Bark furrowed. Buds usually large, very viscid, with a strongly balsamic odor. Leaves of long shoots and short branchlets variously shaped; petiole terete or subquadrangular, of varying length, sulcate; leaf blade abaxially usually white, adaxially green, base cuneate or rounded to shallowly cordate, without translucent margin. Bracts not fringed. Male flower: stamens 8--60; anthers long elliptic to globose. Female flower: disc usually entire, persistent; style short or absent; stigma 2--4-lobed. Capsule 2--4(or 5)-valved.