Buffalo Quick Paspalum

Paspalum paspalodes closely resembles the more tropical Paspalum vaginatum Sw. The latter can be recognised by its narrowly ovate-elliptic spikelets, the papery upper glume and lower lemma, and the glabrous upper glume.

The type sheet of Paspalum distichum Linn. bears pieces of two different species. One is Paspalum paspalodes, to which the name “Paspalum distichum” has universally been applied; and Paspalum vaginatum, beside which the faded inscription “Br” indicates that this was the plant collected by Browne. In Sp. Pl., ed. 2, 1:82. 1762, Linnaeus gave the locality of Paspalum distichum as Jamaica, and as Browne collected in Jamaica it appears that the specimen known as Paspalum vaginatum is in fact the true type of Paspalum distichum. The fading of the inscription and the later addition of other material to this sheet are the source of the present nomenclatural confusion. Our species can no longer be called Paspalum distichum, but whether Paspalum vaginatum should be renamed Paspalum distichum is questionable. Clayton (Fl. Trop. E. Afr., Gram. part 3, in press) maintains that to start switching the names of two very similar species at this late stage will cause endless unnecessary confusion. This is a valid point of view resulting in Paspalum distichum Linn. being abandoned altogether as a nomen confusum.

Paspalum paspalodes provides good pasturage, especially on alluvial flats. Known as Knotgrass (in North America) it occurs as a garden weed, along ditches and irrigation channels, as a weed in rice-fields, and is gregarious in swampy places.

The length of the lower glume is very variable, even within a single raceme. The spikelets are not obviously hairy because the pubescent upper glume faces inward, but the creeping habit together with paired racemes of plump spikelets are distinctive. Rarely the upper glume is glabrous, but such specimens can be separated from the closely related Paspalum vaginatum by spikelet shape and by the longer, apiculate fertile floret.

Perennial with rhizomes and stolons. Culms 20–50 cm tall, nodes usually pubescent. Leaf sheaths keeled, glabrous, margins ciliate; leaf blades linear, 5–10 × 0.3–0.7 cm, glabrous, apex acute; ligule 2–3 mm. Inflorescence of 2(–3) racemes arising together or separated by a short axis; racemes 3–7 cm; spikelets single, in 2 rows; rachis straplike, 1.5–2 mm wide. Spikelets pallid, obovate-oblong, plano-convex, 3–3.5 mm, acute; lower glume vestigial or a narrow triangular scale up to 1/2 spikelet length or more; upper glume papery, 3–5-veined with distinct middle vein, loosely appressed pubescent; lower lemma 3–5-veined, usually glabrous; upper lemma pale green, almost equal to spikelet, cartilaginous, apex apiculate and minutely pubescent. Fl. and fr. May–Sep. 2n = 40, 48, 60.

Perennials; stolon creeping, stout, flowering culm very short, 20-50 cm tall, nodes thickened and pubescent. Blade 5-10 cm long, 3-7 mm wide, glabrous; sheath glabrous, margins ciliate; ligule membranaceous, truncate and fringed, 2-3 mm long, glabrous abaxially; Racemes 2, 2-6 cm long; rachis 1.5- 2 mm wide, flat. Spikelets solitary, obovate-oblong, acute, loosely pubesent, ca. 3 mm long; lower glume usually absent, developed in a few spikelets, triangular in shape, ca. 0.3 mm long; upper glume appressed pubescent; lower lemma 3-5-veined, usually glabrous, acute; upper lemma nearly as long as spikelet, coriaceous, pale green, acute, hairy at apex.

Creeping stoloniferous perennial; culms 6-50 cm high. Leaf-blades 5-20 cm long, 2.5.6.5 mm wide. Inflorescence composed of 2(4) conjugate racemes, each raceme 1.5-7 cm long, the spikelets single in 2 rows on a flattened rhachis 1-2 mm wide. Spikelets ovate, 2.5-3.5 mm long, plano-convex, relatively plump, pale-green; lower glume often present as a small scale; upper glume appressed-puberulent, herbaceous, with a distinct mid-vein; lower lemma similar but glabrous: upper lemma smooth, pallid at maturity.

