Which plant has star-like flowers with five petals with black dots on the margins and occurs in clusters at the ends of stems?

• A. Larkspur
• B. St. John's Wort
• C. Poison Hemlock
• D. Common Mullein

Answer: (B)

Flower shape and where the blooms appear are strong clues for identifying plants in the field. St. John’s Wort has small yellow flowers with five petals that come together to form a star-like shape. A key detail is the tiny black dots or glands along the margins of the petals, which are especially noticeable when you inspect the blooms. These flowers tend to cluster at the ends of stems, giving a terminal, compact look.

This combination—five-petaled star-shaped yellow flowers with black margin glands, in clusters at the ends of stems—fits St. John’s Wort. Other plants listed have different flower forms and arrangements: larkspur shows spurred, intricate flowers; poison hemlock has white umbrella-like flower clusters; common mullein features a tall spike of yellow flowers rather than terminal clusters with star-shaped petals.