Jepson eFlora
Key to families | Table of families and genera

Key to Acer

View taxon page for Acer

(For a list of species in Acer, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Leaf compound, leaflets stalked; inflorescence axillary, pendent panicle ..... A. negundo

1' Leaf simple, palmately lobed, or compound with leaflets sessile; inflorescence not a pendent panicle

2. Abaxial leaf surface white or ± white-green; flowers present before leaves, in dense clusters; petals 0 ..... A. saccharinum

2' Abaxial leaf surface green; flowers present with leaves, inflorescence cyme, raceme, or panicle; petals present

3. Leaf lobes 7–9 ..... A. circinatum

3' Leaf lobes 3–5

4. Leaf 10–25 cm wide; inflorescence pendent, flowers 20–90 ..... A. macrophyllum

4' Leaf 1.4–10 cm wide; inflorescence ascending, flowers 2–30

5. At least leaf veins, margins pubescent; each lobe with 0–1(2), large, rounded teeth per side; fruit wings widely spreading 160–200° ..... [A. campestre]

5' Leaf glabrous; each lobe with 3–many, small, sharp teeth per side; fruit wings overlapping or spreading (40)70–120° ..... A. glabrum

6. Petiole 0.9–2.4 cm, blade 1.4–2.8 cm, 2–3.5 cm wide; lobes rounded or obtuse, lateral lobes with 3–7 obtuse to acute teeth on outer side ..... var. diffusum

6' Petiole 2.8–9.7 cm, blade 2.9–5.6 cm, 3.6–6.3 cm wide; lobes acute, lateral lobes with 5–22 acute to apiculate teeth on outer side ..... var. glabrum


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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