Paspalum vaginatum Sw., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 7 (Go to the risk assessment)

Other Latin names:  Palspalum distichum sensu auct. non L.

Common name(s): [more details]

Chinese: hai que bai

English: biscuit grass, knot grass, knottweed, salt grass, saltwater couch, saltwater paspalum, seashore grass, seashore paspalum, silt grass, swamp couch

Fijian: kambutu

French: herbe rampante

I-Kiribati: te utiuti

Mangarevan: motie, mutie

Maori (Cook Islands): mauku ta‘atai, mauku vairākau

Marquesan: matie, mutie

Marshallese: katejukjuk, wûjooj

Niuean: mosie kalalahi

Pohnpeian: dimur, dumwur, timoor

Samoan: mutia

Spanish: gramón, grama de costa, grama de mar, gramilla, gramilla blanca

Tongan: mohuku ano

Habit:  grass

Description:  "Extensively creeping perennials, stoloniferous, often forming extensive colonies, the stolons slender and wiry to stout and slightly fleshy; culms slightly compressed, 2.5-5 (-10) dm long, glabrous, the flowering ones usually shorter, usually grooved, ± branching, sterile culms with short, broad, loose, often overlapping sheaths, and conspicuously distichous, stiffly ascending blades, or bladeless.  Sheaths often keeled, with small auricles; ligule membranous, ca. 0.5 mm long, with a ring of soft white hairs behind it, the hairs sometimes up to 5 mm long; blades usually stiff, ascending at an uniform angle, 2.5-15 cm long, 3-8 mm wide at base, narrower than summit of sheath, apex attenuate, involute, base abruptly contracted.  Racemes 2 (-5), opposite or closely approximate, at first erect and appressed together, usually spreading or reflexed at maturity, often subfalcate, 1.5-7.5 cm long, rachis naked at base, 1-2 (-2.5) mm wide, triangular, flexuous, margins minutely scabrous; spikelets pale, solitary, imbricate, oblong, 3-4.5 mm long, 1.2-1.5 mm wide; first glume rarely developed, second glume and first lemma equal, thin, 3-7-nerved, the midnerve of both usually obscure, glabrous; first lemma usually transversely undulate, sometimes conspicuously so; second lemma convex, usually 3-5-nerved, apex with a few short, stiff cilia, otherwise glabrous; palea flat, 0-2-nerved, similar to lemma.  Caryopsis narrowly obovate, slightly concavo-convex, 2.5-3 mm long, subacute"  (Wagner et al., 1999; pp. 1577-1578).

Description of Paspalum vaginatum from Kew Garden's GrassBase.

See also Paspalum distichum L. for records of this closely related species.  Many occurrences throughout the Pacific region may be misidentified as Paspalum distichum.

Habitat/ecology:  "Salt grass is pantropical in distribution, but is likely to have been an unintentional European introduction over most of its Pacific range.  In Micronesia it is found in nearly all the Micronesian archipelagoes, including the Marshall Islands (many atolls), where it appears to be a modern natural arrival.  [On Kwajalein} it is occasional to locally common in sunny coastal areas"  (Wagner & Steele, 1999; p. 88).  On Majuro, Marshall Islands, it is a "weedy plant forming dense patches near beaches and brackish marshy areas; often found in, or bordering, taro pits"  (Vander Velde, 2003; p. 52).  In Hawai‘i, "naturalized in coastal sites in shallow brackish water and on brackish sands, often forming pure stands at sea level"  (Wagner et al., 1999; p. 1578).  On Niue, "commonest on the more exposed south- and east-facing coasts"  (Sykes, 1970; p. 250).  On Guam, "usually near the sea or in brackish marshes, sometimes in mangrove regions"  (Stone, 1970: p. 217).  "In Fiji it is usually found near sea level...on beaches and creek banks and in mangrove swamps"  (Smith 1979; p. 336).

