Dorstenia contrajerva L., Moraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 9 (Go to the risk assessment)

Common name(s): [more details]

English: snakewort, tusilla

French: herbe aux serpents, herbe-chapeau, racine de charchis

Spanish: cabalhau, cambahan, contaúl, contra de cobra, contrahierba, contrayerba, hierba de loro, hierba de sapo, mano de león, xcambalhan

Habit:  herb

Description: 

Genus:  "Perennial herbs with milky sap, with rhizomes, acaulescent or with somewhat elongate stems; leaves very variable, usually long-petiolate, mostly membranaceous, entire, dentate, angulate, or pinnate-lobate; flowers minute, monoecious, densely crowded on a usually large, explanate, commonly saucer-like, entire or angulate or lobate receptacle, the receptacles axillary, long-pedunculate, the flowers of both sexes numerous and intermixed, the pistillate flowers usually surrounded each by 3-4 staminate ones, the bracts minute and inconspicuous; perianths commonly connate with the receptacle, their margins sometimes obscurely bilobate or bidentate; stamens 2, rarely 1 or 3, the filaments at first inflexed, finally porrect and exserted; ovary included, the style excentric or almost lateral, exserted, 2-fid, the short branches subulate; fruits very small, finally protruded from the pits of the receptacle, the exocarp fleshy, the endocarp crustaceous; testa of the seed thin-membranaceous; endosperm none; cotyledons subequal, embracing the ascending radicle"  (Standley & Steyermark, 1946; p. 27).

Species:  "Plants acaulescent or nearly so, the stems, if any, very short; leaves often very numerous and crowded, long-petiolate, deeply and pinnately or almost palmately lobate, sparsely scabrous or puberulent, usually somewhat rough to the touch, the lobes acute to acuminate, narrow or broad; receptacles on long slender peduncles, quadrangular or deeply and irregularly lobate, accrescent in age and 2-5 cm. wide, scaberulous beneath"  (Standley & Steyermark, 1946; p. 27).

Habitat/ecology:  In Guatemala (native), "moist forest or thickets, ascending from sea level to about 1,800 meters"  (Standley & Steyermark, 1946; p. 27).  In Florida (U.S.), "moist, disturbed sites; 0-20 m"  (Flora of North America online).

Propagation:  Seeds, explosively expelled  (Flora of North America online).

Native range:  Mexico through Central America and the Caribbean Islands to northern South America (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
State of Hawaii Hawaiian Islands	O‘ahu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1999) (voucher ID: PTBG 28338) Taxon name on voucher: Dorstenia contrajerva L.
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands	introduced	Toyoda, Takeshi (2003) (p. 464)
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands	introduced	Kato, Hidetoshi (2007)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Central America Central America (Pacific rim)	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	El Salvador (Republic of)	native	Standley, Paul C./Steyermark, Julian A. (1946) (pp. 28-29)
Central America Central America (Pacific rim)	Guatemala (Republic of)	native	Standley, Paul C./Steyermark, Julian A. (1946) (pp. 28-29)
Central America Central America (Pacific rim)	Honduras (Republic of)	native	Standley, Paul C./Steyermark, Julian A. (1946) (pp. 28-29)
Central America Central America (Pacific rim)	Nicaragua (Republic of)	native	Standley, Paul C./Steyermark, Julian A. (1946) (pp. 28-29)
Central America Central America (Pacific rim)	Panama (Republic of)	native	Standley, Paul C./Steyermark, Julian A. (1946) (pp. 28-29)
Indonesia Indonesia	Indonesia (Republic of)	introduced cultivated	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Malaysia Malaysia	Malaysia (country of)	introduced cultivated	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico Mexico	Mexico (United Mexican States)	native	Standley, Paul C./Steyermark, Julian A. (1946) (pp. 28-29)
Singapore Singapore	Singapore (Republic of)	introduced cultivated	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009)
South America (Pacific rim) South America (Pacific rim)	Colombia	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim) South America (Pacific rim)	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Guayas, Manabi
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) San Martin

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	USA (Florida)	native	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Control:  If you know of control methods for Dorstenia contrajerva, please let us know.