Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Spilanthes sodiroi Hieron.

Habit:  herb

Description:  "Plants perennial.  Stems decumbent and rooting at nodes, green-red, 1.2-5.2 mm in diameter, glabrous to very sparsely pilose (on younger parts).  Petioles 9-44.5 mm long, glabrous to sparsely pilose, narrowly winged.  Leaf blades 7.3-86.5 mm long, 10.5-35.5 mm wide, ovate to broadly ovate, base attenuate, apex acute, glabrous above and below, margins sinuate to denticulate, sparsely hispid.  Peduncles 1.4-10.8 cm long, 0.9-2 mm in diameter, sparsely pilose.  Heads discoid, 5-8.5 mm high, 6-9.5 mm in diameter.  Receptacle 3.2-6 mm high, 1-1.2 mm in diameter apex acute.  Phyllaries 5-10, biseriate, herbaceous; outer series 4-5, narrowly to broadly ovate, 3.1-5.3 mm long, 1.1-3.8 mm wide, apex rounded to acute, margin entire to sinuate, moderately ciliate; inner series 2-5, 2.9-4.5 mm long, 1-2.7 mm wide, narrowly ovate to obovate, apex rounded to acute, margin sinuate to irregularly dentate, moderately ciliate.  Pales 3-3.8 mm long, 0.4-0.6 mm wide, apex rounded to acute, stramineous.  Disc florets 68-218; corollas 1.7-2 mm long, white, 5-merous; tube 0.5-0.6 mm long, 0.2-0.5 mm in diameter; throat 1.2-1.6 mm long, 0.5-0.8 mm in diameter; lobes 0.2-0.5 mm long, 0.2-0.3 mm wide; stamens 0.9-1.3 mm long, anthers black; style 1.4-1.7 mm long, the branches 0.3-0.6 mm long; achenes 1.4-1.9 mm long, 0.4-0.8 mm wide, glabrous to moderately ciliate with straight-tipped hairs, frequently with a very narrow cork-like stramineous margin, lacking shoulders; pappus absent".

"Morphologically, this species is most closely related to the Galapagos endemic, A. darwinii.  Acmella sodiroi can be easily separated from that species by the following characteristics:  1) ovate leaves with attenuate bases vs. deltoid leaves with truncate bases; 2) vegetative parts glabrous to sparsely pilose vs. sparsely to moderately hirsute; 3) large heads (5-8.5 mm high and 6-9.5 mm in diameter vs. 5.2-6 mm high and in diameter); 4) florets more numerous (68-218 vs. 87-90) with longer, 5-merous corollas (1.7-2 mm vs. 1.2-1.4 mm); 5) longer stamens (0.9-1.3 mm vs. 0.6-0.7 mm); and 6) longer achenes (1.4-1.9 mm vs. 1.2-1.5 mm), which have a narrow, cork-like margin" (Jansen, 1985; pp. 44-45).

Habitat/ecology:  "In moist tropical and subtropical forests and especially common along streams and cultivated areas such as banana plantations; 400-3000 m"  (Jansen, 1985; pp. 44-45).

Propagation:  Seed

Native range:  "Widespread throughout Ecuador and extending north into Valle, Colombia, and south to Tumbes, Peru" (Jansen, 1985; pp. 44-45).

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) Pinta Group	Pinta Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced invasive	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
Colombia Colombia	Colombia (Republic of)	native	Jansen, Robert K. (1985)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	Jansen, Robert K. (1985)
Perú Perú	Perú (Republic of)	native	Jansen, Robert K. (1985)

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

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

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

References:

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Charles Darwin Research Station. 2005. CDRS Herbarium records.

Jansen, Robert K. 1985. The systematics of Acmella (Asteraceae-Heliantheae). Sys. Bot. Monogr. 8:1-115.