Which plant is a biennial with yellow flowers grouped in a corn cob shape?

• A. Larkspur
• B. Common Mullein
• C. Showy Milkweed
• D. Downy Brome

Answer: (B)

The key idea is a biennial plant that produces a tall, dense flowering spike with yellow blooms. Common mullein grows as a rosette in its first year, then sends up a tall, unbranched stalk in the second year crowded with yellow flowers along the spike, giving a candle- or corn-cob–like appearance. That combination—the biennial habit plus a tightly packed yellow spike—best fits common mullein. The other options don’t match this specific look: larkspur flowers are often blue or purple on a spire, not dense yellow spikes; showy milkweed has pinkish flowers arranged in umbels; downy brome is a grass with seed heads, not a yellow corn-cob spike.