Bromus purgans.

Botanical name: 
Bromus kalmii

BROMUS PURGANS, L. Broom Grass. Medical grass, sudorific, vermifuge, laxative, diuretic, menagogue, &c. Excellent for cattle, purges them.

Medical Flora, or Manual of the Medical Botany of the United States of North America, Vol. 2, 1830, was written by C. S. Rafinesque.