Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
1 Rays yellow
..2 Rays sterile and usually neutral; receptacle chaffy only toward the middle
....3 Achenes not tuberculate; leaves not glandular-punctate beneath
....3 Achenes tuberculate; leaves glandular-punctate beneath