Verbascum thapsus L., Scrophulariaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  yes

Common name(s): [more details]

English: Aaron's rod, big taper, common mullein, flannel mullein, flannel plant, flannelleaf, great mullein, hag taper, mullein, torches, velvet dock, velvet plant, woolly mullein

French: bouillon blanc, grande molène, molène

Spanish: gordolobo común, guardalobo

Habit:  herb

Description:  "Stout biennial herbs 3-20 dm tall in the second year, densely yellowish woolly tomentose throughout, the hairs stellate or dendritic.  Basal leaves obovate to oblanceolate, 8-50 cm long, 2.5-14 cm wide, densely yellowish or whitish woolly tomentose, margins entire to shallowly crenate; cauline leaves becoming progressively smaller toward the inflorescence, oblanceolate, sessile and decurrent on stem.  Flowers in compact, spike-like panicles, pedicels partly adnate to the stem; calyx (5-) 8-12 mm long, the lobes lanceolate; corolla yellow, rarely white, 8-15 mm long, scurfy pubescent externally, sometimes also ciliate, the hairs stellate; upper 3 staminal filaments villous with yellow hairs, the lower 2 glabrous to sparsely villous.  Capsules broadly ovoid to elliptic-ovoid, 0.7-1 cm long, densely tomentose with stellate or branched hairs"  (Wagner et al., 1999; p. 1247).

Habitat/ecology:  In Hawai‘i, "naturalized and sometimes locally common, usually in open sites, cinder cones, subalpine woodland and shrubland to alpine desert, 1,550-2,350 m" (Wagner et al., 1999; p. 1247). In New Zealand, "poor stony or gravelly pastures, screes, stony river beds, roadsides and railways, shingle river banks and beds, dry waste places, sea level to c. 1000 m" (Webb et al., 1988; p. 1205).

Propagation:  Seed

Native range:  Eurasia (Wagner et al., 1999; p. 1247).

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) Norfolk Islands	Norfolk Island	introduced invasive cultivated	Orchard, Anthony E., ed. (1994) (p. 10) "Probably introduced as a garden plant but now occasionally naturalised". Vouchers cited: W.R. Sykes NI 368 (CHR); 1898, I. Robinson (NSW)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1247) Voucher cited: L. W. Bryan s.n. (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1247) Subject of an eradication program, may no longer be present.

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	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Canada Canada	Canada (country)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Chile (continental) Chile	Chile (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 378)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 1205)
United States (west coast) United States (west coast states)	USA (Oregon)	introduced invasive	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2009)
United States (west coast) United States (west coast states)	USA (California)	introduced invasive	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2009)
United States (west coast) United States (west coast states)	USA (Washington)	introduced invasive	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2009)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	Lavergne, Christophe (2006) "Envahissant"

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast and Florida) United States (other states)	USA (Florida)	introduced invasive	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2009)

Control:  Additional control information from the Bugwood Wiki.

Physical:  "Individual plants can be killed by cutting c. 8 cm below the soil surface to remove the top of the taproot.  Cutting stands before seed set prevents dispersal and burial of seeds".  (Weber, 2003; p. 448).  "Pulling a digging out roots was effective but labor-intensive and soil disturbing (Chris Zimmer, HAVO).  Plants are best controlled during the rosette stage.  Goats browse on mullein"  (Motooka et al., 2003).

Chemical:  "Chemical control is done by spraying rosettes with 2,4-D, glyphosate or tebuthiuron.  Repeated applications may be necessary to control regrowth"  (Weber, 2003; p. 448).  "Very sensitive to metsulfuron at 0.1 oz./acre.  Young plants sensitive to 2,4-D and glyphosate.  HAVO staff have controlled mullein with glyphosate at 1% of product in water formulation in foliar application (Chris Zimmer, HAVO)"  (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).
Fact sheet from the Plant Conservation Alliance, Alien Plant Working Group
Information from the Bugwood Wiki.
Information from the Global Invasive Species Database.

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

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

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

References:

Ansari, S./Daehler, C. C. 2000. Common mullein (Verbascum thapsus): A literature review. PCSU technical report #127 (May 2000). .

Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. 1979. A geographical atlas of world weeds. John Wiley & Sons, New York. 391 pp.

Lavergne, Christophe. 2006. List des especes exotiques envahissantes a La Reunion. Unpublished manuscript (Excel file). .

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.

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

U. S. Government. 2009. Integrated Taxonomic Information System (ITIS) (on-line resource).

U.S. Dept. Agr., Agr. Res. Serv. 2009. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

U.S. Dept. Agr., Nat. Res. Cons. Serv. 2009. The PLANTS Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

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.

Weber, Ewald. 2003. Invasive plants of the World. CABI Publishing, CAB International, Wallingford, UK. 548 pp.