Alnus alnobetula subsp. fruticosa
A circumboreal, deciduous shrub or small tree in Betulaceae that rapidly colonizes moist disturbed sites, fixes atmospheric nitrogen, forms dense thickets, grows 1–5 m tall, bears broadly ovate leaves with densely doubly serrate margins and winter catkins, and is distributed from Alaska to California in North America and into Russia and Mongolia to western Canada
Common Names
Green Alder, Mountain Alder, Siberian Alder, Siberian Green Alder, Sitka Alder
Summary
Siberian Alder is a vigorous deciduous shrub or small tree with a spreading to compact habit, typically 1–3 m tall, native to circumboreal regions of Europe, Asia, and North America (including Alaska to California). Leaves are broadly ovate with densely doubly serrate margins, green above, and bark is smooth yellowish-brown to gray with lenticels; catkins are conspicuous in winter, and fruits are small nutlets with broad wings, forming dense thickets.
Preferring moist, open sites from low elevations to subalpine areas, it is common in moist woods, stream banks, bogs and fens and can occur on montane slopes; it coppices easily from stump or suckers and fixes atmospheric nitrogen via root nodules, making it useful for restoring disturbed woodlands and for erosion control.
Lifecycle
Perennial
Height
9.8-19.7 ft
Spread
9 ft 10 in – 19 ft 8 in
Hardiness Zones
Zones 3-8
Sunlight Requirements
Ideally full sun.
Soil Type
No single ideal; tolerates a wide range of soils, including moist loamy soils (well-draining yet moisture-retentive; pH around 6.5) and wet, rocky, sandy, or nutrient-poor soils.
Soil Drainage
Poorly drained, wet soils.
Soil pH
6.5-6.5, Slightly acidic to neutral
Bloom Time
Spring
Foliage Color
Green
Fall Foliage Color
Brownish
Leaf Lifecycle
Deciduous
Growth Rate
Fast
Seasons of Interest
Spring and Winter
Propagation Methods
Seeds and Cuttings
Attracts Wildlife
Attracts wind pollinators
Taxonomy
- Taxonomic Rank
- Subspecies
- Author
- (Rupr.) Raus
- Publication
- Willdenowia 41: 129 (2011)
Superior Taxa
- Kingdom
- Plantae
- Subkingdom
- Pteridobiotina
- Phylum
- Angiosperms
- Order
- Fagales
- Family
- Betulaceae
- Genus
- Alnus
- Species
- Alnus alnobetula
Synonyms
Alnaster fruticosus Alnus fruticosa subsp. montana Alnus viridis var. stenoptera Alnus crispa f. parvifolia Alnus fruticosa Alnus fruticosa f. arborescens Alnus maximowiczii var. parvifolia Duschekia fruticosa Alnus pumila Alnus tristis Alnus viridis Alnus viridis var. fernaldii Alnus viridis subsp. fruticosa Alnus viridis var. sibirica Alnus viridis var. communis Alnus fruticosa var. typica Alnus pumila Alnus fruticosa f. normalis Alnus viridis var. fruticosa Alnus alnobetula var. fruticosa Alnus fruticosa f. macrophylla Alnus fruticosa f. vulgaris Alnus orbiculata