SelecTree: Tree Detail
Photo Locations: Huntington Botanical Gardens - San Marino, CA, Foster Botanical Gardens - Honolulu, HI, Tropical Gardens of Maui - HI, Hilo, HI and Lyon Arboretum - Honolulu, HI
A widely grown palm that is extensively naturalized in wet and moderately wet lower elevation areas, especially along the Hamakua Coast north of Hilo. Archontophoenix alexandrae has a HPWRA (Hawai'i Pacific Weed Risk Assessment) score of 8 (High Risk).
Native to Northeastern Australia.
Additional Common Names
ALEXANDRA PALM, ALEXANDER PALM, KING PALM, STEP PALM
Erect and requires ample growing space.
Has Evergreen foliage.
Height: 50 - 80 feet.
Width: 10 - 15 feet.
Growth Rate: 24 Inches per Year.
Longevity 50 to 150 years.
Leaves Pinnately Compound, Green, No Change, Evergreen.
Flowers Inconspicuous. Pink or Purple.. Has separate male and female reproductive parts on the same tree (monoecious).
Red Drupe, Small (0.25 - 0.50 inches).
Bark Dark Gray or Light Gray, Smooth.
Shading Capacity Rated as Moderate in Leaf.
Litter Issue is Wet Fruit and Leaves.
Tree Site Conditions & Constraints
Sunset Zones 21 - 24; H1, H2.
USDA Hardiness Zones 10 - 11.
Exposure Full Sun to Partial Shade.
Loam or Sand Texture.
Highly Acidic to Highly Alkaline Soil pH.
Seaside Tolerance is Good in South Coast.
Pests & Disease Information
Resistant to Texas Root Rot.
Health, Safety & Environmental Concerns
Branch Strength Rated as Medium.
Root Damage Potential Rated as Moderate.
None Known Health Hazard.
Cite this tree:
SelecTree. "Archontophoenix alexandrae Tree Record." 1995-2020. Sep 29, 2020.
< https://selectree.calpoly.edu/tree-detail/archontophoenix-alexandrae >