Alnus alnobetula subsp. fruticosa

(Ruprecht) Raus

Willdenowia 41: 129. 2011.

Common names: Siberian alder
Basionym: Alnus fruticosa Ruprecht Distr. Crypt. Vasc. Ross., 53. 1845
Synonyms: Alnus viridis subsp. fruticosa (Ruprecht) Nyman Alnus viridis var. fruticosa (Ruprecht) Regel
Treatment appears in FNA Volume 3.

Shrubs, spreading, to 3(–6) m. Bark gray-brown; lenticels pale. Leaf blade dark green, broadly ovate, 5–8(–10) × 3–6(–7) cm, base rounded to nearly truncate or nearly cordate, margins flat, sharply and densely doubly serrate, apex acute to short-acuminate; surfaces abaxially glabrous to sparsely pubescent, especially on veins, moderately to heavily resin-coated. Inflorescences: staminate catkins 3.5–6 cm. Infructescences 1.2–2 × 0.5–1.2 cm; peduncles 1–3 cm. 2n = 28.

Phenology: Flowering spring.
Habitat: Rocky or sandy coasts, stream banks, lakeshores, and damp, open areas
Elevation: 0–500 m


V3 506-distribution-map.gif

Alta., B.C., N.W.T., Sask., Yukon, Alaska, Calif., Oreg., Wash., n Asia.


This primarily subarctic Asian subspecies has long been mistaken in western North America for Alnus alnobetula subsp. crispa, which it closely resembles, or for subsp. sinuata (J. J. Furlow 1983b). It can be separated from the former by its larger and more coarsely toothed leaves, and from the latter by its much thicker, mostly single-toothed leaf blades.

Selected References


Lower Taxa

John J. Furlow +
(Ruprecht) Raus +
Alnus fruticosa +
Siberian alder +
Alta. +, B.C. +, N.W.T. +, Sask. +, Yukon +, Alaska +, Calif. +, Oreg. +, Wash. +  and n Asia. +
0–500 m +
Rocky or sandy coasts, stream banks, lakeshores, and damp, open areas +
Flowering spring. +
Wildenowia, +
Alnus viridis subsp. fruticosa +  and Alnus viridis var. fruticosa +
Alnus alnobetula subsp. fruticosa +
Alnus alnobetula +
subspecies +