Willow Identification Key: Leaves soon glabrous beneath Leaves soon glabrous beneath; yellow-green under bark Leaves often opposite, widest above middle Spreading or upright to 7 m tall. Leaves often opposite, widest above middle; bitter to taste Leaves always alternate, widest below middle Shoots 1-2 yr with white bloom, leaves glaucous beneath. Leaves always alternate, widest at or below middle; not bitter to taste