Related Clues:

• Stately shaders
• Nursery items
• They may be slippery
• See 4-Down
• Plain lack
• Classic street liners
• 'Desire Under the ___'
• Shade trees
• Arbor Day honorees
• 'The moan of doves in immemorial ___': Tennyson
• Walnuts and others
• Corners
• They're for the birds
• Boulevard border, perhaps
• They line some old streets