Propagation:  Seed

Native range:  "Native range unknown, now widely distributed in warm temperate to tropical sea coasts and brackish marshes worldwide" (Wagner et al., 1999; p. 1578).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
American Samoa Manu‘a Islands	Ta‘u Island		Yuncker, T. G. (1945) (p. 24) Vouchers cited: W. Harris 305 (BISH), A. Harris 73 (BISH)
American Samoa Tutuila Islands	Tutuila Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1992) (voucher ID: PTBG 16355) Taxon name on voucher: Paspalum vaginatum Sw.
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	possibly native	Orchard, Anthony E., ed. (1994) (p. 12) "Although possibly native, this species has not, as far as is known, been recorded from the Island for about a century". Voucher cited: 1898, J.H. Maiden (K, NSW)
Cook Islands Northern Cook Islands	Nassau Island	native	McCormack, Gerald (2013)
Cook Islands Southern Cook Islands	Aitutaki Atoll	native	McCormack, Gerald (2013)
Cook Islands Southern Cook Islands	Mangaia Island	native	McCormack, Gerald (2013)
Cook Islands Southern Cook Islands	Rarotonga Island	native	McCormack, Gerald (2013)
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	native	Charles Darwin Research Station (2005)
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	native	Charles Darwin Research Station (2005)
Federated States of Micronesia Kosrae Island	Kosrae Island	native	Lorence, David H./Flynn, Timothy (2010) (p. 10) Voucher cited: Lorence 9393 (PTBG)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	native	Herrera, Katherine/Lorence, David H./Flynn, Timothy/Balick, Michael J. (2010) (p. 60) Vouchers cited: A. Dores 97 (BISH, NY, PTBG), A. Dores 219 (NY, PTBG), B. Ekiek 78 (BISH, NY, PTBG), F.R. Fosberg 26125 (BISH), R. Gallen 74 (NY, PTBG), S.F. Glassman 2630 (BISH), S.F. Glassman 2649 (BISH), S.F. Glassman 2898 (BISH), E.Y. Hosaka 3466 (BISH), E.Y. Hosaka 3563 (BISH), T. Hosokawa 6127 (BISH), N.L.H. Krauss 1898a (BISH), S.H. Riesenberg 71 (BISH)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2006) (voucher ID: PTBG 49082) Taxon name on voucher: Paspalum vaginatum
French Polynesia Gambier Islands	Agakauitai Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Gambier Islands	Agakauitai Island	native	St. John, Harold (1988) (p. 8) Voucher cited: St. John 14948 (BISH)
French Polynesia Gambier Islands	Aukena Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Gambier Islands	Aukena Island	native	St. John, Harold (1988) (p. 8) Voucher cited: St. John 14636 (BISH)
French Polynesia Gambier Islands	Makaroa Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Gambier Islands	Makaroa Island	native	St. John, Harold (1988) (p. 8) Voucher cited: Quayle & Curtis 454 (BISH)
French Polynesia Gambier Islands	Mangareva (Gambier) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Gambier Islands	Mangareva (Gambier) Island	native	St. John, Harold (1988) (p. 8) Vouchers cited: St. John 14551 (BISH), Fosberg 11069 (BISH)
French Polynesia Marquesas Islands	Fatu Hiva Island	native	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Marquesas Islands	Fatu Hiva Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 7379 (PAP)
French Polynesia Marquesas Islands	Hiva Oa Island	native	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Marquesas Islands	Hiva Oa Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Marquesas Islands	Hiva Oa Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2004) (voucher ID: PTBG 42407) Taxon name on voucher: Paspalum vaginatum
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	native	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 8506 (PAP). As Paspalum distichum L.: Vouchers cited: J. Florence 4395 (PAP), s. nom coll. 4252 (PAP)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island	native	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2004) (voucher ID: PTBG 43299) Taxon name on voucher: Paspalum vaginatum
French Polynesia Marquesas Islands	Ua Pou (Huapu, Uapou, Uapu) Island	native	Lorence, David H./Wagner, Warren L. (2013)
French Polynesia Society Islands	Bora Bora Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 12057 (PAP)
French Polynesia Society Islands	Huahine Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Society Islands	Maupiti (Maurua) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Society Islands	Moorea Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) As Paspalum distichum L. Voucher cited: J. Florence 4610 (PAP)
French Polynesia Society Islands	Raiatea (Havai) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) As Paspalum distichum L. Voucher cited: J. Florence 3468 (PAP)
French Polynesia Society Islands	Taha‘a Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 10613 (PAP). As Paspalum distichum L.: Voucher cited: J. Florence 5258 (PAP)
French Polynesia Society Islands	Taha‘a Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1990) (voucher ID: PTBG 37018) Taxon name on voucher: Paspalum vaginatum Sw.
French Polynesia Society Islands	Tahiti Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence & J.-C. Jolinon 8084 (PAP)
French Polynesia Society Islands	Tupai Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Tuamotu Archipelago	Makatea (Ma‘atea) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 9026 (PAP)
French Polynesia Tuamotu Archipelago	Niau Atoll	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 10071 (PAP)
French Polynesia Tuamotu Archipelago	Rangiroa (Rairoa) Atoll	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) As Paspalum distichum L. Voucher cited: J. Florence 4071 (PAP)
French Polynesia Tuamotu Archipelago	Takapoto Atoll	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Tuamotu Archipelago	Tepoto Nord Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Austral (Tubuai) Islands	Raivavae (Raevavae) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) As Paspalum distichum L. Voucher cited: J. Florence 5771 (PAP)
