Delairea odorata Lem., Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat 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

Spanish: senecio

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).  "Invades sensitive and fragile bushland, suppressing the growth and germination of native species by carpeting the ground and rooting down at leaf nodes. Also grows into the forest canopy, kills trees and creates light gaps, leading to more weed invasion"  (Weeds of Blue Mountains bushland).  In Hawai‘i, "naturalized in relatively dry areas" (Wagner et al., 1999; p. 356).

Propagation:  The seeds are wind-dispersed. Also spreads vegetatively.  "Produces many tiny seeds, each equipped with a small hairy parachute, like dandelion.  Seeds sail on wind or water, well into good bushland. Often dumped on bushland edges, where it will regrow from stem fragments"  (Weeds of Blue Mountains bushland).

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)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive cultivated	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 553)
Federated States of Micronesia Kosrae Island	Kosrae Island	introduced invasive	Lorence, David H./Flynn, Timothy (2010) (p. 13) As Senecio mikanioides Otto ex Walp. Invasive
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	Lāna‘i Island	introduced invasive	Starr, Forest/Starr, Kim/Loope, Lloyd L. (2010) (p. 62) Voucher cited: Starr & Starr 070404-01 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 356, 1863)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Lau, Alex/Frohlich, Danielle (2012) (p. 9) Voucher cited: OED 2009051206 (BISH). "Efforts to control this population are underway".

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. (2011)
Australia Australia (continental)	New South Wales	introduced invasive	Harley, Barbara (2009)
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:  "Easiest controlled at flowering, when highly visible and before seed is produced"  (Weedbusters New Zealand).

Physical: "Hand pull small plants, or dig out roots (all year round). Leave on site to rot down"  (Weedbusters New Zealand).

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).

"1. Stump swab (all year round): glyphosate (100ml/L) or metsulfuron-methyl 600g/kg (1g/L). Leave on site to rot down. 2. Cut stems below waist height, spray below this point (spring-summer to actively growing plants): glyphosate (10ml/L (knapsack) or 2L/100L (spraygun)) or metsulfuron-methyl 600g/kg (2g/10L (knapsack) or 20g/100L (spraygun)) or Tordon Brushkiller (60ml/10L) or Banvine (12ml/L) or Yates Woody Weedkiller (24ml/L) or amitrole (150ml/15L (knapsack) or 2L/100L (spraygun)). Add penetrant to all mixes"  (Weedbusters New Zealand).

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

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

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

References:

Atkinson, Rachel/Sawyer, John. 2011. Naturalized species in the Juan Fernández Archipelago, Chile. Unpublished spreadsheet.

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

Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido. 2006. Nouveau catalogue de la flore vaculaire de l'archipel Juan Fernández (Chile) [Nuevo catálogo de la flora vacular del Archipélago Juan Fernández (Chile)]. Acta Bot. Gallica 153(4):399-587.

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

Lau, Alex/Frohlich, Danielle. 2012. New plant records from O‘ahu for 2009. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2011. Part II: Plants. Bishop Museum Occasional Papers. 113:7-26.

Lorence, David H./Flynn, Timothy. 2010. Checklist of the plants of Kosrae. Unpublished checklist. National Tropical Botanical Garden, Lawai, Hawai‘i. 26 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.

Starr, Forest/Starr, Kim/Loope, Lloyd L. 2010. New plant records from the Hawaiian Archipelago. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2008. Bishop Museum Occasional Papers 107:61-68.

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. 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.