Scotch Thistle
Onopordum ancanthium • Class B |
||
Family Name: | Asteraceae family (ass-ter-AY-see-ee) | |
Common: | Aster, daisy, or sunflower family | |
Genus: |
Onopordum (On-OH-por-dum) Meaning: Donkey fodder or donkey flatulence |
|
Species: |
ancanthium (a-KANT-tee-um) Meaning: From the Greek word meaning thorny, spiny |
Description: |
Scotch thistle is a branched plant that can grow up to 8 feet or more in height and 6 feet in width. Stems have vertical rows of broad, spiny wings that extend to the base of the flower heads. Leaves are up to 2 feet long and 1 foot wide and are covered with a thick mat of cotton-like hairs that give the foliage a bluish-green look and end in a very sharp yellow spine. Its bright purple flower grows at the end of the leafy stalks as a single flower, or as a cluster of flowers. The bracts, which are one of the distinguishing features of the Scotch thistle, are yellow, sharp and needle-like. |
Why Is it a Noxious Weed? |
If eaten by stock the spines can cause injury to the animal particularly around the mouth. Spines and dead leaves contribute to faults in wool thereby decreasing its value. |
Where Does it Grow? |
Scotch thistle is confined to areas with an annual rainfall of 20 to 35 inches. It drastically reduces native plant forage by outcompeting desirable species. It can be so thick that it becomes an impenetrable thorny barrier for livestock, wildlife, and people. |
Facts: |
It is responsible for lost wildlife habitats and recreation areas. Access to trails, stream banks and fishing areas can be completely cut off by the spread of scotch thistle. |
Control Options: |
|
More Information: |
Download our Flyer or visit Washington State Noxious Weed Control Board Here. Photo by Leo Michels
|
More Pictures: |