Johnsongrass – Sorghum halepense

Johnsongrass patch

Johnsongrass patch

Johnsongrass ligule

Johnsongrass ligule

Johnsongrass seedhead

Johnsongrass seedhead

Johnsongrass rhizome

Johnsongrass rhizome

Johnsongrass

Sorghum halepense (L.) Pers.
Poaceae (Grass family)

Life cycle
Rhizomatous perennial.

Leaves
Bright green leaves are hairless with a prominent, white midvein. Leaves are rolled in the bud and may be up to 24 inches long. Leaf sheaths are also hairless.

Ligule
Very prominent, jagged, membranous ligule.

Stems
Erect, stout, hairless stems may reach 10 feet in height. Round to sometimes flattened stems are purple-tinted at the base. Plants form dense patches by purplish, thick, scaly rhizomes.

Flowers and fruit
The seedhead is a purple, very large, open and spreading, pyramid-shaped panicle that consists of numerous whorled branches. Seeds are oval, shiny and reddish brown.

Reproduction
Seeds and rhizomes.