Weed Description: A
spreading summer annual that commonly is found growing along the ground but with tips
ascending (decumbent growth habit). Broadleaf signalgrass may reach as much as 3 feet in
height and is found most commonly as a weed of agronomic crops of the southeastern United
Seedling: Leaf sheaths are
often maroon-tinged and hairy throughout. Leaf blades are without hairs,
except for those that occur on the margins. Leaf blades may also be maroon-tinged,
with a fringed membranous ligule.
Stems: Prostrate, branching and
bent at the nodes, to approximately 3 ft tall. These plants often root at the lower
stem nodes, and therefore are most commonly seen growing along the ground with some tips
Leaves: Leaf blades are overall
short and wide in appearance, approximately 1 1/2 to 6 inches long and 6-15 mm wide. Leaf
blades are widest near the base and taper to the apex. Leaves are rolled in the bud
and without hairs on either leaf surface except on margins and in the collar region.
The ligule is a narrow membrane fringed with hairs, 1/2 to 1 mm long. Leaf
sheaths are hairy.
Roots: Roots are fibrous and
capable of rooting at the lower stem nodes.
Flowers: Seedhead a raceme,
approximately 12 inches long and 4 inches wide. Each seedhead has 2 to 6 'branches',
approximately 1 to 3 1/2 inches long. Spikelets on the seedhead are somewhat
flattened in appearance.
Identifying Characteristics: The relatively broad and short leaves of this grass weed make it easily
distinguishable from other grasses. Additionally, the lack of hairs on the leaf
blades, rooting stem nodes, and flattened spikelets help to identify broadleaf signalgrass
from most other grasses found in similar environments. Broadleaf signalgrass is
similar to Texas panicum (Panicum texanum)
in growth habit and appearance. However, the leaves of broadleaf signalgrass are not
covered with short, soft hairs like those of Texas panicum.