June 12, 2015

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

Life cycle

Rhizomatous perennial.

patch of johnsongrass
Patch of Johnsongrass.


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.


Very prominent, jagged, membranous ligule.


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.


Seeds and rhizomes.

johnsongrass rhizome section
Johnsongrass rhizome section.

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