Present on Pacific Islands?  yes

Threat only at high elevations?  no

Habit:  herb

Description:  "Freely branching annual mostly 3-5 (10) dm tall, the stem loosely villous or villous-hirsute, especially upward, with rather long, multicellular hairs; leaves sessile or contracted to short, more or less petiolar base, blade elliptic or nearly rhombic to obovate or ovate, evidently to scarcely toothed, mostly 2.5-8 cm long, 1.2-4 cm wide, sparsely or moderately hirsute with more or less appressed to loosely spreading hairs shorter and firmer than those of stem, heads essentially sessile; outer involucral bracts 3-5 mm long, notably villous-ciliate on margins, less hairy or glabrous on back; "fruits" (mature inner involucral bracts) radially somewhat compressed, obtriangular in side view, resinous-glandular, and beset with stout, often apically finely hooked prickles, the body commonly 3.5-5 mm long exclusive of the 2 to several larger prickles about top"  (Wiggins & Porter, 1971; pp. 308-309).

Habitat/ecology:  "A weed of coastal Ecuador and Peru" (Wiggins & Porter, 1971; pp. 308-309).

Propagation:  Seed

Native range:  Ecuador and Peru (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	probably introduced invasive	Charles Darwin Research Station (2005)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Perú Perú	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)

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

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

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

References:

Charles Darwin Research Station. 2005. CDRS Herbarium records.

U.S. Dept. Agr., Agr. Res. Serv. 2007. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Wiggins, I. L./Porter, D. M. 1971. Flora of the Galapágos Islands. Stanford University Press. 998 pp.