Great Mullein

Verbascum thapsus L.

Family: Scrophulariaceae

Names:

Verbascum
Thapsus
Great Mullein
Scrophulariaceae was named after the scrofula disease or king's evil which are tuberculous glands. Some plants in this family were supposed to cure the disease.

Other Names:

Aaron's rod
Blanket Weed
Flannel Weed
Tobacco Weed
Wild Tobacco

Summary:

A grey, densely hairy, robust biennial herb with a basal rosette of large, woolly, bluish green leaves and a flowering spike up to 2.5 metres tall with yellow, 5 petalled flowers from January to March that form round fruit. The stem leaves run down the stem as wings.

Description:

Cotyledons:

Two.

First leaves:

Leaves:

Large and woolly.
Stipules -
Petiole - Thick and short on the rosette leaves.
Blade - Woolly, velvety, egg to lance shaped. Basal leaves to 450 mm long. Densely hairy on both surfaces with star type hairs. Smooth edges.
Stem leaves - Shorter, more elliptical, woolly, form a wing where they taper to join the stem. Uppermost leaves grade into woolly egg shaped bracts under the flower clusters.

Stems:

Erect, woolly, grey, up to 2500 mm tall, winged. Usually single stemmed but may branch near the top. Star type hairs.

Flower head:

Clusters of flowers form a dense, terminal, woolly spike up to 1000 mm long x 20-40 mm diameter with bracts.

Flowers:

Creamy yellow to almost white. Almost stalkless, 12-20 mm diameter.
Ovary - Long style.
Calyx - 5 deep, lance shaped lobes, 6-9 mm long, hairy.
Petals - 5, creamy yellow, 6-10 mm long, widely spreading.
Stamens - 5. 3 of them have filaments with white or yellowish, woolly hairs, the outer two are hairless or almost so.
Anthers - 1 celled.

Fruit:

Globular to egg shaped, capsule, 10 mm long, with many seeds. Somewhat longer than the calyx.

Seeds:

Tiny, rough surfaced.

Roots:

Key Characters:

Biennial
Densely white-woolly tormentose with star type hairs.
Leaves entire.
Leaves alternate on flowering stem or radical.
Flowers more than 3 mm long, sub sessile in a compact, woolly, bracteate spike.
Corolla yellow, rotate, large without basal spur.
Upper lip or 2 upper lobes of corolla covering the lateral lobes in bud.
Calyx 5 lobed
Long style
Stamens 5.
Anther 1 celled.
Adapted from N.T. Burbidge and J. Black.

Biology:

Life cycle:

Biennial herb. Seeds germinate in autumn and spring and it forms a large rosette in the first season. The leafy flowering stem emerges in the second summer and the plant dies after seed set.

Physiology:

Reproduction:

By seed.

Flowering times:

Summer and autumn in Western NSW.
January to March in WA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

Europe. Eurasia.
Introduced as a garden plant and has escaped.

Distribution:

ACT, NSW, QLD, SA, TAS, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate, Mediterranean.

Soil:

Plant Associations:

Significance:

Beneficial:

Ornamental

Detrimental:

The dense hairs on the plant irritate the skin and mouths of stock and humans.
Weed of roadsides, railways, pastures, streams and disturbed areas often near settlements.
Unpalatable to stock.

Toxicity:

Not recorded as toxic but hairs cause irritation.

Symptoms:

Dermatitis

Treatment:

Avoid contact. Apply soothing creams.

Legislation:

Noxious weed of Victoria and NSW.

Management and Control:

Thresholds:

Eradication strategies:

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Cretan Mullein (Verbascum creticum)
Twiggy Mullein (Verbascum virgatum)

Plants of similar appearance:

Bartsia, Kickxia and Veronica species are in the same family.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P220-221. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia).

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P323.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P600. Photo.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P216.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1259.2.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne).

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.