Related Clues:

• Former U.S. mil. acronym
• Madrone or magnolia
• Pollen case
• Pro --
• Genealogical diagram
• Bomber plane org. from 1946 to 1992
• Oak or pine
• It has bark but no bite
• Cul-de- --
• Hierarchical chart
• Squirrels' hangout
• Swing support, perhaps
• Pro ___ (proportionally)
• It's stuffed with wood
• Cherry or chestnut