Gouania polygama (Jacq.) Urb., Rhamnaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Gouania tomentosa Jacq.; Rhamnus polygama Jacq.

Common name(s): [more details]

English: chewstick, soap vine

Spanish: canillo, jaboncilla

Habit:  herb

Description:  "Mostly vinelike with slender branches, often climbing to 5 m or more; twigs and leaves densely (or leaves rarely sparsely) brown-tomentose with stiff, spreading, simple to few-rayed hairs; stipules lance-triangular, attenuate, 3-6 mm long, ciliolate, caducous, hirsute on outer surface, subglabrate within; petioles somewhat stoutish, 5-25 mm long, tomentose or hirtellous; leaf blades ovate to broadly elliptic, obtuse, rounded or truncate at base, short-acuminate apically, 5-12 cm long, 2-6 cm wide, dark green and sparsely to moderately pubescent above, brownish and more densely tomentose beneath, margins shallowly and coarsely crenate-serrate, tip of each tooth cartilaginous; veins 4-7 on each side, arcuately curved upward, prominulous; inflorescences terminal on branchlets and axillary to upper leaves, simple or paniculately branched, the branches slender, 6-15 cm long, mostly deciduous; calyx lobes triangular, about 1 mm long and wide, tomentose without, glabrous within; petals 1-1.4 mm long, cucullate, each partially enfolding a stamen; stamens inserted near margin of calyx tube, filaments dilated basally; disk 5-lobed, conspicuous, almost equaling calyx tube, its margin often 2- or 3-toothed at tip of each lobe; fruits about 5-8 mm long, 6-12 mm broad, each coccus bearing a thin wing 1-1.5 mm wide along its outer angle, outer surface inconspicuously reticulate-veined and sparsely puberulent to glabrate on the rounded back, pale brown; seeds obovoid-compressed, about 4 mm long, 3 mm wide, brown and shining, slightly rounded abaxially, low-carinate adaxially"  (Wiggins & Porter, 1971; pp. 735-737).

Habitat/ecology:  "In shrubby or openly forested areas" (Wiggins & Porter, 1971; pp. 735-737).

Propagation:  Seed

Native range:  Mexico; Central and 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
Ecuador (Galápagos Islands) Floreana Group	Floreana Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced cultivated	Charles Darwin Foundation (2008)

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	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Panama (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
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)
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Comments:  Probably not native to the Galápagos Islands; probably introduced per Charles Darwin Research Station.

Control:  If you know of control methods for Gouania polygama, please let us know.