The tropics and subtropics of the world. Taiwan, in roadsides, dampy places and along ditches.

Tropics & subtropics of Old World.

Distribution: Pakistan (Sind, Punjab, N.W.F.P. & Kashmir); tropics and sub-tropics throughout the world.

200-2000 m

Fl. & Fr. Per.: April-May and again August-September.

Fields, roadsides, ditches and other disturbed places, mostly on moist fertile soils. Anhui, Fujian, Guangxi, Guizhou, Hainan, Henan, Hong Kong, Hubei, Hunan, Jiangsu, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [tropical and warm-temperate regions of the world].

Digitaria paspalodes Michaux; Paspalum paspalodes (Michaux) Scribner.

More info for the term: cover

Prescribed fires were conducted annually in northern Florida on sites
where Paspalum species were present in the understory. Some plots were
burned annually, some every second winter, some every third, some every
fourth, etc. through 12 winters. Annual and biennial burning maintained
the highest grass covers; cover declined sharply starting with fires
every third year [21].

knotgrass
seashore paspalum
salt jointgrass
turfgrass

More info for the term: graminoid

Knotgrass is a native, perennial, rhizomatous graminoid [9]. Its culms
are 7 to 20 inches (0.2-0.6 m) high and are sometimes pubescent [17,18].
Usually two racemes are found at the end of the stem. Leaf blades are
flat and from 2 to 6 inches (5-15 cm) long. Rhizomes form dense,
extensive mats [5].

Knotgrass is common throughout the southeastern states; it occurs as far
north as Massachusetts and south into Mexico and South America. It is
also narrowly distributed throughout the Southwest and continues north
through California to coastal Oregon and Washington, and central Idaho
[9].

More info for the term: fire regime

Rhizomes generally enable knotgrass to survive fire.

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

More info for the term: litter

Fire can be used to reduce litter and increase plant vigor and
production in grasses. Fire can also be used to maintain open
grasslands by preventing establishment of woody vegetation [21].

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More info for the terms: geophyte, phanerophyte

Phanerophyte
Geophyte

More info for the terms: fresh, vine

Knotgrass is found along fresh and brackish marshes, coastal salt
marshes, ponds, ditches, shorelines, beaches, and dunes; and in
freshwater wetlands of the semiarid grasslands of the Southwest
[4,8,11,18]. Some associates include sea purslane (Sesuvium
portulacastrum), beach dropseed (Sporobolus virginicus), Mexican beach
peanut (Okenia hypogaea), railroad vine (Ipomoea pes-caprae), sea
lavender (Argusia gnaphalodes), beachberry (Scaevola plumieri), bay
cedar (Suriana maritima), cordgrass (Spartina spp.), muhly grass
(Muhlenbergia spp.), sedge (Carex spp.), horsetail (Equisetum spp.),
spikerush (Eleocharis spp.), rush (Juncus spp.), Olney bulrush (Scirpus
olneyi), slender wheatgrass (Elymus trachycaulus ssp. trachycaulus), and
johnsongrass (Sorghum halpense) [3,4,11,14].

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES41 Wet grasslands
FRES42 Annual grasslands

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

K049 Tule marshes
K072 Sea oats prairie
K088 Fayette prairie

Fire probably topkills knotgrass.

Knotgrass is a valuable duck food in the marshes of Louisiana [3]. It
is also considered a good forage grass in Arizona [12].

More info for the term: graminoid

Graminoid

Knotgrass increases in response to grazing [3]. It is useful as a soil
binder along streams but can sometimes be troublesome, as it chokes out
irrigation ditches [8,12,17].

