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

Poaceae

The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...

 or grass family.

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 and Hawaii.

Sleepy grass plants harboring a fungal species (of the genus Neotyphodium

Neotyphodium

Neotyphodium is a form genus containing species of endophytic fungi. These endophytes are asexual, seed-borne symbionts of cool-season grasses, and grow intercellularly throughout the aerial tissues of their hosts, including shoot apical meristems, leaf sheaths and blades, inflorescences, seeds and...

), contain ergoline

Ergoline

Ergoline is a chemical compound whose structural skeleton is contained in a diverse range of alkaloids including a few psychedelic drugs . Ergoline derivatives are used clinically for the purpose of vasoconstriction and in the treatment of migraines and Parkinson's disease...

 compounds, such as lysergic acid amide (common name, ergine). These compounds appear to be responsible for the sedative

Sedative

A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....

effects on mammals when they ingest the infected grass.
It is also smoked by potheads who mix it in with their bud. But as soon as the ass holes in the whitehouse found this out. They got shi ttyheaded.