foliage

The collective leaves of a plant or tree — the green mass, the canopy’s fabric, the photosynthetic surface area of a living thing. Foliage is what makes a forest a forest rather than a collection of poles. In autumn, the word becomes charged: fall foliage, the annual spectacle of chlorophyll withdrawing and the underlying pigments — carotenoid yellows, anthocyanin reds — being revealed.