Weeds Identification Gallery

Fall Panicum

  • Panicum dichotomiflorum
  • Grass Family: Poaceae
Updated: 12/2025

Fall panicum is an annual grass. In California it is found in the San Joaquin Valley and southwestern region to about 1600 feet (500 m). It grows in fields, unmanaged, disturbed places, and prefers areas with moist soils such as along streams, tailwater ponds, and irrigation ditches. Witchgrass, Panicum capillare, a related species, is similar in appearance to fall panicum, but is much more widespread.

Grass seedling with the light shining on it so the leaf hairs are easily seen. Copyright information is at the bottom (Copyright 2007 The Regents of the University of California. All rights reserved.). Credit: Richard H. Uva
Hairs on seedling. Credit: Richard H. Uva

Mature Plant

Plants grow upright or spread from a bent or twisted base up to about 3-1/3 feet (1 m). Leaves often have a prominent wide midrib. Unlike witchgrass, fall panicum has hairless or nearly hairless leaf blades.

Mature plant showing short, stubby stems, smooth, slender leaves and flower heads (panicles); . Credit: Jack Kelly Clark, UC IPM
Mature plant. Credit: Jack Kelly Clark, UC IPM

Collar Region

The ligule consists of a dense ring of white hairs. There is no auricle.

Middle of grass stem showing ligule with dense ring of white hairs. Copyright information is at the bottom (Copyright 2007 The Regents of the University of California. All rights reserved.). Credit: Joseph M. DiTomaso, UC Agriculture and Natural Resources
Collar and sheath. Credit: Joseph M. DiTomaso, UC Agriculture and Natural Resources

Flowers

Spikelets grow in open branches that together form a pyramid or triangle shape. Unlike witchgrass, fall panicum spikelet stalks are tiny and lay close to the flowering branches.

Flower head with one leaf blade and five branches. Copyright information is at the bottom (Copyright 2007 The Regents of the University of California. All rights reserved.). Credit: Joseph M. DiTomaso, UC Agriculture and Natural Resources
Flower head. Credit: Joseph M. DiTomaso, UC Agriculture and Natural Resources
Seventeen 1.5 mm spikelets and florets. Half are smooth and shiny, while the others are covered in a paper-like wrapper that is pointed on one end. Copyright information is at the bottom (Copyright 2007 The Regents of the University of California. All rights reserved.). Credit: Jack Kelly Clark, UC IPM
Spikelets and florets. Credit: Jack Kelly Clark, UC IPM

Reproduction

Reproduces by seed.

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