, unbranched stems reaching a maximum height of roughly 1 meter (3 feet 3 inches). In taller individuals, its narrow inflorescence can grow up to 28 centimeters (11 inches) long. Mature spikelets of this species bear a spiraling, hairy, spear-shaped awn that can reach up to 19 centimeters (7 and a half inches) in length.
The seeds of this grass have hygroscopic extensions that bend in response to changes in humidity, which allows the seeds to disperse across the ground. When a seed is released, its awn is twisted several turns. Increased moisture makes the awn untwist, while drying makes it twist again. This repeated twisting and untwisting drills the seed into the ground.
This grass grows in a wide range of habitat types, from grasslands to pine forests. Young shoots of Hesperostipa comata are a preferred food source for black-tailed prairie dogs and black-tailed jackrabbits. It also serves as good early spring forage for livestock, before it develops its long, sharp awn.
