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 An
Illustrated Guide to
Common Weeds
of New Zealand
Cirsium
vulgare
Scotch
thistle
Family
ASTERACEAE
Reproduced from
Common
Weeds of New Zealand
by Bruce Roy, Ian Popay, Paul Champion, Trevor James & Anis
Rahman
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 Manaaki-Whenua
Press and Touchwood
Books
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
 Weedbusters
New Zealand
- Weedbusters is a weeds awareness and education programme that aims to
protect New Zealand's environment from the increasing weed problem.
 New
Zealand Plant Conservation Network Weeds Fact Sheets
- Search for 1500 weed fact sheets mainly derived from the Department of
Conservation's BIOWEB weeds database.
 New
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."
-
 New
Zealand Landcare Trust
- Plant Pest information including Pictures, Distribution Maps, References,
Environmental Effects and Control.
-
- New
Zealand Aquatic Weeds
- Hosted by the weed management group of NIWA (National Institute of Water
and Atmospheric Research).
-
- Weed
Control Manual for the Bay of Plenty
- Weeds information compiled by Environment Bay of Plenty.
-
 Massey
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.
-
- Canterbury
Weed Guide
- A weed identification guide prepared by the Christchurch City Council.
-
- Australian
Plants as Weeds
- Part of the Association of Societies for Growing Australian Plants website.
- Department
of Agriculture Western Australia
- Collection of weed resources from the Department of Agriculture, Government
of Western Australia
- 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 on the Australian
mainland.
-
-
- New
Jersey Weed Gallery, USA
- Listing of common and botanical names and images, plus a small amount
of information for weeds that cause problems in the USA.
- Invasive
and Exotic Species of North America
- Images and other information from the University of Georgia.
- University
of California
- Weed Photo Gallery, with common and botanical names.
-
- 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."
-
- Invasive
Woody Plants
- Collection of research and associated literature for invasive woody plants
in the tropics and the temperate zone.
-
- WeedScience.com
- Site that includes a comprehensive collection of weed images from around
the world.
-
-
 Books
on Weeds from FetchBook.Info
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