White Alder

Alnus rhombifolia

White Alder

US NPS Santa Monica Mountains National Recreation Area [2]

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Betulaceae
Genus:
Alnus
Species:
Alnus rhombifolia

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Tree
Height:
More than 40 ft
Light Requirements:
Part Shade
Drought Tolerance:
High
Bloom Months:
sep, oct, nov
Bloom Colors:
Green

Native Range

United States: California, Idaho, Montana, Nevada, Oregon, Washington

Keystone Species Ranking

Caterpillar Keystone:
★☆☆☆☆ Based on number of butterfly and moth species using this genus as host plant (Source: National Wildlife Federation)

Host Plant for Caterpillars

Cleahtrea nola moth (Nola clethrae), Large Red-belted Clearwing (Synanthedon culiciformis), Phyllonorycter incanella, Western Tiger Swallowtail (Papilio rutulus)

Soil Requirements

Soil Type:
moist, well-drained loamy soil
pH:
5.5 - 7.5 (slightly acidic to neutral)
Drainage:
tolerates poor drainage
Moisture:
consistently moist
Notes:
Commonly found along streams and rivers

Germination Information

Pre-treatment: Seeds are soaked in a 1% hydrogen peroxide solution for 24 hours, rinsed, and then soaked in water for an additional 24 hours. Seeds are then sown into trays filled with stabilized medium plugs and placed in refrigeration at 1 to 3 °C for 20 days. Trays are checked weekly for moisture and mold.

Establishment: The plant is native to western North America and prefers moist soils or areas near permanent water sources. It is tolerant of part shade, full sun, sand, and clay.

Source: npn.rngr.net