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Sorghum halepense - Johnsongrass

Scientific Family
Poaceae
Synonyms
Holcus halepensis, Sorghum miliaceum
Plant type
Grasses
Riparian
No

Grass Description

Origin
Introduced
Season
Cool
Warm

Common as a weed in ditches, cultivated fields and wastelands.

Plant Community
Disturbed Areas
Low elevation
0
High elevation
5500

General Description

Large lush green and aggressive sod grass, 3 to 6 feet tall, growing from wide spreading scaly rhizomes. Large open and spreading seedheads.

Large perennial, stout, scaly rhizomes. Leaves flat with white margins and prominent white midveins. Ligules are hairy. Seedhead is large, densely flowered, reddish. Spikelets paired, one fertile, sessile, awned, one stemmed and sterile. Awn is once-bent.

Grass type
Perennial bunchgrass
Rhizomes
Yes
Stolons
No
Clump Diameter 2 ft or more
No
Bushy - highly branched
No
Height with Seedheads
Greater than 36 inches
Seedhead Structure
Branched - open and spreading
Seedhead droops
No
First bloom month
April
Last bloom month
November

Flower Characteristics

Flowers per Spikelet
Multi-flowered
Spikelets One-Sided
No
Awns
Less than 1/4 inch
Three Awns
No
Awns bent
Yes
Flower and Seedhead Notes

Branched pyramidal seedhead consisting of 2 to 7 pairs of spikelets. Pairs of spikelets; one sesile and perfect-flowered, fertile and awned, but awn falls off readily; one stemmed, staminate, and not awned. Seeds are conspicuously black or red.

Vegetative Characteristics

Blade is hairy
No
Blade margins white
Yes
Blade cross-section
Flat

Blades 4 to 32 inches long, up to 1-1/2 inches wide. Large, flat and broad, prominent white mid-rib.

Sheath is hairy
No
Tufts of hair top of sheath or collar
No
Ligule
Membranous and hairy
Auricles
No

Moderately palatable and nutritious but may be toxic when prussic acid accumulates.