Roldana petasitis (Sims) R. & B., Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 12 (Go to the risk assessment)

Other Latin names:  Cineraria petasitis Sims; Senecio petasitis (Sims) DC.

Common name(s): [more details]

English: California-geranium, velvet groundsel

Habit:  shrub

Description:  "Bushy shrub to 3 m tall, pilose throughout. Leaves with petiole 7-14 cm long; lamina almost circular in outline, 6-14 cm long, 7-15 cm broad, ± cordate to truncate at base, with 9-11 shallow, somewhat triangular lobes and small, hard denticulations, palmately veined, scattered strigulose above, pale crisped-pubescent below. Capitula cylindrical, in large, compound, cymose panicles, with reduced, sessile leaf-like bracts; involucral bracts 8, narrowly lanceolate, 8-10 mm long, shortly pubescent. Outer florets 5 or 6, ligulate, 6-8 mm long, yellow; disc florets c. 15, 7-8 mm long, narrowly funnel-shaped in upper half. Cypselas narrowly cylindrical, 3-4 mm long, striate, with a narrow apical rim, glabrous; pappus hairs 6-7 mm long"  (Flora of Australia online).

Habitat/ecology:  (no habitat/ecology info known by PIER)

Propagation:  Seed

Native range:  Southern Mexico, El Salvador, Guatemala, Honduras, Nicaragua (GRIN).

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 cultivated	Australian Biological Resources Study (2011) Vouchers cited: R.O. Belcher 2673 (EMC), J. Pickard in A.N. Rodd 1402 (NSW), A.C. Beauglehole 5666 (CANB, MEL). A naturalised garden escape.
State of Hawaii Hawaiian Islands	O‘ahu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1986) (voucher ID: PTBG 1705) Taxon name on voucher: Roldana petasitis (Sims) R. & B.
State of Hawaii Hawaiian Islands	O‘ahu Island		Bishop Museum (U.S.A. Hawaii. Honolulu.) (1986) (voucher ID: BISH 539937) Taxon name on voucher: Roldana petasitis (Sims) R. & B.

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	introduced invasive cultivated	National Herbarium of New South Wales (2011) Cultivated as an ornamental, occasionally naturalized.
Australia Australia (continental)	Queensland	introduced	National Herbarium of New South Wales (2011)
El Salvador El Salvador	El Salvador (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Guatemala Guatemala	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Honduras Honduras	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Nicaragua Nicaragua	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)

Additional information:
Information from PlanNET:  New South Wales Flora Online.

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

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

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

References:

Australian Biological Resources Study. 2011. Flora of Australia Online. Australian Biological Resources Study, Canberra.

Bishop Museum (U.S.A. Hawaii. Honolulu.). 1986. Voucher specimen #BISH539937(Cory, C. 12).

National Herbarium of New South Wales. 2011. PlantNet: New South Wales Flora online. The Plant Information Network System of the Botanic Gardens Trust Version 2.0. Online resource.

National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.). 1986. Voucher specimen #PTBG1705(Cory, C. 12).

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.