Mucuna pruriens (L.) DC., Fabaceae

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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:  Dolichos pruriens L.; Stizolobium aterrimum Piper and Tracey; Stizolobium deeringianum Bort.; Stizolobium niveum Kuntze.; Stizolobium pruriens (L.) Medicus.

Common name(s): [more details]

Chamorro: akangkang dangkulo

Chinese: ci mao li dou

English: Bengal bean, cow itch, cowhage, itchweed, Mauritius bean, velvet bean

French: poil à gratter, pois pouilleux

Spanish: ojo de buey, ojo de venado

Habit:  vine

Description:  "Semiwoody twining vines. Stems and branchlets slender, with dense long fine hairs and often coarser longer hairs, later glabrous. Leaves up to 46 cm; petiole 8-26 cm, hairy like stem; stipels robust, tapering to tip, 4-5 mm; leaflets papery, adaxially sparsely or abundantly hairy when young, later glabrous, abaxially clothed with short white silky hairs, lateral veins 5-8 on each side, slender, straight or slightly curved, running into margin; terminal leaflet elliptic or ovate-rhombic, (3-) 14-16 x (4.5-) 8-10 cm, base broadly cuneate to rounded, apex rounded, acute, or shortly acuminate; lateral leaflets 7-19 cm, width ratio of abaxial to adaxial halves 2-3:1, abaxial half with base ± truncate or rarely cordate. Inflorescence axillary, long and pendulous, 15-35 cm, with (2-) 5-20 nodes, all in upper 2/3 of inflorescence with no bracts or scars in lower part; pedicels 2-4 (-6) mm, densely adpressed hairy and often bristly; bracts and bracteoles linear-lanceolate 6-9 mm, hairy, caducous before flowers open. Calyx with dense soft adpressed pale hairs and often irritant orange bristles; tube ca. 5 x 10 mm; lateral 2 lobes broadly triangular, 2-4 x 1.5-3 (-3.5) mm, lowest narrowly triangular, 6-10 x 2-3 mm. Corolla deep purple; standard 1.6-2.5 cm, 1/2-2/3 of keel length; wings 2-4 x ca. 1.2 cm, shorter than or subequal to keel; keel 2.8-4.2 (-4.5) cm. Legume linear-oblong and slightly swollen around seeds or misshapen with irregular swellings around seeds, to 9 x 1 (-2) cm, ca. 5 mm thick, densely covered with soft pale hairs or orange to brown irritant caducous bristles, margin thickened, surface with or without longitudinal ridges. Seeds 3-6 (-8), white to light yellow-brown, orange, brown, or black, sometimes mottled in various colors, elliptic, 0.9-1.78 (-2) x 0.4-1.3 cm, (3-) 4-10 mm thick; hilum 3-6 mm, ca. 1/8 of seed circumference, with aril forming a raised orange border"  (Flora of China online).

"Annual vine, grayish-pubescent; leaflets ovate to oblong, acute-acuminate, thin, pubescent-gray below, 5-13 cm long, the lateral leaflets asymmetrical; flowers purple, in drooping racemes of many flowers; each flower 3.5-4 cm long; calyx grayish-pubescent; pods stout, compressed, 5-10 cm long, 1.5 cm broad, densely pubescent, the brownish hairs easily detachable and highly irritating to skin; one longitudinal rib on each valve; seeds about 6 mm wide, compressed- ovoid, brownish with black mottling, hilum less than 3 mm long" (Stone, 1970; p. 338).

var. pruriens:  "Fruit with orange or brown irritant bristles, to ca. 1 cm wide; seeds uniform in color; terminal leaflet with length 1.5-1.75 x width, lateral leaflets of similar size; calyx often with irritant bristles"  (Flora of China online).

var. utilis:  "Fruit with long pale silky hairs, often misshapen, irregularly swollen around seeds, to 2 mm wide in parts; seeds often mottled or streaked in different colors; terminal leaflet broad, length less than or to 1.5 x width, lateral leaflets often much larger than terminal; calyx without irritant bristles"  (Flora of China online).

Habitat/ecology:  Moist tropics. "The plant can grow in a range of habitats and could become naturalised in grasslands, bushland, riverine forest and forest edges throughout tropical and subtropical regions" (Csurhes & Edwards, 1998; p. 180). In Fiji, "cultivated and sometimes sparingly naturalized at low elevations up to about 200 m" (Smith, 1985; pp. 210-211). "It can form woody thickets and smother underlying vegetation" (Smith, 2002; p. 94).

