Spermacoce exilis (L. O. Williams) C. D. Adams, Rubiaceae

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Present on Pacific Islands?  yes

Threat only at high elevations?  no

Other Latin names:  Borreria repens DC., Spermacoce mauritiana Gideon

Common name(s): [more details]

English: Pacific false buttonweed

Habit:  herb

Description:  "Annual herbs; stems decumbent, 0.2-4 dm long, usually many-branched, sparsely to densely crisped puberulent in lines on the angles.  Leaves opposite, elliptic to elliptic-lanceolate, 0.4-3.5 cm long, 0.2-1.6 cm wide, scabridulous near margins and usually crisped puberulent along principal veins on lower surface, apex acute to rounded, base cuneate, petioles 0-5 mm long, stipules ca. 2 mm long, with ca. 7 setae 1-3 mm long.  Flowers few in axillary, dense, sessile clusters, stipule-derived bracteoles with setae 1.8-2 mm long; hypanthium ca. 0.5 mm long; calyx lobes 2 (-4), 0.6-0.8 mm long, ciliate; corolla white, 0.6-0.7 mm long.  Fruit oblong, compressed, ca. 1 mm long, finely transversely wrinkled, puberulent, dehiscent. Seeds chestnut brown or yellowish brown, oblong-ellipsoid, 0.7-1 mm long, minutely reticulate, the areolae transversely wider than high" (Wagner et al., 1999; pp. 1173-1174).

Habitat/ecology:  "Disturbed areas in villages, tracksides.  Prefers moist shaded conditions but will grow in sunny sites." (Waterhouse & Mitchell, 1998; pp. 89-90).

In Hawai‘i, "recently naturalized in relatively dry areas" (Wagner et al., 1999; pp. 1173-1174).  In Fiji, "an occasional weed in villages and gardens between sea level and 200 m" (Smith, 1988; p. 373).  In Samoa, "uncommon in lawns and other sunny, disturbed places" (Whistler, 1988; p. 35).

Propagation:  "Seeds dispersed by water, human activities" (Waterhouse & Mitchell, 1998; pp. 89-90).

Native range:  "Native to Africa and Malesia, now widely naturalized in the Pacific Basin and Central and South America" (Wagner et al., 1999; pp. 1173-1174).  "Now a pantropical weedy plant, but probably of American origin and an early introduction into the Old World tropics, where it gives the appearance of being indigenous in parts of Africa, Indian Ocean islands, southeastern Asia, and Malesia" (Smith, 1988; p. 373).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Federated States of Micronesia Kosrae Island	Kosrae Island	introduced invasive	Lorence, David H./Flynn, Tim (2005) (p. 22) Voucher cited: Lorence 7855 (PTBG)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 278)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		Glassman, S. F. (1952) (p. 91) Voucher cited: Glassman 2583 (US)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	introduced invasive	Lorence, David H./Flynn, Tim (1998) (p. 28) Vouchers cited: Lorence 7902 (PTBG), Lorence 8058 (PTBG), Lorence 8098 (PTBG)
Federated States of Micronesia Yap Islands	Yap (Waqab) Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 278)
Fiji Fiji Islands	Kanathea Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Voucher cited: Bryan 571
Fiji Fiji Islands	Lakemba Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Voucher cited: Garnock-Jones 908
Fiji Fiji Islands	Ovalau Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Voucher cited: Smith 7473
Fiji Fiji Islands	Taveuni Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Voucher cited: Gillespie 4400.3
Fiji Fiji Islands	Vanua Levu Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Vouchers cited: DA 10470, DA 10767
Fiji Fiji Islands	Vanua Mbalavu Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Voucher cited: Garnock-Jones 983
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1988) (p. 373) Voucher cited: Greenwood 151, DA 9738, Smith 4319, DA 10416, DA 10180, Smith 9444, DA 9521, DA 10006, Gillespie 3424, DA 10622, Meebold 16690
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1173-1174)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Lorence, David H./Flynn, Timothy W./Wagner, Warren L. (1995) (p. 51) Vouchers cited: D. Lorence et al. 6571 (PTBG), D. Lorence & T. Flynn 6665A (PTBG), W.L. Wagner & S. Mill Arey 6429 (US), D. Lorence et al. 6575 (PTBG)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1173-1174)
Palau Palau (main island group)	Babeldaob Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 278)
Palau Palau (main island group)	Babeldaob Island	introduced invasive	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 102)
Palau Palau (main island group)	Babeldaob Island	introduced	Lorence, David H./Flynn, Tim (1998) (p. 36) Voucher cited: Lorence 8224 (PTBG)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 89-90)
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Samoa Western Samoa Islands	Western Samoa Islands		Whistler, W. A. (1988) (p. 35)
Solomon Islands Solomon Islands	Solomon Islands	introduced invasive	Smith, Albert C. (1988) (p. 373)

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	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Costa Rica Costa Rica	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Guatemala Guatemala	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Honduras Honduras	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 89-90)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Malaysia Malaysia	Malaysia (country 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)
Nicaragua Nicaragua	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Panama Panama	Panama (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Perú Perú	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)

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 invasive	Waterhouse, B. M./Mitchell, A. A. (1998) (pp. 89-90)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2007)

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

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

References:

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1979. A geographical checklist of the Micronesian dicotyledonae. Micronesica 15:1-295.

Glassman, S. F. 1952. The flora of Ponape. Bishop Mus. Bull. 209: 1-152.

Lorence, David H./Flynn, Tim. 1998. Checklist of the plants of Palau. Unpublished checklist. National Tropical Botanical Garden, Lawai, Hawai‘i. 40 pp.

Lorence, David H./Flynn, Tim. 1998. Checklist of the plants of Pohnpei. Unpublished checklist. National Tropical Botanical Garden, Lawai, Hawai‘i. 21 pp.

Lorence, David H./Flynn, Tim. 2005. Checklist of the plants of Kosrae. Unpublished checklist. National Tropical Botanical Garden, Lawai, Hawai‘i. 23 pp.

Lorence, David H./Flynn, Timothy W./Wagner, Warren L. 1995. Contributions to the flora of Hawai‘i. III. New additions, range extensions, and rediscoveries of flowering plants. In: Evenhuis, Neal L. and Miller, Scott, E., eds. Records of the Hawaii Biological Survey for 1994. Part 1: Articles. Bishop Museum Occasional Papers. 41:19-58.

Smith, Albert C. 1988. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 4. 377 pp.

Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar. 2003. Report to the Republic of Palau on invasive plant species of environmental concern. USDA Forest Service, Honolulu. 174 pp.

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

U. S. Government. 2006. Integrated Taxonomic Information System (ITIS) (on-line resource).

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

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).

Waterhouse, B. M./Mitchell, A. A. 1998. Northern Australia Quarantine Strategy: weeds target list. Second edition. Australian Quarantine & Inspection Service, Miscellaneous Publication No. 6/98. 110 pp.

Whistler, W. A. 1988. Checklist of the weed flora of western Polynesia. Technical Paper No. 194, South Pacific Commission, Noumea, New Caledonia. 69 pp.