Paspalum dilatatum , or Dallis grass, is a common perennial weed often found in lawns and disturbed areas. It is an invasive bunchgrass and its dense growth habit tends to smother and prevent other native species from flourishing. Its rapid growth and profuse seed production enable it to quickly invade agricultural land, especially rice fields, waterway margins, and managed urban sites. However, it is sometimes used as a summer forage grass in pastures. If it is to be used in pastures, try to maintain a height of 2 to 3" because a lower grass height can result in a decline of the grass. Dallis grass spreads from a short rhizome and has thick and deep fibrous roots. The leaf stalks are hollow and form a coarse, spreading tuft, while the leaves themselves are blade-shaped and grow up to 10 inches long. The lower sheaths of the leaves are somewhat hairy, but the leaf blades are hairless. There are typically 3 to 7 groups of flowers (racemes) on a stem, each less than 2 inches long, forming at nearly right angles to the stem. The flower is small, fleshy, inversely coned shaped and 3-lobed. It forms at the opening of the flower bud. A major component of Dallis grass management is preventing the establishment of new plants. In home landscapes, digging out young plants before they form rhizomes or set seed is the best strategy for control. Mature plants can also be dug out, but they sometimes grow back if rhizomes are left behind. Insects, Diseases and Other Plant Problems: Seed heads are susceptible to an ergot fungus, Calviceps paspali , that is toxic to livestock when ingested. This is a weedy plant and is listed as invasive in SC and KY. This species is classified as invasive by the NC Invasive Plant Council.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Dappled Sunlight (Shade through upper canopy all day) | Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Loam (Silt); Sand
Soil drainage
Occasional Flooding | Occasionally Wet
NC region
Coastal; Mountains; Piedmont
Growth rate
Medium
Maintenance
High
Canopy layer
4 - Herbaceous
Form & Appearance
Habit / form
Clumping; Dense; Erect
Texture
Coarse
Leaf color
Green; Red/Burgundy
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Linear
Leaf feel
Smooth
Leaf size
> 6 inches long, < 1 inch wide
Hairs present
Yes
Leaf detail
The leaf sheath is somewhat flattened and its base is hairy, often tinged red, and usually inflated. The leaf blades are fairly wide (1/4 go 1/2 inch). If left unmowed, blades will grow 4 to 10 inches long. At the base of each leaf blade is a collar with a membranous ligule about 1/4 inch long and no auricles or projections. At the base of the collar is the leaf sheath, which is slightly flattened. Frequently there is purplish coloration at the base of the grass stems.
Flower color
Gold/Yellow
Flower form
Insignificant; Raceme; Spike
Flower size
< 1 inch
Flower detail
The flowers are a paired spikelet. Dallis grass blooms from May through November. The flowering stalk grows 14 to 65 inches tall and the flower head consists of 2 to 10, often drooping, spikelets that arise from different points at the top of the flower stalk. Each spikelet has two rows of flat, egg-shaped seeds along its entire length and is pale green to purplish in color.
Bloom time
Fall; Summer
Fruit color
Brown/Copper
Fruit type
Achene
Fruit detail
Dallis grass produces abundant amounts of seed, which are its primary means of dispersal.
Stem color
Green; Purple/Lavender
Stem detail
The underground stems are fairly short and have areas that appear as concentric rings.
Wildlife & Ecology
Native status
Unknown
Origin
South East and Southern Brazil, South America
Distribution
AL, AR, AZ, CA, CO, FL, GA, HI, IL, KY, LA, MD, MO, MS, NC, NM, OK, OR, PR, SC, TN, TX, VA, WV