Propagation:  Seed

Native range:  Africa; from India through southeast Asia to the Philippines, widely cultivated and naturalized (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Rota Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 118)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Rota Island	introduced invasive	Space, James C./Waterhouse, Barbara/Denslow, Julie S./Nelson, Duane (2000) (p. 21)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Saipan Island	introduced invasive	Meyer, Jean-Yves (2000) (p. 101) "Forest edges"
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Saipan Island	introduced invasive	Space, James C./Falanruw, Marjorie (1999) (p. Field notes.)
Fiji Fiji Islands	Vanua Levu Island	introduced invasive cultivated	Smith, Albert C. (1985) (pp. 210-211) Mucuna pruriens subspecies pruriens var. utilis (Wight) Burck. Voucher cited: DA 16686 Sometimes sparingly naturalized.
Fiji Fiji Islands	Vanua Levu Island		Bishop Museum (Honolulu) (1969) (voucher ID: BISH 32844) Taxon name on voucher: Mucuna pruriens var. utilii (Wall. ex Wright) Bak. ex Burck
Fiji Fiji Islands	Vanua Levu Island		Bishop Museum (Honolulu) (1969) (voucher ID: BISH 32845) Taxon name on voucher: Mucuna pruriens var. utilii (Wall. ex Wright) Bak. ex Burck
Guam Guam Island	Guam Island	introduced	Stone, Benjamin C. (1970) (p. 338) Present status unknown.
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 118)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced cultivated	Imada, Clyde T./Staples, George W./Herbst, Derral R. (2011) (p. Voucher specimens) Var. utilis (Wright) Burck. Vouchers cited: Kopf s.n. (BISH 11037, BISH 666753, BISH 666754)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced cultivated	MacKee, H. S. (1994) (p. 87) Forma utiis (Wall. ex Wight) Back.; vouchers cited: Pancher C 17 s.loc., Mieillard 2561, Mme. Leenhardt s.n., De la Chapelle in MacKee 41982
New Guinea (Indonesia and Papua New Guinea) New Guinea Island	New Guinea Island	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 43-44)
Papua New Guinea Bismarck Archipelago	Bismarck Archipelago	native	ILDIS Co-ordinating Centre (2011)
Papua New Guinea Bismarck Archipelago	Bismarck Archipelago		Peekel, P. G. [translated by E. E. Henty] (1984) (p. 250) Frequent, on the foreshore and on river banks, in dry river beds and overgrown plantations; also on dry soil. The irritant hairs cause severe itching. The variety utilis has been introduced and is occasionally cultivated.
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1923) (p. 309) In dry thickets and secondary forests at low altitudes.
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 92)

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)	Queensland	introduced cultivated	Csurhes, S./Edwards, R. (1998) (p. 180)
Cambodia Cambodia	Cambodia (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
China China	China (People's Republic of)	native cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011) var. pruriens. "Forests, riversides, thickets, tall scrub, roadsides, also cultivated; below 1700 m". Var. utilis, introduced, cultivated.
Colombia Colombia	Colombia (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 241)
Costa Rica Costa Rica	Costa Rica (Republic of)	uncertain if native	ILDIS Co-ordinating Centre (2011)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 241)
El Salvador El Salvador	El Salvador (Republic of)	uncertain if native	ILDIS Co-ordinating Centre (2011)
Guatemala Guatemala	Guatemala (Republic of)	uncertain if native	ILDIS Co-ordinating Centre (2011)
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 43-44)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Japan Japan	Japan (country)	introduced	ILDIS Co-ordinating Centre (2011)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Mexico Mexico	Mexico (United Mexican States)	native	ILDIS Co-ordinating Centre (2011)
Panama Panama	Panama (Republic of)	uncertain if native	ILDIS Co-ordinating Centre (2011)
Taiwan Taiwan	Taiwan Island	native cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011) var. pruriens. "Forests, riversides, thickets, tall scrub, roadsides, also cultivated; below 1700 m". Var. utilis, introduced, cultivated.
Thailand Thailand	Thailand (Kingdom of)	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 43-44)
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)

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) Christmas Island Group	Christmas Island	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 43-44)
Australia (Indian Ocean offshore islands) Christmas Island Group	Christmas Island	native	Orchard, Anthony E., ed. (1993) (p. 18)
Comoros Comoro Islands	Comoro Islands	introduced	ILDIS Co-ordinating Centre (2011)
La Réunion (France) La Réunion Island	La Réunion Island	introduced	ILDIS Co-ordinating Centre (2011)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	introduced	ILDIS Co-ordinating Centre (2011)
Seychelles Seychelles Islands	Seychelles Islands	introduced	ILDIS Co-ordinating Centre (2011)

Comments:  Commonly used as a cover crop and the pods and beans are used to feed livestock. For information on the use of this and similar species in agriculture, see "Cover Crops in Hillside Agriculture: Farmer Innovation with Mucuna".

