What is the common name for Antirrhinum?

The correct answer is Snapdragon, which is the common name for the genus Antirrhinum. This plant is well-known for its unique flower shape, which resembles a dragon's mouth that opens and closes when squeezed, hence the name "snap" dragon. Snapdragons are valued in gardens for their colorful, tubular flowers and their vertical growth habit, making them popular choices for borders and cut flower arrangements.

The other options refer to different types of plants: Petunias are part of the genus Petunia, marigolds belong to the genus Tagetes, and verbenas are part of the genus Verbena. Each of these has distinct characteristics and different botanical classifications, further emphasizing that Antirrhinum specifically corresponds to the common name Snapdragon.