Sonchus arvensis, the field milk thistle, field sowthistle, perennial sow-thistle, corn sow thistle, dindle, gutweed, swine thistle, or tree sow thistle, is a species of flowering plant in the daisy family Asteraceae. When cut during cultivation, root pieces as small as 1 cm can produce a flowering plant within a year. Native to western Asia and Europe, perennial sow thistle was most likely introduced as a seed contaminant. Above In-crop weed control, as part of an integrated weed management program, can help prevent losses. > Applications & Tools This weed is a tall, creeping perennial that reproduces by seed and horizontal, underground roots. This is an invasive species able to spread long distances by wind-blown seed. Alberta.ca > Agriculture and Forestry Perennial Sow Thistle . Stems can grow up to 1.5 m and leaves are found mainly at the base. Both Rough Sow-thistle and Smooth Sow-thistle are similar, but Perennial Sow-thistle has larger, more showy and deeper yellow flowers. Perennial Sow Thistle is considered a noxious weed throughout most of its range including BC, Alberta and Alaska. Perennial sow thistle is common in cultivated areas, ditches, pastures, and undeveloped areas. Recognizable features: It was reported from Manitoba in 1919. Perennial, reproducing by seed and from buds on the widely spreading underground root system. A native of Europe introduced to North America by the transport of contaminated crops, it is now widely distributed across the northern half of the United States. Like most invasive species in Alberta it was introduced to North America from Europe and Asia. variety of sow thistle in which these hairs are absent. CANADA THISTLE Cirsium arvense PERENNIAL SOW-THISTLE Sonchus arvensis Description Name: Perennial sow-thistle (Sonchus arvensis) Classification: Noxious Recognizable features: Stem: upright, leafy at the base with Only a few leaves on the stem, up to 2 m Leaves: initially form a rosette, later become alternate, up to 20 cm long, clasp In closely related species, Spiny Annual Sowthistle (Sonchus asper) in Alberta is resistant to Group 2 herbicides and Annual Sowthistle (Sonchus oleraceus) has proven resistant in Australia to Groups 2, 4 and 9. Perennial Sowthistle reproduces both by seed and creeping roots (rhizomes. Smooth Sow-thistle has pointed leaf auricles and Rough Sow-thistle has prickly leaves. > Weeds Selector. Noxious weeds must be controlled, meaning their growth or spread needs to be prevented. S. arvensis often occurs in annual crop fields and may cause substantial yield losses. It is an aggressive agricultural weed that reduces crop yields. click to enlarge : Biology. The perennial sow thistle (Sonchus arvensis) is often confused with the annual sow thistle (Sonchus oleraceus). Choose clean fields, free of herbicide residues Perennial sow thistle ranks among the top 20 most abundant weeds in western Canada. It has yellow, dandelion-like flowers that are grouped in loose clusters at the ends of stem. Phone the Ag-Info Centre, toll-free in Alberta at 310-FARM (3276), for agricultural and forestry information. Sow thistle is a perennial weed that can grow in a wide variety of environmental conditions and is currently found in all Canadian provinces except Nunavut. The roots penetrate to a depth of 1.5-3 m (5-10 ft.). All rights reserved. top Please choose between the following three options: New mandatory public health measures are in effect across Alberta to protect the health system and slow the spread of COVID-19. Please choose between the following five options: Our strategic direction to make Edmonton a healthy, urban, climate resilient city that supports a prosperous region. Creeping sow thistle, field sow thistle, field milk thistle, gutweed, swine thistle and marsh thistle. Perennial sow-thistle seed germinates when the soil has warmed in the spring, usually mid-to late May in Alberta. The leaves have a prominent light green middle vein and spiny toothed edges. Perennial Sow Thistle . Description. I can't tell the difference myself. Leaves are alternate with slightly toothed margins. Bolting usually occurs in the second year when the rosette has 12-15 leaves. They are also taller. Perennial sow-thistle is a perennial weed reproducing by seed and by buds on underground roots. It is a perennial plant that reproduces both by seed and creeping roots (rhizomes). Annual Sowthistle is very similar to Perennial, but reproduces only by seed and its flowers are smaller. young leaves are edible raw. 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