Screen Shot 2014-05-15 at 1.00.56 PM

These plants either have limited populations in the Southern Interior, or have not yet established here yet but are close to our management borders. They are extremely invasive, and are top priority in our management programs. If you have seen any of these plants within the Thompson-Nicola region, please report it to the SIWMC coordinator.

By clicking on the weed images, you will be linked to WeedsBC, where you can see corresponding drawings, descriptions, impacts, damage and links to management strategies.

perennial pepperweed1511258



Perennial pepperweed 

(Lepidium latifolium)

  • creeping rooted perennial introduced from southern Europe and western Asia
  • white flower clusters
  • waxy leaves showing prominent white mid-vein
  • stalkless leaves do not clasp the stem
  • forms dense monocultures in a variety of habitats
rush skeletonweed2

Rush skeletonweed

(Chondrilla juncea)

Perennial from Eurasia

  • leaves are very small
  • small yellow flowers are scattered along the branch
  • petals have toothed tips
  • spreads by airborne seeds and extensive deep roots
  • downward hairs at base of stem

field scabious-becky21511127

Field scabious

(Knautia avensis)

  • taprooted perennial from Eurasia and North America
  • violet-blue flowersleaves reduced near tip of stem
  • hairy stems and leaves
  • very similar to many ornamental species
  • very competitive weed that can form dense colonies in riparian areas and on rangelands and pastures

marsh plume thistle 

Marsh plume thistle

(Cirsium palustre)

  • introduced from Europe
  • biennial that germinates in the first year
  • grows up to 2m tall
  • typically in a single, slender unbranched stem with a cluster of purple flowers at the top
  • the upright stem is evenly covered in spiny wings
  • populations have been increasing recently in east-central BC

yellow starthistle21511128

Yellow starthistle

(Centaurea solstitialis)

  • Annual taprooted, heavily branched weed
  • typically grows from 0.6 to 1 metre tall
  • stems are winged and covered with fine hair
  • yellow flowers are borne on ends of branches and armed with sharp thorns up to 2cm long
  • not currently known in British Columbia but close to our borders with Washington and Idaho

scotch thl

Scotch thistle

(Onopordum acanthium)

  • woody, branched stems
  • long, spin-edged wings running up the sides
  • numerous, large, bright violed to reddish flowers supported by large spine-tipped bracts
  • wooly hairs cover large, irregular-lobed leaves that have sharp yellow spikes
  • mature plants can be up to 3m tall