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Paspalum dilatatum

Phonetic Spelling
PASS-pal-lum dy-luh-TAY-tum
This plant is an invasive species in North Carolina
Description

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 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 and invasive plant.  

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#invasive#weed#weedy#grass#herbaceous#herbaceous perennial#disturbed areas#lawn weed
 
Cultivars / Varieties:
Tags:
#invasive#weed#weedy#grass#herbaceous#herbaceous perennial#disturbed areas#lawn weed
  • Attributes:
    Genus:
    Paspalum
    Species:
    dilatatum
    Family:
    Poaceae
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    South East and Southern Brazil, South America
    Distribution:
    Throughout southern and south central United States, California, and Oregon.
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    Food source for some birds.
  • Whole Plant Traits:
    Plant Type:
    Perennial
    Weed
    Habit/Form:
    Clumping
    Dense
    Erect
    Growth Rate:
    Medium
    Maintenance:
    High
    Texture:
    Coarse
  • Cultural Conditions:
    Light:
    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
    USDA Plant Hardiness Zone:
    6b, 6a, 7b, 7a, 8b, 8a, 9b, 9a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Fruit Type:
    Achene
    Fruit Description:
    Dallis grass produces abundant amounts of seed, which are its primary means of dispersal.
  • Flowers:
    Flower Color:
    Gold/Yellow
    Flower Inflorescence:
    Insignificant
    Raceme
    Spike
    Flower Bloom Time:
    Fall
    Summer
    Flower Size:
    < 1 inch
    Flower Description:
    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.
  • Leaves:
    Leaf Color:
    Green
    Red/Burgundy
    Leaf Feel:
    Smooth
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Linear
    Hairs Present:
    Yes
    Leaf Length:
    > 6 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    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.
  • Stem:
    Stem Color:
    Green
    Purple/Lavender
    Stem Is Aromatic:
    No
    Stem Form:
    Straight
    Stem Description:
    The underground stems are fairly short and have areas that appear as concentric rings.
  • Landscape:
    Problems:
    Invasive Species
    Weedy