A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Click on images to enlarge

large infestation (Photo: Forest and Kim Starr, USGS)

dense infestation in seabird nesting area in Hawaii (Photo: Forest and Kim Starr, USGS)

habit (Photo: Sheldon Navie)

leaves with sharply-toothed margins (Photo: Sheldon Navie)

close-up of leaf and younger stem, showing covering of fine whitish hairs (Photo: Sheldon Navie)

close-up of leaf underside (Photo: Sheldon Navie)

open flower-head with young flower-head enclosed in numerous green bracts (Photo: Sheldon Navie)

young flower-head with numerous deelply-toothed 'petals' (Photo: Sheldon Navie)

close-up of flower-head showing numerous yellow tubular florets (Photo: Sheldon Navie)

close-up of mature fruit (Photo: Sheldon Navie)

close-up of seeds (Photo: Steve Hurst at USDA PLANTS Database)

seedling (Photo: Sheldon Navie)

Crownbeard
Verbesina encelioides

Scientific Name

Verbesina encelioides (Cav.) Benth. & Hook. f. ex A. Gray

Synonyms

Verbesina encelioides (Cav.) Benth. & Hook. f. ex A. Gray subsp. encelioides
Ximenesia encelioides Cav.

Common Names

American dogweed, butter daisy, cowpen daisy, crown beard, crown-beard, crownbeard, gold weed, golden crown beard, golden crown daisy, golden crown -beard, golden crownbeard, skunk daisy, South African daisy, wild sunflower, yellowtop

Family

Asteraceae (Queensland, New South Wales, the ACT, Victoria, Tasmania, Western Australia and the Northern Territory)
Compositae (South Australia)

Origin

Native to North America (i.e. southern and western USA and northern and central Mexico).

Naturalised Distribution

A very widespread introduced species that is mainly found in the eastern parts of Australia. It is naturalised in southern and central Queensland, New South Wales, north-western and central Victoria, south-eastern South Australia, the coastal districts of western and northern Western Australia and the southern parts of the Northern Territory.

Habitat

A weed of pastures, creek-banks, floodplains, open woodlands, grasslands, roadsides, crops, disturbed sites and waste areas in warmer temperate, sub-tropical, semi-arid and tropical regions.

Distinguishing Features

a short-lived herbaceous plant usually growing 0.3-1.6 m tall.
its stems and younger leaves are covered in fine white hairs that give them a greyish-green appearance.
its triangular or egg-shaped leaves (4-10 cm long and 1-4 cm wide) have sharply-toothed margins.
its yellow flower-heads (2.5-5 cm across) resemble small sunflowers with about 12-15 yellow 'petals' 1-2 cm long.
its greyish-brown 'seeds' (5-8 mm long) have two broad pale coloured wings and are topped with two fine bristles (1-2 mm long).

Habit

A short-lived (i.e. annual) herbaceous plant usually growing 0.3-1.6 m tall.

Stems and Leaves

The stems are covered in fine white hairs that give them a greyish-green appearance (i.e. they are finely pubescent).

The leaves are mostly triangular or egg-shaped in outline (i.e. ovate), however the upper most ones are more elongated in shape (i.e. lanceolate). The lower leaves are paired (i.e. oppositely arranged), while the upper leaves are alternately arranged. These leaves (4-10 cm long and 1-4 cm wide) have sharply-toothed (i.e. serrate) or slightly lobed margins and are borne on short stalks (i.e. petioles). The upper and lower leaf surfaces are both covered in fine white hairs, particularly on the lower surface which have a greyish-white appearance.

Flowers and Fruit

The yellow flower-heads (2.5-5 cm across) resemble small sunflowers and are borne singly at the tops of the branches on long stalks (i.e. peduncles) up to 25 cm long. The bases of these flower-heads (i.e. capitula) are surrounded by two rows of elongated green bracts (i.e. involucral bracts). Each flower-head has about 12-15 yellow or bright yellow 'petals' (i.e. ray florets) 1-2 cm long that are deeply toothed at the tip. There are also numerous small yellow flowers (i.e. tubular or disc florets) in the centre of each flower-head. Flowering occurs mainly during spring and summer.

The brown or greyish-brown 'seeds' (i.e. achenes) are flattened, finely hairy (i.e. pubescent) and 5-8 mm long. They have two broad pale coloured wings and are topped with two fine bristles (1-2 mm long).

Reproduction and Dispersal

This species reproduces by seed, which are easily dispersed by wind and water. They may also be spread by vehicles, in soil or in contaminated agricultural produce.

Impacts

Crownbeard (Verbesina encelioides) is regarded as and environmental weed in Queensland, and as a minor or potential environmental weed in Western Australia, New South Wales and Victoria. It was recently listed as a priority environmental weed in at least one Natural Resource Management region.

Legislation

Not declared or considered noxious by any state government authorities.

Sources

Anonymous (2006). Germplasm Resources Information Network (GRIN). http://www.ars-grin.gov/cgi-bin/npgs/html/index.pl. National Germplasm Resources Laboratory, National Genetic Resources Program, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Beltsville, Maryland, USA.

Anonymous (2006). Verbesina encelioides (Cav.) Benth. & Hook. f. ex A. Gray. Golden crownbeard. Plants Profile. http://plants.usda.gov/java/profile?symbol=VEEN. Natural Resources Conservation Service, United States Department of Agriculture (USDA).

Batianoff, G.N. and Butler, D.W. (2002). Assessment of invasive naturalized plants in south-east Queensland. Plant Protection Quarterly 17: 27-34.

Coleman, H. (1997). *Verbesina encelioides (Cav.) A.Gray. FloraBase: The Western Australian Flora. http://florabase.calm.wa.gov.au. Western Australian Herbarium, Department of Conservation and Land Management (CALM), Perth, Western Australia.

Finlayson, C. and Finlayson, T. (2007). Invasive Plant Threatens Midway Atoll Seabirds. http://www.friendsofmidway.org/Verbesina_on_Midway_Atoll_Brochure.pdf. Friends of Midway Atoll (FOMA), Beaverton, Oregon. USA.

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. The Plant Protection Society of Western Australia, Victoria Park, Western Australia.

Murray, L. (2007). Verbesina encelioides (Cav.) A.Gray. New South Wales Flora Online. PlantNET - The Plant Information Network System of Botanic Gardens Trust. http://plantnet.rbgsyd.nsw.gov.au. Royal Botanic Gardens and Domain Trust, Sydney, New South Wales.

Shluker, A. (2002). HNIS Report for Verbesina encelioides.http://www.hear.org/hnis/reports/verbesina_encelioides_hnis.pdf. Harmful Non-Indigenous Species (HNIS) database. Hawaiian Ecosystems at Risk project (HEAR), Honolulu, Hawaii, USA.