French Polynesia Austral (Tubuai) Islands	Rapa Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Austral (Tubuai) Islands	Rimatara (Rimitara) Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Austral (Tubuai) Islands	Rurutu Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
French Polynesia Austral (Tubuai) Islands	Tubuai Island	native	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1578)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1578)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Herbarium Pacificum Staff (1999) (p. 8) West Maui. Voucher cited: C. Imada, K. Evans & M. Nishimoto 98-30
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Oppenheimer, Hank L. (2003) (p. 22) Voucher cited: Oppenheimer H110147 (BISH)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1578) Voucher cited: Fosberg 13182 (BISH)
Kiribati Tungaru (Gilbert) Islands	Butaritari Atoll		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1972) (voucher ID: PTBG 23095) Taxon name on voucher: Paspalum vaginatum Sw.
Kiribati Tungaru (Gilbert) Islands	Tarawa Atoll		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1972) (voucher ID: PTBG 23094) Taxon name on voucher: Paspalum vaginatum Sw.
Marshall Islands Ralik Chain	Kili (Kõle) Atoll	introduced invasive	Vander Velde, Nancy/Vander Velde, Brian (2006) (p. 4) "Abundant to very abundant; along roadsides and in fields, forming large patches often dominating low-lying vegetation of wetland areas".
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 54) As Palpalum distichum L.
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	introduced invasive	Whistler, W. A./Steele, O. (1999) (p. 88) Voucher cited: Fosberg 31189, Fosberg 31207, Fosberg 34123, Herbst 9051, Whistler 11162, Whistler 11196
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1998) (voucher ID: PTBG 43973) Taxon name on voucher: Paspalum vaginatum Sw.
Marshall Islands Ratak Chain	Arno Atoll	introduced invasive	Vander Velde, Nancy/Vander Velde, Brian (2007) (p. 3) "Uncommon to rare; patch near school in Ine observed from distance".
Marshall Islands Ratak Chain	Arno Atoll	introduced	Vander Velde, Nancy/Vander Velde, Brian (2009) (p. 4) Voucher cited: Vander Velde 0627200906
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 54) As Palpalum distichum L.
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll	introduced invasive	Vander Velde, Nancy (2003) (p. 52)
Marshall Islands Ratak Chain	Mili (Mile) Atoll	introduced invasive	Vander Velde, Nancy/Vander Velde, Brian (2010) (p. A7) Uncommon; small area in cistern of old school and few wetland areas of Mili. Voucher 0723201003 (BISH, GUAM, PTBG)
Marshall Islands Ratak Chain	Wotje (Wõjjã) Atoll	introduced	Vander Velde, Nancy/Vander Velde, Brian (2009) (p. 1) Voucher cited: Vander Velde 0513200905
Marshall Islands Ratak Chain	Wotje (Wõjjã) Atoll		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2009) (voucher ID: PTBG 49812) Taxon name on voucher: Paspalum vaginatum
Niue Niue	Niue Island	native	Sykes, W. R. (1970) (pp. 249-250) Vouchers cited: CHR 168741, CHR 168743
Palau Palau (Belau ) (main island group)	Palau Islands (main island group)		Lorence, David H./Flynn, Tim (2010) (p. 17)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Henty, E. E. (1969) (p. 146)
Philippines Philippine Islands	Philippine Islands		Waterhouse, D. F. (1993) (p. 67)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1925) (p. 57) In open wet lands, usually in places subject to the influence of salt or brackish water.
Philippines Philippine Islands	Philippine Islands		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 108)
Tonga Tongatapu Group	Tongatapu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1989) (voucher ID: PTBG 3863) Taxon name on voucher: Paspalum vaginatum Sw.
Tuvalu Tuvalu (Ellis) Islands	Tuvalu Islands		Swarbrick, John T. (1997) (p. 95)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Australia (continental)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 108)
China China	China (People's Republic of)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 108)
China China	Hong Kong	native	Wu, Te-lin (2001) (p. 343)
Indonesia Indonesia	Indonesia (Republic of)		Waterhouse, D. F. (1993) (p. 67)
Indonesia Indonesia	Indonesia (Republic of)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 108)
Malaysia Malaysia	Malaysia (country of)		Waterhouse, D. F. (1993) (p. 67)
Mexico Mexico	Mexico (United Mexican States)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 108)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Edgar, E./Connor, H. (2000) (p. 570) "Coastal, often brackish, areas; often forming swards near edge of mud flats, or on sandy and shingly shores and occasionally spreading into pasture nearby".
Singapore Singapore	Singapore (Republic of)	native	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 67) Common
South America (Pacific rim) South America (Pacific rim)	Chile (Republic of)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 108)
Taiwan Taiwan Island	Taiwan Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 269)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Waterhouse, D. F. (1993) (p. 67)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Indian Ocean offshore islands) Cocos (Keeling) Islands	Cocos (Keeling) Islands	native	Orchard, Anthony E., ed. (1993) (p. 39)
British Indian Ocean Territory Chagos Archipelago	Diego Garcia Island	introduced invasive	Whistler, W. Arthur (1996) (p. 25)
Maldives Maldive Islands	Malè Atoll		Fosberg, F. R. (1957) (p. 12) Voucher cited: Fosberg 36853 (US)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 269)

Control:  If you know of control methods for Paspalum vaginatum, please let us know.