Related Clues:

• Pond greenery
• Tiny aquatic plant
• Pond dweller
• Nonflowering plant
• Sargassum, e.g.
• Simple water dweller
• Marine growth
• It creates energy through photosynthesis
• Surface residue
• Fruit of the oak
• Rootless plant
• Seaweed and kelp, e.g.
• Bit of pond scum
• Birdbath greenery?
• Chlorophyllous organism