AL AZ AR CA DE FL GA ID HI LA
MD MA MS NV NJ NM NC OK OR SC
TN TX UT VA WA MEXICO

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More info for the term: fruit

Knotgrass flowers and produces fruit between June and November [15,18].

Knotgrass sprouts from rhizomes following fire [21].

More info for the terms: herb, rhizome

Rhizomatous herb, rhizome in soil

Regeneration occurs mostly from the spreading and sprouting of rhizomes.
Creeping stems root at the nodes and give rise to flowering stems [8].

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
7 Lower Basin and Range
14 Great Plains

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More info for the term: vine

Knotgrass replaces marshbay cordgrass (Spartina patens) and Olney
bulrush in Gulf Coast marshes where grazing has reduced these species.
Knotgrass is then replaced by "annuals and unpalatable forbs" [1].
Along the southern Florida coast south of Cape Canaveral, knotgrass
along with pink-flowered railroad vine may recolonize the upper beach
from the foredune after storm erosion [11].

Paspalum vaginatum Sw.
Paspalum paspalodes (Michx.) Scribn.

The currrently accepted scientific name for knotgrass is Paspalum
distichum L. (Gramineae) [9]. Although many authorities distinguish the
closely related species P. vaginatum, Godfrey and Wooten [11] consider
this distinction unwarranted. Paspalum vaginatum and P. distichum will
be treated as a single species for the purpose of this report.

More info for the term: scarification

Knotgrass is sometimes used to revegetate eroded marshes in Louisiana
[14]. It is also used to rehabilitate overgrazed ranges in Arizona.
Results of this project have not yet been released [22]. In germination
tests, seeds were incubated at 82 to 95 degrees Fahrenheit (28-35 deg
C). Fourteen percent germinated in the dark, while 40 percent
germinated with 16 hours of light. Ripening can be sped up with dry
storage at 122 degrees Fahrenheit (50 deg C). Scarification with acid
can increase germination [10].

distichum: distichous

Paspalum distichum L. Syst. Nat. ed. 10. 855. 1759
Digitaria paspalodes Michx. Fl. Bor. Am. 1 : 46. 1803.
Paspalum. Digitaria Poir. in I,am. Encyc. Suppl. 4 : 316. 1816.
Paspalum Michauxianum. Kunth, Rev. Gram. 25. 1829.
Panicum pofyrhizum J. Presl, in Presl, Rel. Haenk. 1 : 296. 1830.

Paspalum oaxacense Steud. Syn. Gram. 21. 1854 Dimorphostachys Schaffneri Fourn. Mex. PI. Gram. 15. 1881. Dintorphosiachys Schaffneri remohspicula Fourn. Mex. PI. Gram. 15. 1881. Dimorphostachys variabilis Fourn. Mex. PL Gram. 15. 1881. J Dimorphostachys Ghiesbreghtii Fourn. Mex. PI. Gram. 16. 1881.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stolons or runners present, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems mat or turf forming, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stem internod es hollow, Stems with inflorescence less than 1 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 and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades more or less hairy, 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 a panicle with narrowly racemose or spicate branches, Inflorescence with 2-10 branches, Inflorescence branches 1-sided, Inflorescence branches paired or digitate at a single node, Inflorescence branches paired racemes, V-shaped, Rachis dilated, flat, central axis to whi ch spikelets are attached, Rachis winged, Rachis angular, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, 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 solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets conspicuously hairy , 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 2 clearly present, 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 acute or acuminate, Lemma awnless, Lemma straight, Palea present, well developed, Palea shorter t han lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Paspalum distichum is a species of grass. Common names include knotgrass, water finger-grass, couch paspalum, eternity grass, gingergrass, and Thompson grass. Its native range is obscure because it has long been present on most continents, and in most areas it is certainly an introduced species. Its native range probably includes parts of the tropical Americas.

This is a perennial grass forming clumps and spreading via rhizomes and stolons. It grows decumbent or erect to a maximum height near 60 centimeters. The inflorescence is usually divided into two branches lined with spikelets.

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