Answer:

green

Answer	Crossword Clue
GREEN	Like most vegetation
GREEN	Environmentally conscious
GREEN	Easiest rating for a ski slope

GREEN	See 100-Across
GREEN	See 28-Down
GREEN	Inexperienced
GREEN	Eco-conscious
GREEN	Concerned about the environment
GREEN	Eco-friendly
GREEN	Like the starts of the answers to the six starred clues
GREEN	Place for a hole

GREEN	European liberal
GREEN	Sinking area?
GREEN	Verdant
GREEN	In leaf
GREEN	White House's ... Room
GREEN	Village center
GREEN	Golf hole's locale
GREEN	Unseasoned

GREEN	Untrained
GREEN	Environmentally-minded