Rosettes have large, wooly, blue-green leaves that are aromatic when crushed?

• A. Mediterranean Sage
• B. Spotted Knapweed
• C. Russian Knapweed
• D. Leafy Spurge

Answer: (A)

The key idea is using a combination of leaf texture, color, and scent to identify a weed in its rosette stage. Mediterranean sage forms basal rosettes with large, woolly, blue-green leaves. The dense hairs and the waxy blue-green color are adaptations to dry conditions, and when you crush the leaves, they release a distinctive aromatic sage scent from the essential oils in the foliage. This scent is a reliable clue that you’re looking at a sage, not the knapweeds or leafy spurge, whose leaves are not woolly blue-green and do not produce that sage-like aroma.