Dallisgrass

This native of South America is now widely distributed throughout the tropics as a forage grass and also occurs as a weed of cultivation.

Paspalum dilatatum, variously known as Golden Crown Grass, Dallis Grass or Caterpillar Grass, is a valuable forage grass introduced from South America and now established in Pakistan.

Paspalum urvillei Steud. is another introduced South American weed, which is established in Sri Lanka. Like Paspalum dilatatum it has ciliate spikelets, but there are 2-3mm long and borne on 10-18 racemes.

Perennials; culm tufted, glabrous, stout, mostly 50-150 cm tall; rhizome short. Blade glabrous; ligule 2-4 mm long, truncate, membranaceous, glabrous. Racemes usually 5-10, 6-8 cm long, axils of racemes pilose. Spikelets ovate-pointed, 3-3.5 mm long, green or purplish, in pairs, one subsessile and other shortly pedicelate; lower glume absent; upper glume and lower lemma membranaceous, 5-9- veined, margins fringed with long silky hairs, sparsely covered with silky hairs all over; upper lemma orbicular, ca. 2 mm long, rounded, coriaceous; anther ca. 1 mm long.

Perennial from a short rhizome. Culms forming a coarse, spreading tuft, 50–150 cm tall, ca. 5 mm in diam., glabrous. Leaf sheaths glabrous or pilose in the lower part; leaf blades linear, 10–45 × 0.3–1.2 cm, glabrous, apex attenuate; ligule 2–4 mm. Inflorescence axis 2–20 cm; racemes 2–10, 5–12 cm, spaced, diverging, axils pilose; spikelets paired; rachis 1–1.5 mm wide, glabrous. Spikelets green or purplish, broadly ovate, 3–4 mm, sharply acute; upper glume membranous, 5–9-veined, sparsely pubescent to almost glabrous on back, margins fringed with long white hairs; lower lemma similar but not hairy; upper lemma pallid at maturity, orbicular, ca. 2 mm, clearly shorter than spikelet, papillose-striate, apex rounded. Fl. and fr. May–Jul. 2n = 40, 50–63.

Tufted perennial; culms robust, 40-180 cm high. Leaf-blades lineal, 6-45 cm long, 3-12 mm wide. Inflorescence composed of (2-)3-5(-11) racemes borne along a common axis 2-20 cm long, each raceme 4-11 cm long, the spikelets paired in 2-4 rows on a rhachis ± 1.2 mm wide. Spikelets ovate, 2.8-3.8 mm long, yellowish green; upper glume as long as the spikelet, sparsely pilose on the surface, ciliate on the margins; lower lemma similar, but not ciliate; upper lemma papillose-striate, pallid at maturity.

Orinally from South America, naturalized elsewhere. Taiwan, common on waste grounds in northern Taiwan.

Distribution: Pakistan (Sind, Baluchistan; introduced); South America, now established in most tropical countries.

Fl. & Fr. Per. August-October.

Roadsides, waste places, naturalized. Fujian, Guangxi, Guizhou, Hong Kong, Hubei, Shanghai, Taiwan, Yunnan, Zhejiang [native to South America].

Digitaria dilatata (Poiret) H. J. Coste.

Paspalum dilatatum Poir. in I^am. Encyc. 5 : 35. 1804
Paspalum platense Spreng. Syst. 1 : 247. 1825.
Paspalum ovatum Nees ; Trin. Gram. Pan. 113. 1826.
Paspalum eriophorum Schultes, in R. & S. Syst. Veg. Mant. 3 : 560. 1827.
Paspalum lanatum Spreng. Syst. 4 : Cur. Post. 30. 1827. Not P, lanatum H.B.K. 1815.
Paspalum dilatatum decumbens Vasey, Bull. Torrey Club 13 ; 166. 1886.
A smooth and glabrous perennial, with flat leaf-blades and acute ciliate spikelets. Stems 5-17 dm. tall, somewhat compressed; leaf-sheaths compressed, glabrous; blades 3 dm. long or less, 3-12 mm. wide; racemes 3-8, 5-10 cm. long, erect or ascending, the rachis 1.2-1.5 mm. wide, straight; spikelets in pairs, so densely crowded that they appear as if in four rows, 3-3.5 mm. long, 2-2.2 mm. wide, nearly orbicular, acute, the first scale wanting, the second and third scales 5-7-nerved, the second scale ciliate with very long lax hairs, the third sparingly ciliate with much shorter hairs, the fruiting scale orbicular, white at maturity.
Type locality : Buenos Aires, Argentina.
Distribution : Virginia and Tennessee to Florida and Central America ; also in South America.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome short and compact, stems close, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy, hispid or prickly, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence lax, widely spreading, branches drooping, pendulous, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence with 2-10 branches, Inflorescence branches 1-sided, Rachis dilated, flat, central axis to which spikelets are attached, Rachis angular, Flowers bisexual, Spikelets pedicellate, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelet with 1 fertile floret and 1-2 sterile florets, Spikelets paired at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets di sarticulating below the glumes, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 1 clearly present, the other greatly reduced or absent, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes 3 nerved, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma straight, Palea present, well developed, Palea shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis white.

Paspalum dilatatum is a species of grass known by the common name dallisgrass, Dallas grass, or sticky heads. It is native to Brazil and Argentina, but it is known throughout the world as an introduced species and at times a common weed. Its rapid growth and spreading rhizomes make it an invasive pest in some areas. It is present in the southern half of North America, southern Europe, much of Africa, Australia, New Zealand, and many tropical and subtropical areas.

Paspalum dilatatum is a food source for several avian species, including the long-tailed widowbird.

The common name dallisgrass was derived from A. T. Dallis, a 19th-century farmer who grew the species extensively near La Grange, Georgia.