Alnus rubra
Common name
red alder
Family
Betulaceae
Flora category
Vascular – Exotic
Structural class
Trees & Shrubs - Dicotyledons
Conservation status
Not applicable
Brief description
Deciduous tree 26–30 m tall; leaves 760–152 × 25–38 mm, coriaceous; adaxially glabrous, dark green, abaxially pale covered in fine rust-red pubescence; lamina pinnately veined (orange-reddish veins), obtuse to elliptic, base obtuse to rounded, apex acute; margins finely doubly serrate (teeth gland-tipped), sometimes revolute.
Habitat
Moist disturbed sites
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Detailed description
Deciduous tree 26–30 m tall, 0.3–1.2 m diam. Trunk clean with a straight bole, usually devoid of branches for one third to half of length; crown narrowly pyramidal or dome-shaped and rounded; branches ± pendulous. Bark ash-grey to grey-brown, generally smooth but breaking with age into flat, irregular plates near the base; inner bark initially tan but turning red when exposed to air. Buds distinctly stalked. Leaves 760–152 × 25–38 mm, coriaceous, adaxially glabrous, dark green; abaxially pale covered in fine rust-red pubescence; lamina pinnately veined, obtuse to elliptic, base obtuse to rounded, apex acute, margins finely doubly serrate (teeth gland-tipped), sometimes revolute.
Flower colours
Green
Year naturalised
1990.
Origin
Western North America
Reason for introduction
Timber tree
Etymology
alnus: From an old Latin name for alder
rubra: Red
Attribution
Ecroyd CE. Rotorua Botanical Society Newsletter 52: 29-32 (2009)