Related Clues:

• Rock cover
• Plankton component
• Matlike growth
• Terrarium growth
• Chlorophyllous plant
• Rolling stone's lack
• Aquatic plant
• Tufted plant
• Pond floater
• Pond scum component
• It lacks roots
• Lowlife?
• Sign of disuse
• Pond scum
• Oakmoss, e.g.