| TREATMENT FROM THE JEPSON MANUAL (1993) |
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Jepson Interchange (more information) |
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©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora. |
AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY |
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]
Etymology: (Greek: probably broad, from leaves)