1. Acer rubrum   maple   spruce   ash   birch   Hint Half-n-half Clue   2. Juglans nigra   walnut   hickory   spruce   pine   Half-n-half Clue   3. Hibiscus lasiocarpus   birch   hibiscus   cedar   spruce   Half-n-half Clue   4. Picea pungens   spruce   cedar   sycamore   birch   Half-n-half Clue   5. Quercus velutina   pine   oak   sycamore   ash   Half-n-half Clue   6. Pinus aristata   oak   maple   birch   pine   Half-n-half Clue   7. Platanus occidentalis   oak   sycamore   birch   ash   Half-n-half Clue