Perennial Sowthistle
Sonchus arvensis • Class C |
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Family Name: | Asteraceae (ass-ter-AR-see-ee) | |
Common: | Field sowthistle, Creeping sowthistle | |
Genus: |
Sonchus (SON-chus) Meaning: From the Greed sonchos, meaning hollow in reference to the stem |
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Species: |
Arvensis (Ar-VEN-sis) Meaning: Of farmed or cultivated land |
Description: |
Despite the name, Perennial sowthistle resembles dandelions more than it does true thistles. Perennial sowthistle usually grows 2 to 4 feet high and has an extensive root system that grows up to 10 feet deep and can spread more than 6 feet in one growing season. It has erect, hollow stems with bitter, milky juice. Its leaves vary in size and are alternate, prickly edged, and lance shaped. Flower heads are 1 to 2 inches across and bright yellow. Its bracts are green with white margins and covered with tiny hairs. |
Why Is it a Noxious Plant? |
P.S. is an aggressive spreader, a single plant can produce 4,000 to 13,000 seeds that can remain dormant in the soil for up to 6 years. It can be hard to get rid of, because even small pieces of the extensive root system can regenerate new plants. |
Where Does it Grow? |
Perennial sowthistle is found cultivated fields, waste areas, meadows, sloughs, woods, lawns, roadsides, beaches, ditches and river and lake shores. |
Facts: |
Perennial sowthistle can form dense monocultures by the spread of its rhizome-like roots. At high densities perennial sowthistle can drastically reduce water resources and likely decreases native plant diversity and is a problem in several crops, where it causes economic losses due to reduced crop yields increased expenses, and land depreciation. It is also a host of several economically damaging plant pests. |
Control Options: |
As with all invasive species, the best control measure for Perennial sowthistle is prevention. Preventing the establishment of infestations is the most time and cost effective way of controlling this species. Above all, prevent plants from going to seed.
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More Information: |
Download our Flyer or visit Washington State Noxious Weed Control Board Here. Photo by Leo Michels
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