Jepson eFlora: Taxon page
Vascular Plants of California
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Ulmus americana

Higher Taxonomy
Family: UlmaceaeView Description 
Common Name: ELM FAMILY
Habit: Tree. Leaf: simple, alternate, 2-ranked; veins pinnate; stipules deciduous. Flower: radial; sepals 4--9, free to fused; corolla 0; stamens 4--9, opposite sepals; ovary superior, chamber 1, ovule 1, style branches 2. Fruit: 2-winged nutlet.
Genera In Family: 7 genera, +- 60 species: temperate to tropics; some cultivated for ornamental (Ulmus, Zelkova), used for wood (especially Ulmus). Note: Celtis moved to Cannabaceae.
eFlora Treatment Author: Alan T. Whittemore
Scientific Editor: Bruce G. Baldwin.
Genus: UlmusView DescriptionDichotomous Key

Common Name: ELM
Habit: Deciduous. Leaf: serrate (or doubly so), base generally oblique, 2° veins straight, parallel, extending to margin, each ending in a tooth; axils of 2° veins generally with prominent tufts of hairs. Inflorescence: umbels or short racemes in leaf axils on old wood; flowers sessile or pedicels 7--17 mm. Flower: bisexual; calyx generally bell-shaped, lobes 4--9; stamens 4--9, exserted; ovary strongly compressed; style divided to base, branches spreading.
Species In Genus: +- 40 species: northern temperate. Note: Widely cultivated as street trees; flowers, fruit needed for identification.
Ulmus americana L.
Habit: To 35 m; bark split into ridges that mostly curve together at their ends. Stem: corky outgrowths on branches 0; winter buds red-brown, conical or narrowly ovoid, +- pubescent. Leaf: 8.6--12.5 cm, 4.2--7 cm wide, elliptical or occasionally oblong, acuminate, generally slenderly so, margins strongly double-serrate, abaxial surface sparsely long-hairy on blade and veins, hairs tufted in vein axils. Inflorescence: flower, fruit before leaves in spring; pedicel 7--17 mm, slender. Fruit: 0.9--1.3 cm, 0.6--0.8 cm wide, elliptical or oblong, tan, margins densely ciliate, surfaces glabrous.
Ecology: Seeding along disturbed streambanks, or spreading by root suckers near old plantings; Elevation: 60--700 m. Bioregional Distribution: ScV, SCo; Distribution Outside California: native to eastern United States. Flowering Time: Feb--Mar
Jepson eFlora Author: Alan T. Whittemore
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Citation for this treatment: Alan T. Whittemore 2012, Ulmus americana, in Jepson Flora Project (eds.) Jepson eFlora, /eflora/eflora_display.php?tid=47473, accessed on October 26, 2020.

Citation for the whole project: Jepson Flora Project (eds.) 2020, Jepson eFlora,, accessed on October 26, 2020.

Ulmus americana
click for enlargement
© 2016 Keir Morse
Ulmus americana
click for enlargement
© 2016 Keir Morse
Ulmus americana
click for enlargement
© 2016 Keir Morse
Ulmus americana
click for enlargement
© 2016 Keir Morse
Ulmus americana
click for enlargement
© 2016 Keir Morse
Ulmus americana
click for enlargement
© 2016 Keir Morse

More photos of Ulmus americana in CalPhotos

Geographic subdivisions for Ulmus americana:
ScV, SCo
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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
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).