The plants are coarse perennials. The stems are 50-150 cm tall, from
extensively creeping scaly rhizomes; nodes are pubescent, internodes glabrous.
Leaf blades are mostly less than 2 cm wide and up to 60 cm long, pubescent
on the upper surface. The panicles are up to 60 cm long and 20 cm broad.
The fruits have a deciduous point, 1-1.5 cm long, which is twisted below.
Plants form coarse rhizomes finally occurring in dense stands. They grow
in fields, along roadsides and in waste places essentially throughout
the U.S. The leaves are often splotched with purple, due to a bacterial
Both true sorghums (Sorghum vulgare Pers.), which are annuals,
and Johnson grass sometimes produce hydrocyanic acid in sufficient abundance,
especially in second growth, to cause poisoning in grazing animals. Plants
have become troublesome weeds through most of the U.S.