Related Clues:

• Rock cover
• Matlike growth
• Terrarium growth
• Rolling stone's lack
• Tufted plant
• Sign of disuse
• Richard's 'On Your Toes' collaborator
• Sphagnum, for one
• Forest undergrowth
• Rootless plant
• Richard's 'Manhattan' collaborator
• Rock growth
• Bryophyte
• Spore-producing plant
• Richard's longtime partner on Broadway