Conyza aegyptiaca (L.) Aiton, Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Erigeron aegyptiacum L.

Habit:  herb

Description:  "Annual erect herb up to 80 cm high. Stems rather thick, branching, striate, densely villous. Lower cauline leaves withering, the median many, obovate to oblong-lanceolate, pinnatifid to coarsely toothed tapering to amplexicaul base, densely long-villous, appearing grayish green. Inflorescence corymbose with long branches; heads terminal on peduncles 1-5 cm long, villous, about 1.5cm wide, with abundant prominent white or sordid pappus; involucral bracts many,4-seriate, linear, long-attenuate, hyaline-margined, green and densely villous along middle; ray flowers many, pistillate, with long capillary corolla half as long as the style, hidden in the abundant pappus, the disc flowers relatively few, fertile, with tubular enlarged 5-fid corolla, puberulent; receptacle depressed-globose about 2.5 mm wide. Achenes oblong, 0.5 mm long; pappus 1-seriate, the hairs coherent at base" (Walker, 1976; p. 1025).

Habitat/ecology:  A weed of waste places (Walker, 1976; p. 1025). In Papua New Guinea, "a weed of roadsides and gardens; also in natural habitats - grassland, earthslips" (Henty & Pritchard, 1975; p. 66).

Propagation:  Seed

Native range:  Tropical to subtropical Africa, Asia and Australia (Li et al.,1978; p. 838).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
New Caledonia Îles Loyauté (Loyalte Islands)	Îles Loyauté (Loyalty Islands)	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	MacKee, H. S. (1994) (p. 33) Vouchers cited: Védel s.n., Pancher 406, Pancher 459, Vieillard 2818, Vieillard 2832, Balansa 13
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	MacKee, H. S. (1994) (p. 33) Voucher cited: Pancher 459
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive	Henty, E. E./Pritchard, G. H. (1975) (p. 66) From 1200-3000 m, widely spread but not yet common.

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Taiwan Taiwan	Taiwan Island	native	Ching-I Peng, ed. (2011) "Coastal regions and waste ground, in sunny situations, not collected for more 70 years".

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 98)

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

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

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

References:

Ching-I Peng, ed. 2011. Digital flora of Taiwan (online resource).

Henty, E. E./Pritchard, G. H. 1975. Weeds of New Guinea and their control. 2nd edition. Department of Forests, Division of Botany, Botany Bull. No. 7. Lae, Papua New Guinea. 180 pp.

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.

Li, Hui-lin/Liu, Tang-shui/Huang, Tseng-chieng/Koyama, Tetsuo/DeVol, Charles E., eds. 1978. Flora of Taiwan, Volume 4. Epoch Pub. Co., Taipei. 994 pp.

MacKee, H. S. 1994. Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie. Muséum National d'Histoire Naturelle, Paris, 164 p.

Swarbrick, John T. 1997. Weeds of the Pacific Islands. Technical paper no. 209. South Pacific Commission, Noumea, New Caledonia. 124 pp.

Tassin, Jacques. 2005. Jacques Tassin (IAC-CIRAD), personal communication.

Walker, E. H. 1976. Flora of Okinawa and the southern Ryukyu Islands. Smithsonian Institution Press, Washington. 1159 pp.