Fall Panicum

Grass (Poaceae family):

Panicum dichotomiflorum Michx.

EPPO code:

PANDI

Other names:

Smooth panicum, smooth witch grass, spreading panic grass

Species information

Lifecycle:

Annual.

Propagation:

Reproduces by seed.

Emergence:

Fall panicum is one of the last annual grass species to emerge in the spring.

Habitat:

It is most commonly found in southwestern Ontario.

Competitiveness:

Agriculture and Agri-Food Canada research has shown that fall panicum densities of 20,000 plants/ac can result in a 10% yield loss in corn and soybeans.

Identification clues

Auricles:

None.

Ligule:

Hairy.

Leaf blade:

Very young seedlings can be densely hairy, but will become less hairy with age. Older seedling plants feel smooth and hairless, but do contain a very prominent midrib.

Leaf sheath:

The margins of the sheath are hairless.

Stem:

Round.

Seed heads:

Seed heads appear as several branches of panicles that contain seed that is yellow to brown in colour.

Roots:

Fibrous.

Often mistaken for

I know it's not Green foxtail because fall panicum does not have hairy leaf sheath margins.

I know it's not Giant foxtail because the upper leaf blade of fall panicum is hairless and it does not have hairy leaf sheath margins.

I know it's not Proso millet because fall panicum does not have hairy stems or hairs along the base of the leaf blade’s margin

I know it's not Witchgrass because fall panicum isn’t as hairy as witchgrass, which is extremely hairy. Also, the leaf blade of witchgrass lacks the prominent midrib that fall panicum has.