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Weed Identification

switchgrass

Family

Poaceae

Scientific Name

Panicum virgatum

Habit

Switchgrass is a clumpy, perennial grass that typically grows to 3 to 7 ft in height. It spreads by rhizomes and forms loose clumps or patches.

Leaves

The leaves are flat, 0.5 inches wide, and grow up to 30 inches long. The leaf blades have rough margins and a prominent midrib.The ligule is a fringe of hairs with a dense patch of hairs extending on the upper leaf surface.

Identifying Characteristics

Switchgrass can often be confused with bluestem and indiangrass. The flowers in large open panicles is distinctive characteristic. The hair at the point where the leaf attaches to the stem is a distinguishing characteristic compared to other warm-season grasses. The rhizomes are scaly and creeping.

Flower Seed Head

The seedhead is an open panicle that is 15 to 20 inches long and is usually formed in late may through June. The seed head is pyramid shaped.

Seed Fruit

Seeds are initially pink or dull purple but turn golden brown in the fall.

Where Found

Switchgrass is adapted for a wide range of soil types and site conditions. The growth habit enables it to survive extreme drought conditions. It is often grown as forage crop, natural wide life habitat, and as a bioenergy crop. Switchgrass spans throughout much of the U.S.

Leaf Hair on Upper Surface

no hairs

Leaf Arrangement

rolled in bud

Mature Leaf Width

more than 15 mm

Stem

round

Seedhead

panicle

Life Cycle

perennial

Auricle

not present

Ligule

hairy

Ligule Length

more than 3 mm

Plant Type

Grass