''Hesperostipa comata'', commonly known as needle-and-thread grass, is a species of

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...

native to North America, especially the western third. It has a wide distribution spanning from northern Canada to Mexico.

Description

''Hesperostipa comata'' is a perennial

bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perenni ...

producing erect, unbranched stems to about in maximum height. The narrow

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

is up to long in taller plants, with the mature spikelet bearing a spiraling, hairy, spear-shaped awn up to in length. The seeds of this grass have hygroscopic extensions that bend with changes in humidity, enabling them to disperse over the ground. Each seed has an awn that twists several turns when the seed is released. Increased moisture causes it to untwist, and, upon drying, to twist again, thus the seed is drilled into the ground.

Habitat

This is a grass of many habitat types, from grassland to pine forest. Young shoots provide a favored food source for black-tailed prairie dogs and

black-tailed jackrabbits The black-tailed jackrabbit (''Lepus californicus''), also known as the American desert hare, is a common hare of the western United States and Mexico, where it is found at elevations from sea level up to . Reaching a length around , and a ...

, and the grass is a good early spring graze for livestock before it develops its long, sharp awn.

Cultural

This species was described by the explorers during the

Lewis and Clark Expedition The Lewis and Clark Expedition, also known as the Corps of Discovery Expedition, was the United States expedition to cross the newly acquired western portion of the country after the Louisiana Purchase. The Corps of Discovery was a select gr ...

. Needle and thread grass is the provincial grass of the prairie province of

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

. This species is popular among children because of the seed's ability to be thrown and stick to clothing. Image:Needleandthreadgrass1.jpg Image:Needleandthreadgrass3.jpg

References

External links

Jepson Manual Treatment - ''Hesperostipa comata''
* {{Taxonbar, from=Q15296074 Pooideae Bunchgrasses of North America Native grasses of the Great Plains region Native grasses of California Native grasses of Nebraska Native grasses of Oklahoma Native grasses of Texas Grasses of the United States Grasses of Canada Grasses of Mexico Flora of Northwestern Mexico Flora of the Western United States Flora of the Sierra Nevada (United States) Flora of the Great Lakes region (North America) Flora of Saskatchewan Natural history of the California chaparral and woodlands Provincial symbols of Saskatchewan Fiber plants Flora without expected TNC conservation status