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Panicum virgatum - switchgrass

Scientific Family
Poaceae
Synonyms
Eatonia purpurascens, Ichnanthus glaber, Milium virgatum, Panicum buchingeri, P. giganteum, P. glaberrimum, P. ichnanthoides, P. kunthii
Plant type
Grasses
Riparian
Yes

Grass Description

Origin
Native
Season
Warm

Sandy or rocky soil, mostly along water courses or in moist canyons.

Plant Community
Riparian
Low elevation
3500
High elevation
7000

General Description

Erect clumping grass from hard, scaly rhizomes, to over 6 feet tall. Seedhead is an open, branched arrangement of spikelets.

Rhizomatous perennial. Seedhead stems rarely branching above the base; spikelets more than 1/8 inch long and rounded; first glume more than half as long as the spikelet.

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

Flower Characteristics

Flowers per Spikelet
Multi-flowered
Spikelets One-Sided
No
Awns
Absent
Three Awns
No
Awns bent
No
Flower and Seedhead Notes

The seedhead is open, freely branched, pyramidal, 8 to 16 inches long. Spikelet is slightly laterally compressed, lower floret sterile, upper fertile.

Vegetative Characteristics

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

Blades firm, upright, spreading or ascending, to about 1-1/2 feet long, to 3/4 inch wide, linear with a rounded to slightly tapering base, flat, parallel-veined, sometimes hairy, marginally rough.

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

Switchgrass is noted for its heavy growth during late spring and early summer. It provides good warm-season pasture and high quality hay for livestock.