Leptospermum scoparium J.R.Forst. & G.Forst., Myrtaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 20 (Go to the risk assessment)

Common name(s): [more details]

English: Manuka teatree, New Zealand tea tree, broom teatree, manuka, manuka myrtle, tea tree

Maori (NZ): manuka

Habit:  tree

Description:  "Shrubs or small trees to 2-5 m tall, bark shredding into long strips; young branches silky pubescent.  Leaves linear-lanceolate to linear-elliptic or occasionally ovate, 9-14 mm long, 1.5-4 mm wide, silky pubescent when young, soon glabrate, gladular-dotted, apex attenuate to a pungent tip.  Sepals broadly deltate, ca. 1.5-3.5 mm long, minutely tuberculate, glabrous, apex obtuse; petals pink or white, ca. 5-8 mm long, glandular-dotted.  Capsules 5-valved, 5-6 mm in diameter, slightly exserted from hypanthium"  (Wagner et al., 1999; p. 963).

Habitat/ecology:  "This small, scrubby tree forms thickets which crowd out other plants. In Hawai‘i, it has infested goat-eroded ridgetops, resulting in their stabilization.  It appears to have allelopathic activity like many other members of the Myrtaceae.  In Hawai‘i, it is found in mesic habitats between 300-700 m elevation" (Smith, 1985; p. 193).  In Hawai‘i, "extensively cultivated and now naturalized, primarily in disturbed mesic to wet forest and areas of forestry plantings, 330-1,220 m" (Wagner et al., 1999; p. 963).

Propagation:  Prolific seed producer. Seeds are dispersed by wind.

Native range:  Australia and New Zealand; also cultivated (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Cook Islands Southern Cook Islands	Rarotonga Island		Sykes, Bill (year unknown) Recorded by Cheeseman on Raemaru peak and perhaps a remnant of cultivation per Bill Sykes.
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 963)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 963)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Oppenheimer, Hank L. (2004) (p. 14) East Maui. Voucher cited: Oppenheimer, S. Perlman, J. Lau & R. Aguraiuja H70206 (BISH, PTBG)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 963)

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)	New South Wales	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia Australia (continental)	Australia (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Tasmania, Victoria
China China	Hong Kong	introduced cultivated	Wu, Te-lin (2001) (pp. 162-163)
New Zealand New Zealand	New Zealand (country)	native	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 865) "Lowland to subalpine areas in various habitats, especially open slopes, river banks, forest margins, and scrub, where it often forms the dominant vegetation".

Comments:  Other members of this genus, including L. flavescens, L. laevigatum and L. polygalifolium, are also potentially invasive. See also listing for Kunzea ericoides.

Control: 

Physical: "DOFAW, Katie Cassel (Kōke‘e Museum), and U.S. Army all reported that decapitated New Zealand tea trees do not resprout"  (Motooka et al., 2003).

Chemical: Reported to be sensitive to triclopyr (Motooka et al., 2003).