Buddleja davidii Franch., Scrophulariaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  yes

Risk assessment results: 

Accept, score: -4 (Go to the risk assessment (Australia))
High risk, score: 13 (Go to the risk assessment (Pacific))

Other Latin names:  Buddleia davidii Franch.

Common name(s): [more details]

Chinese: da ye zui yu cao

English: buddleia, butterfly bush, orange eye, summer lilac

Habit:  shrub

Description: 

Genus "Shrubs (infrequently trees, lianas, or suffrutescent herbs), monoecious or dioecious, usually with stellate or capitate-glandular hairs, the stipules leafy or reduced to a line; leaves opposite (infrequently alternate), petiolate or sometimes sessile or connate-perfoliate, the blades frequently dentate or crenate; inflorescences often cymose-paniculate, usually many-flowered, bracteate; flowers 4-merous, actinomorphic to slightly zygomorphic; calyx campanulate, the lobes subequal; corolla cupuliform to infundibular or salverform, the lobes spreading, usually shorter than tube; stamens variously inserted on tube from base to mouth, the filaments shorter or longer than anthers, these oblong to suborbicular, usually cordate at base; ovary usually laterally compressed, 2- or 4-locular, the ovules several-many, the style included or exserted, the stigma large, clavate, capitate, or bilobed; fruit capsular or less often baccate, usually bivalved, the calyx and corolla often persistent, the seeds winged or not" (Smith, 1991; p. 74).

Species: "Shrub 1-3 m high, the fragrant flowers with lilac corollas orange-yellow in throat" (Smith, 1991; p. 74).  "Deciduous (occasionally semi-evergreen) open, multi-stemmed shrub to 3+ m tall. Stems are bluntly angled, clad in tufts of easily-removed soft woolly hair (downy hairs when young), and become lax when long. Thin, willow-shaped leaves (6-20 x 3-8 cm) are usually hairless above, white or hairy grey underneath, and finely toothed. Distinctive, dense, cone-shaped hanging clusters (30 x 5 cm) made up of many fragrant purple or white flowers (5 mm diameter) with orange insides are produced from December to February and are followed by seed capsules (5-10 mm long)"  (Weedbusters New Zealand).

Habitat/ecology:  Colonizes disturbed areas such as roadsides and riparian areas (Randall et al., 1996).  "Buddleia can grow almost anywhere, but prefers nutrient-rich watercourses and creeklines, where it quickly dominates, shading out and replacing native plant species"  (Weeds of Blue Mountains bushland).  In the Pacific, it could be a potential problem at higher elevations.  In Hawai‘i, naturalized in moist and wet open areas at 3000-5000 ft. elevation. 

In New Zealand, "has invaded streambeds, roadsides and land slips.  ...It appears to be a pioneer species and is eventually replaced by native species if disturbance is not continuous." In Australia, "riparian communities also support infestations, particularly in association with disturbance in the urban area." (Csurhes & Edwards, 1998; p. 145). In New Zealand, "riverbanks, roadsides and disturbed sites, particularly around forested areas, waste places in and around settled areas. Buddleia or butterfly bush is abundantly naturalised to the point of being a nuisance in some areas. It has spread deep into the Urewera and other remoter parts of the North Island, and tolerates a wide range of soil conditions, even growing on the almost raw lava of Rangitoto Island" (Webb et al., 1988; p. 449).

Propagation:  Wind-dispersed seeds. "Prolific numbers of small brown cylindrical fruits are produced in late summer, each tailed to aid dispersal. Seeds are mainly dispersed by wind and water, but also by machinery, vehicles, the movement of soil, and by dumping" (Weeds of Blue Mountains bushland).

Native range:  Tibet and central China, cultivated elsewhere.

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) Santa Cruz Group	Santa Cruz Island	introduced cultivated	Charles Darwin Foundation (2008)
Fiji Fiji Islands	Viti Levu Island	introduced cultivated	Smith, Albert C. (1991) (p. 74) Voucher cited: DA 16089
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Herbst, Derral R./Wagner, Warren L. (1996) (p. 13) Voucher cited: Lorence & Flynn 7452 (US) Sparingly naturalized.
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd L. (2003) (p. 26) East Maui. Voucher cited: Starr & Martz 000831-9 (BISH)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced cultivated	MacKee, H. S. (1994) (p. 94) Vouchers cited: Baumann 6798, MacKee 12298
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive cultivated	Conn, Barry J., ed. (1995) (pp. 129-131) A garden escape.

