Dallisgrass

Dallisgrass

Weed Flora of Mississippi

Family: Poaceae

Genus: Paspalum         Species:   dilatatum

History: Native to Brazil and Argentina, but it is known throughout the world as an introduced species. It is present in the southern half of North America, southern Europe, much of Africa, Australia, New Zealand, and many tropical and subtropical areas. It was introduced into the United States from South America in the 1800s for use as a forage plant.

Life Cycle: It is a warm-season perennial bunchgrass.

Special Characteristics: The common name dallisgrass was derived from A. T. Dallis, a 19th-century farmer who grew the species extensively near La Grange, Georgia. It is a food source for several avian species, including the long-tailed widowbird. It grows in a clump that slowly increases in diameter as its shallow, short, underground stems (rhizomes) grow outward. It tolerates both sandy and heavy clay soil and, once established, is drought-resistant and frost-tolerant.

Roots: Deep fibrous roots and short rhizomes.

Stems: Sheaths are compressed and mostly lack hair. Sheaths are often tinted red with age. Plants can tolerate mowing but may also grow to a height of 5 feet.

Leaves: The leaves are mostly hairless (with hairs near the collar only), growing up to 35 cm (14 in) long and 2.5 cm (1 in) wide. At the base of each leaf blade is a collar with a membranous ligule. The lower sheaths of the leaves are somewhat hairy, but the leaf blades are hairless.

Flower: The inflorescence is divided into a few branches lined neatly with beadlike pairs of green to purple spikelets. The flowering stalk is pale green to purple in color. Dallisgrass produces abundant seed, which are its primary means of dispersal. There are typically 3 to 7 groups of flowers (racemes) on a stem.

Seeds / Fruit: Seeds usually germinate in spring and summer when soil temperatures reach 60 to 65° F and the seedlings grow to form new clumps.

Interference:

Dallisgrass is a weed in turfgrass, wet roadside areas, irrigation ditch banks, orchards, vineyards, and ornamental landscaped areas. It is closely related and similar in appearance to knotgrass. (Paspalum distichum). It creates unsightly and uneven clumps in turfgrass, causing problems in golf courses, sports playing fields, recreational parks, and home landscapes where a uniform texture and surface is necessary.