Johnsongrass

August 28, 2015

Sorghum halepense (L.) Pers.

Life cycle

Rhizomatous perennial.

Johnsongrass patch
Patch of Johnsongrass.

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.

Johnsongrass ligule
Johnsongrass collar region.

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.

Johnsongrass rhizome
Johnsongrass rhizome section.

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.

Johnsongrass seedhead
Johnsongrass seedhead.

Reproduction

Seeds and rhizomes.

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