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Johnson Grass

GRASSES

GENUS/SPECIES


Sorghum halepense

FAMILY


Poaceae
(includes all the grasses, including grains)

SYNONYMS


Common: Johnsongrass

DISTRIBUTION


Southern two-thirds of US

  • Central Nevada eastward through Nebraska
  • Nebraska eastward to S Michigan and Massachusetts
  • Massachusetts southward to S Florida
  • S Florida to S Texas to SE California
  • SE California to central Nevada
  • Hawaii

Comments

Johnson grass is a rather large perennial grass introduced from the Mediterranean region that is related to the commercially-grown sorghum. It can get to be as tall as eight feet but is usually less than six. Leaves may reach 20 inches in length with a distinct white midvein, and may approach an inch in width. The flower head rather suggests a corn tassel but of more delicate proportions. Blooming is typically in late spring or early summer. Johnson grass attains its best development in warm regions and in rich moist soil. Reproduction can be achieved by seed or by aggressive vegetative spreading of underground rhizomes. This grass is one of the important “southern grasses” from the standpoint of allergy.