Common Name: PLANE-TREE or SYCAMORE FAMILY
Habit: Tree, generally monoecious, wind-pollinated; hairs many-branched. Stem: bark peeling in scaly plates, leaving +- smooth areas of various colors, in age dark, thick, fissured; twig hairs dense. Leaf: simple, alternate, deciduous; lobes, veins generally 3,5(7), palmate; stipules generally leaf-like, free or fused around stem, shed by leaf maturity or not; petiole at base dilated, hollow, +- covering bud; blade hairs dense, +- 0 in age. Inflorescence: heads 1--7, +- evenly spaced on axis, spheric, many-flowered, sessile or on pendent peduncles, generally unisexual; staminate breaking apart in age; pistillate persistent; bracts subtending heads, flowers. Flower: unisexual; calyx cup-shaped, sepals (0)3--6(8), free or united basally. Staminate Flower: petals 3--6, minute or vestigial, fleshy or scale-like; stamens 3--6(8), alternate petals, anthers subsessile, axis above anther expanded, disk-like, +- peltate; carpels vestigial or 0. Pistillate Flower: petals 3--6, minute, or generally 0; staminodes often 3--4; carpels (3)5--9, free, ovary of each superior, 1-chambered, generally 1-ovuled, with 1 +- linear style. Fruit: achenes in spheric head, small, each with hairs from base, shorter hairs up the side; style persistent, beak-like, or deciduous.
Genera In Family: 1 genus, +- 8 species: northern temperate; some cultivated for ornamental, shade; wood generally of limited commercial value, although long ago used for buttons, the trees then called buttonwood.
Unabridged Note: Leaves and twigs with many-branched hairs, each comprising a single multicellular central axis with unicellular lateral, generally whorled rays.
eFlora Treatment Author: Robert Lee Allen
Scientific Editor: Thomas J. Rosatti.