Cosmos bipinnatus Cav., Asteraceae

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Present on Pacific Islands?  yes

Threat only at high elevations?  no

Common name(s): [more details]

English: cosmos, Mexican aster

Spanish: girasol morado, mirasol

Habit:  herb

Description:  "Erect annual, (15)-30-110 cm tall.  Stems moderately to densely clothed in short hairs, becoming glabrous below, striate, much-branched above to form inflorescence.  Leaves shortly petiolate or subsessile, ovate-triangular, (1)-2-pinnate, (2)-3-12 cm long, leaflets glabrous or sparsely clothed in short hairs and ciliolate, usually linear, rarely narrow-lanceolate, 5-30 mm long.  Upper cauline leaves becoming smaller and apetiolate.  Capitula (25)-45-90 mm diameter, in loose cymes; peduncles glabrous or sparsely hairy.  Outer involucral bracts foliaceous, glabrous, green with darker lines, ovate-oblong with extended acuminate apex; inner bracts membranous, pale green to brown with dark lined centre and pale margins, ovate-triangular, obtuse to acute.  Receptacular scales membranous, acuminate.  Ray florets (4)-7-9; ligules pale to deep mauve-pink, pine or white.  Disc florets numerous, yellow.  Achenes (3)-4-angled, fusiform with attenuated beak, brown, glabrous except for short antrorse hairs toward apex, 5-12 mm long; pappus 0"  (Webb et al., 1988; pp 215-216).

Habitat/ecology:  "Waste places, riverbeds" (Webb et al., 1988; pp 215-216).

Propagation:  Seed

Native range:  Southern USA, Mexico, Costa Rica and Guatemala; cultivated and naturalized elsewhere (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) Santa Cruz Group	Santa Cruz Island	introduced cultivated	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
Australia Australia (continental)	Australia (continental)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 101)
Costa Rica Costa Rica	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Guatemala Guatemala	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
New Zealand New Zealand	New Zealand (country)	introduced invasive cultivated	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (pp. 215-216) "Waste places, riverbeds". Escape from cultivation

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 cultivated	Swarbrick, J. T. (1997) (p. 111)

Comments:  Reported as possibly an invasive plant in the Galápagos Islands per Charles Darwin Research Station.

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

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

References:

Charles Darwin Research Station. 2005. CDRS Herbarium records.

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.

Swarbrick, J. T. 1997. Environmental weeds and exotic plants on Christmas Island, Indian Ocean: a report to Parks Australia. 101 pp. plus appendix.

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

Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. 1988. Flora of New Zealand, Volume IV: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch. 1365 pp.