Delairea odorata Lem., Asteraceae

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Present on Pacific Islands?  yes

Threat only at high elevations?  no

Risk assessment results:  High risk, score: 14 (Go to the risk assessment)

Other Latin names:  Senecio mikanioides Otto ex Walp.

Common name(s): [more details]

English: African ivy, Cape ivy, climbing groundsel, German ivy, Italian ivy, parlor ivy

Habit:  vine

Description:  "Fleshy perennial vines, woody at least below; stems 1-30 (- 60) dm long, glabrous throughout.  Leaves broadly deltate, blades 3-10 cm long, 3-6 cm wide, palmately veined, shallowly 3-10-lobed, petioles 1.5-7 cm long.  Heads in dense terminal and axillary cymes, discoid; involucral bracts 3-4 mm long; disk corollas yellow, ca. 4.5 mm long.  Achenes ca. 2 mm long"  (Wagner et al., 1999; p. 356).

A perennial, bushy vine that can cover vegetation to a considerable height.  Leaves are leathery, fleshy, lobed and generally cordate-hastate.  The stems are green or purple.  In spring, the plant is covered with yellow flowers (Csurhes & Edwards, 1998; p. 155).

Habitat/ecology:  Dry forest, moist forest, coastal areas. "This noxious, light-loving vine grows rapidly into the emergent layers of forests where it festoons the vegetation.  It can smother native vegetation and affect regeneration.  Senecio grows in open, wet habitats, generally above 800 m" (Smith, 1985; pp. 202-203).  In Hawai‘i, "naturalized in relatively dry areas" (Wagner et al., 1999; p. 356).

Propagation:  The seeds are wind-dispersed. Also spreads vegetatively.

Native range:  South Africa.

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 18) "Perhaps a recent escape from cultivation which will need to be watched as it has proved to be a serious pest in, for example, parts of Hawai‘i". Voucher cited: P.S. Green 2339 (K)
Federated States of Micronesia Kosrae Island	Kosrae Island	introduced invasive	Lorence, David H./Flynn, Tim (2005) (p. 12)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		Lorence, David H./Flynn, Tim (1998) (p. 16) Reported present but not seen.
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 356, 1863) Voucher cited: Rock 3412 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 356, 1863)

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	U.S. Dept. Agr., Agr. Res. Serv. (2007)
Australia Australia (continental)	Queensland	introduced invasive cultivated	Csurhes, S./Edwards, R. (1998) (p. 155)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Owen, S. J. (1997)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 275) "Waste places, scrubland, forest margins, especially in coastal areas".

Comments:  On New Zealand noxious weed list and banned from sale in that country. A weed in Australia and the US.

Control: 

Physical: Must be dug out.

Chemical: 1% Roundup + 0.2% Pulse or Tordon Brushkiller or Grazon; Banvine at 180ml per 15 l by knapsack; apply to actively growing plants (Timmins and Mackenzie, 1995; pp. 249-251).

"Asteraceae are generally sensitive to triclopyr. Probably sensitive to other hormone-type herbicides as well.  Bryon Stevens (DOFAW) recommended cutting stems of vines supported in vegetation, leaving the cut portions to dry out and spraying the foliage of the remaining plants with glyphosate.  Large patches can be controlled with the foliar glyphosate at 10% of product applied by the drizzle method, however he noted that resprouts are common and will need follow-up treatment"  (Motooka et al., 2003).

Additional information:  Information from the book "Weeds of Hawaii‘s Pastures and Natural Areas; An Identification and Management Guide" (Motooka et al., 2003). (PDF format).
Report (PDF format) from US Geological Survey, Biological Resources Division, Haleakala Field Station, Hawaii "Plants of Hawaii".
Information on the Environment Bay of Plenty, New Zealand, web site.

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

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

References:

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

Motooka, Philip/Castro, Luisa/Nelson, Duane/ Nagai, Guy/Ching, Lincoln. 2003. Weeds of Hawaii‘s Pastures and Natural Areas; An Identification and Management Guide. College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. 184 pp.

Motooka, Philip/Ching, Lincoln/Nagai, Guy. 2002. Herbicidal Weed Control Methods for Pasture and Natural Areas of Hawaii. Cooperative Extension Service, College of Tropical Agriculture and Human Resources, University of Hawai‘i. CTAHR free publication WC-8.

Orchard, Anthony E., ed. 1994. Flora of Australia. Vol. 49, Oceanic islands 1. Australian Government Publishing Service, Canberra.

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

Smith, Clifford W. 1985. Impact of Alien Plants on Hawai‘i's Native Biota. In: Stone, Charles P. and Scott, J. Michael, eds. Hawai‘i's terrestrial ecosystems: preservation and Management. Cooperative National Park Resources Studies Unit, University of Hawaii, Manoa.

Timmins, S. M./Mackenzie, I. W. 1995. Weeds in New Zealand protected natural areas database. Wellington, New Zealand. Department of Conservation, , Technical Series No. 8. 287 pp.

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).

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.