Possible Clues:

• The flowers in Amy Lowell's 'Your great puffs of flowers / Are everywhere in this my New England'
• Fragrant flowering shrubs
• 'We'll gather ... in the spring' (Ivor Novello song)
• New Hampshire state flowers
• Fragrant shrubs
• Flowers that 'in the dooryard bloom'd,' in a Whitman poem
• Whitman's ''dooryard'' blooms
• Fragrant purple blooms
• Title flora in a Whitman poem
• Aromatic signs of spring