Examples of biennial broadleaf weeds are:

• A. Common mullein
• B. Musk thistle
• C. Western salsify
• D. All of the above

Answer: (D)

Biennial broadleaf weeds complete their life cycle in two years: they form a rosette in the first year and then flower and set seeds in the second year. Common mullein starts as a fuzzy rosette and, in its second year, sends up a tall, woolly flowering stalk. Musk thistle follows the same two-year pattern, beginning as a rosette with spiny leaves and then producing a tall flowering stem with purple flower heads in the second year. Western salsify also behaves as a biennial: it overwinters as a rosette and then sends up a tall flowering stalk with yellow composite flowers.

Because each of these plants fits the two-year life cycle and is a broadleaf weed, all of the above are correct examples of biennial broadleaf weeds.