Laportea aestuans (L.) Chew, Urticaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 10 (Go to the risk assessment)

Other Latin names:  Urtica aestuans L.

Common name(s): [more details]

Chinese: huo yan sang ye ma

English: West Indian woodnettle, West Indian-nettle

Spanish: picapica

Habit:  herb

Description:  "Herbs, annual, 1-10 dm, sparsely to densely pubescent with stinging hairs and stipitate-glandular, nonstinging hairs. Leaf blades broadly ovate to nearly orbiculate, 9-20 x 6-16 cm, base rounded or abruptly attenuate, auriculate, margins regularly serrate or dentate, apex short-acuminate. Inflorescences with both staminate and pistillate flowers in same panicle, or proximal panicles with staminate flowers. Staminate flowers ca. 2 mm across; tepals 4-5, equal in length; stamens 4-5, opposite tepals; filaments longer than tepals. Pistillate flowers ca. 0.7 mm; tepals 2-4, appressed, inner pair ca. 1/2 length of ovary; ovary ovoid to ellipsoid; style persistent, hooked and beaklike, ca. 0.2 mm, becoming knoblike in fruit. Achenes strongly compressed, ± orbicular, ca. 0.9 x 1.3 mm"  (Flora of North America online).

"Erect annual monoecious herb with few branches usually to 1 m; stems glandular hairy. Leaves broadly ovate, coarsely serrate, acuminate, rounded, truncate or cordate at base, with stinging hairs scattered on upper surface and on veins on lower surface; lamina 3-30 cm long; petiole 2-20 cm long. Panicle to 20 cm long, sparsely hispid, bisexual. Male flowers 4- or 5-merous; tepals c. 1.5 mm long, apically glandular hairy. Female flowers 4-merous; lateral tepals c. 0.5 mm long; dorsal tepal c. 0.25 mm long, glandular hairy; stigma minutely penicillate. Achene 1-2 mm long, partly winged, with warty depressions on faces"  (Flora of Australia online).

Habitat/ecology:  On North Keeling Island, "grows in strand forest under Pisonia grandis and Argusia argentea in coralline sand"  (Flora of Australia online).  In Taiwan, "disturbed moist places by streams in forests; 200-500 m"  (Flora of China online).

Propagation:  Seed

Native range:  "Occurs from India through SE Asia to Java and the Lesser Sunda Islands"  (Flora of Australia online). Mexico to Peru, southern tropical Africa, some Indian Ocean Islands; 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) Galápagos Islands	Galápagos Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Lau, Alex/Frohlich, Danielle (2013) (pp. 11-12) Voucher cited: D. Arukaki s.n. (BISH 752428) Found in several nurseries, possibly from potting mix.

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Central America Central America (Pacific rim)	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Panama (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim) South America (Pacific rim)	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Taiwan Taiwan Island	Taiwan Island	introduced	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
United States (west coast) United States (west coast states)	USA (California)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

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) Cocos (Keeling) Islands	Cocos (Keeling) Islands	native	Australian Biological Resources Study (2013)
La Réunion (France) La Réunion Island	La Réunion Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	USA (Florida)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Control:  If you know of control methods for Laportea aestuans, please let us know.