Jepson eFlora: Key page
Vascular Plants of California
Key to families | Table of families and genera

Key to Alnus

View taxon page for Alnus

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

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

1. Tree, > 9 m, not forming thickets

2. Leaf  adaxially shiny, base  to  ..... [A. cordata]

2' Leaf blade adaxially dull, base rounded to 

3. Leaf margin generally , not tightly rolled under ..... A. rhombifolia

3' Leaf margin doubly serrate, tightly rolled under ..... A. rubra

1' Shrub, < 9 m, forming thickets

4. Lateral  stalked, scales 0;  < cone-like  thick, margin doubly serrate to teeth pointed, blunt, or rounded ..... A. incana subsp. tenuifolia

4' Lateral buds , scales present; pedicels > cone-like catkins; leaf thin to firm, margin serrate, teeth pointed ..... A. viridis

5. Blade firm, adaxially dark green, margins generally densely serrate; coastal, 0–500 m ..... subsp. fruticosa

5' Blade thin, adaxially yellow-green, margins coarsely doubly serrate; montane, 1000–2700 m ..... subsp. sinuata


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Citation for the whole project: Jepson Flora Project (eds.) . Jepson eFlora, [accessed on ]

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

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