Luxuriant means "growing abundantly," "flourishing vigorously": "The tropical foliage was luxuriant." Luxurious means "fond of, or given to, luxury": "These hotel rooms are luxurious." Approximate synonyms of luxurious are sensuous, voluptuous, sumptuous, self-indulgent, epicurean, and rich. Approximate synonyms of luxuriant are lush, teeming, fruitful, and prolific.
Dictionary of problem words and expressions. Harry Shaw. 1975.