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Weed Identification

dallis grass



Scientific Name

Paspalum dilatatum

Other Common Names:

water grass


Dallisgrass is a clumping perennial grass that spread from short thick rhizomes. Plants emerge in spring and early summer and bloom from midsummer to early autumn.


At seedling stage the first few leaves may have short soft hairs; however, after that point, there are only long hairs present on the plant located at the collar region and hairs along the leaf margin. Leaves are 0.25 to 0.50 inches wide and 4 to 10 inches long. It is pretty normal for the base of the grass stems to be purple. Mature plant has smooth sheaths and a tall membranous ligule (5mm). The leaf also has a prominent mid vein.

Identifying Characteristics

Dallisgrass has very strong prostrate tillers that do not root at the nodes. It also has short, shallow running rhizomes. The mid-rib helps distinguish between weeds like crabgrass and foxtail.

Flower Seed Head

Dallisgrass has a very distinct seedhead and is easily identifiable. Seed head is raceme, and has hairy spikelets. Flowers are produced on a tall terminal stalk that has 3-5 or more branches (2-3 inches in length) along the terminal end. The spikelets are ovate, wide, and covered in soft hairs. There are four rows of them, one each raceme.

Seed Fruit

The seeds are ovate, shiny and yellow to brown in color. Black anthers often persist as fruit mature giving the seedheads a characteristic look.

Where Found

This is a major turf weed, but also invades flower beds, pastures, and road-sides. While it can grow in many habitats it prefers moist conditions.

Leaf Hair on Upper Surface

no hairs

Mature Leaf Width

6 to 15 mm


flat or oval


multiple spikes

Root Structure


Life Cycle



not present



Ligule Length

more than 3 mm

Plant Type