A Three-Leaf (but Not a Four-Leaf) Clover
Puzzle 13 of Anthropology Hard Pack
Question is: A Three-Leaf (but Not a Four-Leaf) Clover
and the answer is: SHAMROCK
Word Meaning:
SHAMROCK — The trefoil leaf of any small clover, especially Trifolium repens, or such a leaf from a clover-like plant, commonly used as a symbol of Ireland.
Definitions from Wiktionary.