Johnsongrass

June 12, 2015

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

Life cycle

Rhizomatous perennial.

patch of johnsongrass
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.

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 collar region
Johnsongrass collar region.

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
Johngrass seedhead.

Reproduction

Seeds and rhizomes.

johnsongrass rhizome section
Johnsongrass rhizome section.

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