Achnatherum robustum

Achnatherum robustum, commonly known as sleepy grass, (synonyms Stipa robusta, also Stipa vaseyi subsp. robusta) is a perennial plant in the Poaceae or grass family.

Sleepy grass
Line drawing of Achnatherum robustum from Lamson-Scribner's American grasses (illustrated), 1899
Conservation status
Secure  (NatureServe)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Clade:	Commelinids
Order:	Poales
Family:	Poaceae
Subfamily:	Pooideae
Genus:	Achnatherum
Species:	A. robustum
Binomial name
Achnatherum robustum (Vasey) Barkworth[2]

Distribution

It grows on dry soil in the U.S. Midwest, ranging from South Dakota, Nebraska and Kansas, Wyoming, Colorado and New Mexico to Texas and Arizona, California and Hawaii.

Ecology

Sleepy grass plants harboring a fungal species (of the genus Neotyphodium), contain ergoline compounds, such as lysergic acid amide (common name, ergine). These compounds appear to be responsible for the sedative effects on mammals when they ingest the infected grass.^[3]