Achnatherum robustum

Taxobox
name = Sleepy grass

---

image_caption = Line drawing of "Achnatherum robustum" from the USDA PLANTS database.
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Poales
familia = Poaceae
genus = "Achnatherum"
species = "A. robustum "
binomial = "Achnatherum robustum "
binomial_authority = (Vasey) Barkworth [cite web
last = USDA
coauthors = NRCS
title = The PLANTS Database
publisher = National Plant Data Center
date = 2007
url = http://plants.usda.gov
accessdate = 2007-08-07]

"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.

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.

When infected with an acremonium fungus, it contains lysergic acid amide (LSA). [Petroski RJ et al. "Alkaloids of Stipa robusta" PMID 1344912]

Its diacetone alcohol ingredient has a mildly toxic effect on cattle and livestock, causing drowsiness.

References