Possible Clues:

• Subject of an annual festival in Holland, Mich
• Local fool blossoms before the summer holidays
• Flower that symbolizes paradise on earth
• Flowering bulb (from Amsterdam?)
• A bloomer injecting lithium into sheep
• I left upset ram without something it would eat?
• Flowering perennial
• It blooms in 11 down
• May bloom
• A white one is said to symbolize 'I'm sorry'