Habit: monoecious trees with irregularly plated and flaking bark
Leaves***: alternate, simple and ***palmately lobed, stipulate and stipules often united around twig; covered with branched hairs
Inflorescence***: spherical heads
Flowers: imperfect, regular
Sepals: 3-4, distinct
Petals: 3-4, minute; absent in females fls.
Stamens: 3-4, opposite the sepalsconnate by connectives
Gynoecium: apocarpous of 5-8 carpels; ovaries superior with 1 locule and 1-2 apical ovules
Fruit: dense head of achenes with long bristles
Diversity: 1 genus / 6-7 species
Distribution: mostly north temperate
Economics: Sycamores are important trees of the riparian community; the branched hairs from leaves and fruit can cause bronchial problems in sensitive people