Stachytarpheta mutabilis (Jacq.) Vahl, Verbenaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 12 (Go to the risk assessment)

Common name(s): [more details]

English: changeable velvetberry, pink rat tail, pink snakeweed

French: queue de rat, verveine fleurs roses

Habit:  herb

Description:  "Perennial herbs or subshrubs 10-20 (-50) dm tall; stems stout, branched, densely tomentose or villous throughout.  Leaves opposite, usually rather thick and chartaceous or somewhat leathery, ovate to elliptic-oblong, sometimes lanceolate, 5-12 cm long, 2.5-6 cm wide, upper surface often rugose and sparsely villous to scaberulous, lower surface densely tomentose or villous, margins crenate or serrate, the teeth angled forward, apex acute to acuminate, base broadly cuneate to occasionally subcordate, petioles 1-2.3 cm long.  Spikes stout, erect, 10-60 cm long, densely strigose or hirtellous, the furrows shallow, bracts lanceolate or oblong-lanceolate, 8-12 mm long; calyx somewhat compressed, 8-12 mm long, the teeth subequal, minute; corolla showy, scarlet, crimson to rose or magenta, fading pink, occasionally purple, fading blue, the tube 13-18 mm long"  (Wagner et al., 1999; p. 1322).

"Stachytarpheta mutabilis hybridizes with S. cayennensis [S. x trimeni Rech.].  The hybrids are very similar to S. mutabilis but are usually low in habit with smaller leaves that are less densely pubescent, as is the rachis, and the corolla varies from purplish pink to purple, dark purple, or dark violet"  (Wagner et al., 1999; p. 1322).

Habitat/ecology:  "Snakeweeds invade disturbed areas, e.g. creek lines and roadsides; also monsoon vine forests where soil has been disturbed by pigs and buffalo. Can invade overgrazed pastures." (Smith, 2002; pp. 42-43). In Hawai‘i, "naturalized along Powerline Trail, Hanalei valley, 90-190 m, Kaua‘i" (Wagner et al., 1999; p. 1322). In Fiji, "naturalized, probably as an escape from cultivation, in open places from near sea level to about 900 m" (Smith, 1991; pp. 168-170).

Propagation:  "Usually spread intentionally as ornamental plants.  Seeds are also dispersed on vehicles, by the movement of soil in refuse from gardens and by rainwater.  In Queensland [Australia] they have been spread in fodder, hay and in contaminated pasture seed."  (Smith, 2002; pp. 42-43).

Native range:  "Native to the Neotropics from Mexico to northern South America and the West Indies, widely naturalized elsewhere, commonly cultivated as fences or hedges" (Wagner et al., 1999; p. 1322).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Fiji Fiji Islands	Ovalau Island	introduced invasive	Smith, Albert C. (1991) (pp. 169-170) Voucher cited: Tothill 674
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1991) (pp. 169-170) Vouchers cited: Greenwood 455, Degener 15327, DA 9800, DA 9801, DA 9802, Gillespie 4418, DA 1067, DA 9901, DA 9902, DA 9105, DA 9149
French Polynesia Society Islands	Moorea Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 2090 (PAP)
French Polynesia Society Islands	Raiatea (Havai) Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 3444 (PAP) Cultivée
French Polynesia Society Islands	Tahiti Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Vouchers cited: J. Florence 2874 (PAP), J. Florence 3665 (PAP) Ornementale peu commune à Tahiti.
French Polynesia Tuamotu Archipelago	Makatea (Ma‘atea) Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 2986 (PAP)
French Polynesia Tuamotu Archipelago	Tuamotu Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Voucher cited: J. Florence 2986 (PAP)
State of Hawaii Hawaiian Islands	Hawaiian Islands	introduced cultivated	Staples, George W./Herbst, Derral/Imada, Clyde T. (2000) (p. 31)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1322)

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)	Queensland	introduced invasive cultivated	Smith, Nicholas M. (2002) (pp. 42-43)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Singapore Singapore	Singapore (Republic of)	introduced invasive	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 81) Naturalised

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	MacDonald, I. A. W./Thebaud, C./Strahm, W. A./Strasberg, D. (1991) (pp. 51-61)
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	Lavergne, Christophe (2006) "Naturalisé"
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1991) (voucher ID: PTBG 11856) Taxon name on voucher: Stachytarpheta mutabilis
Seychelles Seychelles Islands	Seychelles Islands	introduced	Invasive Species Specialist Group (2017)

Control:  If you know of control methods for Stachytarpheta mutabilis, please let us know.