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)	Australia (continental)	introduced invasive cultivated	Csurhes, S./Edwards, R. (1998) (p. 145)
Australia Australia (continental)	New South Wales	introduced invasive	Harley, Barbara (2009)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
China China	Hong Kong	introduced cultivated	Wu, Te-lin (2001) (p. 241)
Japan Japan	Japan (country)	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 188)
Malaysia Malaysia	Malaysia (country of)	introduced invasive cultivated	Conn, Barry J., ed. (1995) (pp. 129-131) A garden escape.
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 448)
Singapore Singapore	Singapore (Republic of)	introduced cultivated	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 20) Cultivated only

Comments:  A major problem weed in New Zealand (Csurhes & Edwards, 1998; p. 145).

See also B. asiatica and B.madagascariensis.

Control:  Seed bank reinfests bared sites. Cut stumps resprout.  Difficult to prevent reinvasion. Follow up 6-monthly. Maintain rolling front.

Physical:  Pull or dig small plants. Leave on site to rot down.

Chemical:  1. Cut stump application: apply glyphosate (250ml/L) or Tordon Brushkiller (250ml/L) to horizontally cut stumps.
2. Bore and fill: drill holes sloping into the sapwood at regular intervals around the tree.  Place a mixture of glyphosate (250ml/L) or undiluted Tordon Brushkiller into each hole.
3. Frilling: with a sharp chisel or axe, make a deep cut into the sapwood at regular intervals around the base of the tree ensuring the plant is not ring-barked.   Immediately apply a mixture of glyphosate (250ml/L) or undiluted Tordon Brushkiller to the cuts using a paintbrush or squeeze bottle.
4. Weed wipe (February-April): glyphosate (333ml/L).
5. Spray (February-April): glyphosate (10ml/L) or metsulfuron-methyl 600g/kg (5g/10L) or Tordon Brushkiller (90ml/15l (knapsack) or 250ml/100L (spraygun))"  (Weedbusters New Zealand).

Additional information:
Report (PDF format) from US Geological Survey, Biological Resources Division, Haleakala Field Station, Hawaii "Plants of Hawaii".
At the Woody Plant Ecology web site.
Information from "Invasive plants of Asian origin established in the United States and their natural enemies, volume 1" (PDF format).
Information from the Global Invasive Species Database.
Information and photos at Weeds of Blue Mountains bushland.
Information sheet from Weedbusters New Zealand.

Additional online information about Buddleja davidii is available from the Hawaiian Ecosystems at Risk project (HEAR).

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

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

References:

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Charles Darwin Research Station. 2005. CDRS Herbarium records.

Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp.

Conn, Barry J., ed. 1995. Handbooks of the flora of Papua New Guinea, vol. 3. Melbourne University Press, Melbourne. 292 pp.

Csurhes, S./Edwards, R. 1998. Potential environmental weeds in Australia: Candidate species for preventative control. Canberra, Australia. Biodiversity Group, Environment Australia. 208 pp.

Harley, Barbara. 2009. Weeds of Blue Mountains bushland. (online resource).

Herbst, Derral R./Wagner, Warren L. 1996. Contributions to the Flora of Hawai‘i. V. In: Evenhuis, Neal L. and Miller, Scott, E., eds. Records of the Hawaii Biological Survey for 1995. Part 2: Notes. Bishop Museum Occasional Papers. 46:8-12.

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

Mito, Toshikazu/Uesugi, Tetsuro. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2)/2004: 171-191.

Owen, S. J. 1997. Ecological weeds on conservation land in New Zealand: A database. Working draft. Wellington, New Zealand. Department of Conservation.

Randall, J. M./Marinelli, J. (eds.). 1996. Invasive plants: weeds of the global garden. Brooklyn Botanic Garden Handbook 149. 111 pp.

Smith, Albert C. 1991. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 5. 626 pp.

Starr, Forest/Starr, Kim/Loope, Lloyd L. 2003. New plant records from the Hawaiian Archipelago. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2001-2002. Part 2: Notes. Bishop Museum Occasional Papers. 74:23-34.

U.S. Dept. Agr., Agr. Res. Serv. 2011. 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).

Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. 1988. Flora of New Zealand, Volume IV: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch. 1365 pp.

Wu, Te-lin. 2001. Check List of Hong Kong Plants. Hong Kong Herbarium and the South China Institute of Botany. Agriculture, Fisheries and Conservation Department Bulletin 1 (revised). 384 pp.

Zheng, Hao/Wu, Yun/Ding, Jianqing/Binion, Denise/Fu, Weidong/Reardon, Richard. 2004. Invasive plants of Asian origin established in the United States and their natural enemies, volume 1. FHTET-2004-05. U.S. Forest Service, Morgantown.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).