Cirpreme™ XC herbicide provides fail-safe control of the most persistent annual and perennial broadleaf weeds in wheat and barley, helping your crops to thrive. Noxious under the Ontario Weed Control Act. Perennial Sow Thistle is a perennial that is commonly confused with Annual Sow-Thistle and Prickly Lettuce. Stems can grow up to 1.5 m and leaves are found mainly at the base. Perennial sow thistle can slow harvest. The main difference between the two is that the annual sow thistle has much smaller flowers (less than 2.5 cm across) than the perennial sow thistle. Two Sonchus asper (spiny annual sow-thistle) biotypes, suspected of being resistant to the sulfonylurea herbicide metsulfuron-methyl, were collected in 1996 from two barley (Hordeum vulgare) fields in central Alberta, Canada.Both fields had received at least six applications of acetolactate synthase (ALS)-inhibiting herbicide(s). This guide covers a number of edible plants in Alberta, Canada including the Edmonton and Calgary areas and the Jasper, Banff, ... All plant parts described as being edible raw are also edible (and often more palatable) when cooked. The stems are erect, 1-4 ft. high, hollow, and glabrous. Sow thistle, Annual <