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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.


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.
± 40 species: northern temperate. Widely cultivated as street trees; flowers, fruit needed for identification.

Key to Ulmus

1. Leaf 1–3.5 cm wide, obtuse, acute, or short-acuminate, margin simply or occasionally doubly serrate

2. Bark not furrowed, peeling as irregular woody scales 2–8 cm wide, orange-brown where freshly exposed, soon weathering ash-gray; flowers, fruit in autumn ..... U. parvifolia

2' Bark deeply furrowed, remaining firmly attached, medium gray; flowers, fruit appearing before leaves in spring ..... U. pumila

1' Leaf 3.5–8.3 cm wide, acuminate, margin doubly serrate

3. Pedicel 7–17 mm, slender; flower, fruit drooping; fruit wing margin densely ciliate; bark split into ridges that mostly curve together at their ends; branches never with corky outgrowths ..... [U. americana]

3' Flower, fruit sessile or nearly so; fruit including wings glabrous except for pubescence on stigmatic surface in notch; bark split into ridges or plates that seldom curve together; generally some branches with corky warts or wings ..... [U. minor]


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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