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Book cover - Common Weeds of New ZealandAn Illustrated Guide to
Common Weeds
of New Zealand

 

Cirsium vulgare
Scotch thistle

Family ASTERACEAE

Reproduced from
Common Weeds of New Zealand
by Ian Popay, Paul Champion & Trevor James
ISBN 0 473 09760 5
by kind permission of the
New Zealand Plant Protection Society

Publication or other use of images or descriptive text on these pages is unauthorised unless written permission is obtained from the authors and publisher.
Appropriate acknowledgement of the publication Common Weeds of New Zealand must always be given.

Available from Touchwood Books

Cirsium vulgare - Scotch thistle

Stout, well-branched biennial thistle that grows from a rosette that can be very large, to a well-branched 'shrub' up to 1.5 m tall under fertile conditions. Composite flower heads up to 5 cm across, purple-coloured, later producing seeds with a mass of pappus hairs or thistledown. Leaves are hairy on both surfaces, and have spines on the upper surface. Probably the most common thistle in New Zealand.

  • Flowers Reddish-purple, up to 6 cm long by 5 cm across, solitary or in two- or three-flowered terminal clusters. Outer bracts (small green, leaf-like structures forming the outside of the flower heads) slightly woolly-hairy, each with a strong spine about 4 mm long. Flowers Nov-Mar.
  • Fruit Narrow, egg-shaped, pale achenes about 4 mm long by 1.5 mm across, each with a feathery pappus 20-25 mm long.
  • Leaves Dark green, to 30 cm long by 10 cm wide, prickly-hairy on upper surface, white-cottony on underside. Deep lobes tipped with strong spines. On flowering stem, lower leaves are stalked and those further up are stalkless.
  • Stems Stout, erect, furrowed, branched, with spiny wings.
  • Roots Long fleshy taproot.

Habitat

Pasture, waste places, arable land, disturbed forest and road-sides.

Distribution

Widespread throughout New Zealand. Originally from Eurasia and north Africa.

Comments

One of the most abundant thistles in NZ. In pasture it seems to be strictly a biennial, germinating in winter or spring, surviving its first summer as a rosette and then flowering in its second summer. It is rarely eaten by sheep or cattle, but goats will graze it once it has started to flower. Appears in very large numbers after fire or soil disturbance. Subject to a Pest Plant Management Strategy in one or more regions. Check with the regional council for details.

Related species

The woolly-headed thistle (Cirsium brevistylum) has wingless stems with cobwebby hairs, leaves with woolly undersides, uncommon in grassland, river flats and waste ground in southern NI.

Derivation of botanical name

Cirsium Gr. name for thistle; vulgare (Lat.) = common.

Web-notes: Weed Links

On this site

Reproduced from Common Weeds of New Zealand:

External Links

WeedbustersWeedbusters New Zealand
Weedbusters is a weeds awareness and education programme that aims to protect New Zealand's environment from the increasing weed problem.
PestWebNZ™
A free tool to assist farmers and agricultural professionals in decision-making regarding weed and pest identification, biology, impact and management.
Weed keyNew Zealand Weeds Key
An interactive identification key to the weeds of New Zealand. Developed at Landcare Research.

New Zealand Plant Conservation Network naturalised plants
Search for information on more than 2500 naturalise and weedy plants.
NZ Plant Protection SocietyNew Zealand Plant Protection Society
Their main objective: "To pool and exchange information on the biology of weeds, invertebrate and vertebrate pests, pathogens and beneficial organisms and methods for modifying their effects."
 
Massey UniversityMassey University Weeds Database
A site providing information about New Zealand weeds and weed control. It has a series of pages showing pictures of New Zealand weeds, notes on identification and control. It also provides information on a university paper entitled Controlling Weeds.
 

 
 
 
Weeds in Australia
Weeds website of the Australian Government.
Weed Society of Victoria
Promoting wider awareness and interest in weeds and their management. Includes a useful page of links to other weed societies.
 
Tamar Valley Weeds Strategy
Listing of common and botanical names, images, and information including control methods for weeds found in Tasmania, and also weeds of national significance.
 

Invasive and Exotic Species of North America
Images and other information from the University of Georgia.

World of Weeds
Weed-related resources including weed science, practical tools, gardening tips about controlling weeds, and environmental news updates.
 
Invasive Species Specialist Group
"The ISSG aims to reduce threats to natural ecosystems and the native species they contain by increasing awareness of invasive alien species, and of ways to prevent, control or eradicate them."
WeedScience
Site that includes a comprehensive collection of weed images from around the world.
 


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Last updated: July 13, 2014