A weed species in Mexico, Mozambique, Jamaica and Madagascar (Waterhouse & Mitchell, 1998; pp. 43-44).

The utilis variety commonly used in agriculture lacks irritating hairs.

Additional information:
Additional online information about Mucuna pruriens is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Mucuna pruriens as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Mucuna pruriens may be available from the Germplasm Resources Information Network (GRIN).

References:

Bishop Museum (Honolulu). 1969. Voucher specimen #BISH 32844 (JWP 16686).

Bishop Museum (Honolulu). 1969. Voucher specimen #BISH 32845 (JWP 16686).

Buckles, D./Triomphe, B./Sain, G. 2005. Cover Crops in Hillside Agriculture: Farmer Innovation with Mucuna. International Development Research Centre . 230 pp.

Cardenas, Juan/Reys, Carlos E./Doll, Jerry D./Pardo, Fernando. 1972. Tropical weeds; malezas tropicales, vol. 1. International Plant Protection Center, Oregon State University, Corvallis. 341 pp.

Csurhes, S./Edwards, R. 1998. Potential environmental weeds in Australia: Candidate species for preventative control. Canberra, Australia. Biodiversity Group, Environment Australia. 208 pp.

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1979. A geographical checklist of the Micronesian dicotyledonae. Micronesica 15:1-295.

Hancock, I. R./Henderson, C. P. 1988. Flora of the Solomon Islands. Research Bulletin No. 7. Ministry of Agriculture and Lands, Honiara. 203 pp.

Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. 1979. A geographical atlas of world weeds. John Wiley & Sons, New York. 391 pp.

ILDIS Co-ordinating Centre. 2011. International Legume Database & Information Service. Online searchable database.

Imada, Clyde T./Staples, George W./Herbst, Derral R. 2011. Annotated Checklist of Cultivated Plants of Hawai‘i (online searchable database).

MacKee, H. S. 1994. Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie. Muséum National d'Histoire Naturelle, Paris, 164 p.

Merrill, Elmer D. 1923. An enumeration of Philippine flowering plants, vol. 2 [reprint]. Bureau of Printing, Manila. 530 pp.

Meyer, Jean-Yves. 2000. Preliminary review of the invasive plants in the Pacific islands (SPREP Member Countries). In: Sherley, G. (tech. ed.). Invasive species in the Pacific: A technical review and draft regional strategy. South Pacific Regional Environment Programme, Samoa. 190 pp.

Orchard, Anthony E., ed. 1993. Flora of Australia. Vol. 50, Oceanic islands 2. Australian Government Publishing Service, Canberra.

Peekel, P. G. [translated by E. E. Henty]. 1984. Flora of the Bismarck Archipelago for naturalists. Office of Forests, Division of Botany, Lae, Papua New Guinea. 638 pp. ISBN 9980-66-000-7.

Porcher, Michel H. 2011. Searchable World Wide Web Multilingual Multiscript Plant Name Database. The University of Melbourne, Australia. Online resource.

Smith, Albert C. 1985. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 3. 758 pp.

Smith, Nicholas M. 2002. Weeds of the wet/dry tropics of Australia - a field guide. Environment Centre NT, Inc. 112 pp.

Space, James C./Falanruw, Marjorie. 1999. Observations on invasive plant species in Micronesia. USDA Forest Service, Honolulu. Report to the Pacific Islands Committee, Council of Western State Foresters. USDA Forest Service, Honolulu. 32 pp.

Space, James C./Waterhouse, Barbara/Denslow, Julie S./Nelson, Duane. 2000. Invasive plant species on Rota, Commonwealth of the Northern Mariana Islands.  USDA Forest Service, Honolulu. 31 pp.

Stone, Benjamin C. 1970. The flora of Guam. Micronesica 6:1-659.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Waterhouse, B. M./Mitchell, A. A. 1998. Northern Australia Quarantine Strategy: weeds target list. Second edition. Australian Quarantine & Inspection Service, Miscellaneous Publication No. 6/98. 110 pp.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).