TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

PLATANACEAE

PLANE TREE, SYCAMORE FAMILY

Elizabeth McClintock

Tree, generally monoecious, wind-pollinated
Stem: branches irregular below, spreading to erect above; bark irregularly colored, scale-like, peeling; twigs dense-hairy
Leaves simple, alternate, deciduous, generally palmately 3- or 5-lobed, -veined; stipules generally leaf-like, free or fused around stem, shed before leaves; petiole at base dilated, hollow, ± covering bud; blade dense-hairy, glabrous in age, hairs stellate
Inflorescence: heads 1–6, ± 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
Flowers unisexual; calyx cup-shaped, scale-like, entire or 3–6(8)-lobed or sepals ± free
Staminate flower: petals 3–6, fleshy or scale-like, minute or vestigial; stamens 3–6(8), alternate petals, anthers subsessile, axis above anther expanded, disk-like; pistils vestigial
Pistillate flower: petals 3–6, minute, or generally 0; staminodes often 3–4; pistils (3)5–9, ovaries superior, 1-chambered, generally 1-ovuled, style 1
Fruit: spheric head of small, hairy, basally bristly achenes; style persistent
Genera in family: 1 genus, ± 8 species: n temp; some ornamental, especially P. X acerifolia (Aiton) Willd., London plane tree; some cultivated for wood, veneer
Reference: [Ernst 1963 J Arnold Arbor 44: 206–210]