Scientific NameSonchus asper
Synonyms (former Scientific Names):
Annual sowthistle is a summer annual plant which can grow up to 5 feet in height. It blooms from late spring through early fall and reproduces by means of seeds.
The parachute of the seeds has allowed for the wide spread dispersal of annual sowthistle. Among its defining characteristics are stiff, spined leaves which clasp at the stem.
Flower Seed Head
The flowers of annual sowthistle are yellow in color and approximately 1 inch in diameter. They bloom from late spring through early fall.
The seeds of annual sowthistle are, on average, 3 mm long and 2 mm wide. They are tan in color and have a small parachute of hairs which allows for easy dispersal.
Annual sowthistle has spread throughout the majority of the United States. It is also present in many other countries, including in Europe and the rest of North America.
upright and nonwoody
Thorns or Spines
Approximate Flower Diameter
Dominant Flower Color
Stem Cross Section
round or oval