Directory       News       Site Map       Home
    Jepson eFlora: Taxon page
Key to families | Table of families and genera

Previous taxon Indexes to all accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Previous taxon


Robert Lee Allen

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.
1 genus, ± 8 species: northern temperate; some cultivated for ornamental, shade; wood generally of limited commercial value. [Feng et al. 2005 Syst Bot 30:786–799] —Scientific Editor: Thomas J. Rosatti.
Unabridged 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.

(Greek: probably broad, for leaves) Fruit length excludes style.

Key to Platanus

P. ×hispanica Münchh. LONDON PLANE TREE
Stem: 12–24(36) m, erect; base generally <<= 0.5 m wide; outer bark light gray, inner green-cream. Leaf: stipules (0)1–2 cm, generally deciduous by maturity; petiole 2–10 cm; blade ± 11–18 cm, ± round or elliptic, ± glabrous. Staminate flower: calyx reduced, cup-like; petals free. Pistillate flower: calyx reduced, cup-like. Fruit: head 2.5–3.5 cm, generally sessile; achene 7.5–11 mm, top truncate, basal hairs 1/2–2/3 fruit length, persistent on fruit, head; style deciduous.
In cultivation, may persist from old homesteads, escapes to waterways; 16–155 m. Cascade Range Foothills, n Sierra Nevada Foothills, Sacramento Valley; possibly escapes cultivation in northern and eastern United States. [Platanus ×acerifolia (Aiton) Willd.; Platanus hispanica Ten.; Platanus ×hybrida Brot.] Stable hybrid between Platanus occidentalis L. and Platanus orientalis L., or possibly a non-hybrid cultivar of the latter.
Unabridged note: Evidently originated in 17th century, generally considered to be stable hybrid between Platanus occidentalis L. and Platanus orientalis L., thought by some to be non-hybrid cultivar of Platanus orientalis; for the former, Platanus ×hispanica Münchh. (1770) has priority over Platanus ×acerifolia (Aiton) Willd. (1805). Susceptible to sycamore scale insects, ± to sycamore anthracnose fungus. Backcrosses to parent species (or crosses with those species) common, variable, resistant to fungi. Hybrids with Platanus racemosa known from Cascade Range Foothills, Sacramento Valley, Peninsular Ranges (Orange Co.), suspected elsewhere, with leaves variously toothed, often hairy, heads generally 2–3; other authorities treat Platanus ×hybrida Brot. as the correct name, with Platanus ×acerifolia and Platanus ×hispanica as synonyms. Expanded author citation: Platanus ×hispanica Mill. ex Münchh.
Mar–May [Online Interchange]

Previous taxon: Platanus
Next taxon: Platanus racemosa


Name search

Citation for the whole project: Jepson Flora Project (eds.) 2013. Jepson eFlora,, accessed on Nov 29 2015
Citation for this treatment: [Author of taxon treatment] 2013. Platanus, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on Nov 29 2015

Copyright © 2014 Regents of the University of California
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.

Geographic subdivisions indicated for the distribution of Platanus X hispanica Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
View all CCH records


CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.