Texas panicum
Family
PoaceaeScientific Name
Urochloa texanaOther Common Names:
Texas signalgrass
Synonyms (former Scientific Names):
Brachiaria texana
Panicum texanum
Habit
A spreading summer annual that may have an erect growth habit or grows close to the ground with tips ascending (decumbent growth habit). Texas panicum may reach as much as 32 inches tall and can root at the lower nodes.
Leaves
Leaf blades range from 3 to 11 inches in length and may reach as much as 4/5 inch in width. Leaves are covered with short, soft hairs on both surfaces. Auricles are not present and the ligule is membranous and fringed with hairs, from 1 to 1.8 mm long.
Identifying Characteristics
A summer annual with relatively wide leaves that are covered with soft minute hairs on both surfaces. Texas panicum is very similar in appearance and growth habit to Broadleaf Signalgrass (Brachiaria platyphylla). However, broadleaf signalgrass has hairs only along the leaf margins unlike Texas panicum. Additionally, the two can be distinguished in the seedling stage by the lack of hairs on the leaves of broadleaf signalgrass compared to the small velvety hairs on both leaf surfaces of Texas panicum. Texas panicum seedlings also very closely resemble Large Crabgrass (Digitaria sanguinalis) in appearance. Once ligules become noticeable, however, the two can be readily distinguished from one another. Large crabgrass has a relatively tall membranous ligule with jagged edges while Texas panicum has a ligule that is membranous at the base but fringed with hairs on the top.
Stems may be erect to as much as 32 inches in height or may grow close to the ground with tips ascending (decumbent growth habit). Stems may reach as much as 4 1/2 feet in length and plants can root at the lower nodes. Stem nodes are distinctive and are also covered in soft hairs.
Seedlings of this grass weed have leaf sheaths and blades that are covered with soft hairs on both surfaces. First leaves are relatively broad compared to most annual grasses. The fairly large seed from which seedlings arise also helps in the identification of this species.
Flower Seed Head
Seedhead a simple, narrow panicle that ranges from 2 3/4 to10 inches in length. Each 'spike' has 2 rows of spikelets that are each approximately 3 mm long.
Seed Fruit
Seeds are light brown in color and approximately 5mm in length.
Where Found
Texas panicum is found throughout the southeastern United States and has developed into a significant weed of agronomic crops.
Leaf Hair on Upper Surface
hairs from base to tip
Leaf Arrangement
rolled in bud
Mature Leaf Width
Varies:
6 to 15 mm,
more than 15 mm
Stem
flat or oval
Seedhead
panicle
Root Structure
fibrous
Life Cycle
summer annual
Auricle
not present
Ligule
Varies:
membrane,
hairy
Ligule Length
Varies:
less than 1 mm,
1-2 mm
Plant Type
Grass