Juglans major (Torr.) A. Heller
Arizona Walnut, Arizona Black Walnut, River Walnut, Mountain Walnut, Nogal Silvestre
Juglandaceae (Walnut Family)
Synonym(s): Juglans elaeopyren, Juglans microcarpa var. major, Juglans rupestris var. major
USDA Symbol: juma
Arizona walnut is a round-crowned deciduous tree to 48 ft. in height. With furrowed bark on the trunk, gray twigs, and reddish brown new growth covered with hairs visible under a 10x hand lens. Leaves up to foot long with 4 to 8 pairs of leaflets along a central axis and a single leaflet at the tip the margins finely toothed and the midrib of the lateral leaflet off-center, the wider part of the blade toward the leaf tip. Flowers inconspicuous, in elongate green clusters. Fruit spherical, 1 to 1 1/2 inches in diameter, intermediate in size between Black Walnut (Juglans nigra) and Little Walnut (Juglans microcarpa).
The small walnuts, known in Spanish as nogales, are gathered locally. The wood, like that of Black Walnut, is used for furniture and gunstocks, but the supply is limited. The valuable enlarged burls and bases of the trunks make beautifully patterned tabletops and veneer.
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Leaf Retention: Deciduous
Leaf Complexity: Pinnate
Breeding System: Flowers Unisexual , Monoecious
Fruit Type: Nut
Size Notes: 36-48 feet tall.
Bloom InformationBloom Color: Green , Brown
Bloom Time: Apr , May
DistributionUSA: AZ , NM , OK , TX , UT
Native Distribution: C. TX to c. AZ & mts. of Mex. south to Chiapas
Native Habitat: Dry stream banks; canyons; 3500 to 7000 ft.
Growing ConditionsWater Use: Medium
Light Requirement: Sun , Part Shade
Soil Moisture: Dry
CaCO3 Tolerance: Low
Cold Tolerant: yes
Heat Tolerant: yes
Soil Description: Dry, rocky soils.
Conditions Comments: Arizona walnut is a round-crowned deciduous tree. It often has a forked trunk and rounded crown of widely spreading branches, distinct walnut odor. Bark is dark and deeply furrowed and ridged. Branched are wide-spreading. Leaves are pinnate. The thick-shelled, edible nut is about 1 in. in diameter.
BenefitUse Wildlife: The nuts provide food for wildlife.
Interesting Foliage: yes
PropagationPropagation Material: Seeds
Description: Plant nuts in fall or spring. If nuts are sown in spring, they must be stratified.
Seed Collection: Collect nuts in fall or winter when husks begin to turn black and split open. Remove husks. It is not necessary to remove shell. Sow immediately or keep in moist sand over winter. Nuts lose viability if allowed to dry out.
Seed Treatment: Stratify for 60-120 days at 34-41 degrees.
Commercially Avail: yes
National Wetland Indicator Status
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Lady Bird Johnson Wildflower Center - Austin, TX
Brackenridge Field Laboratory - Austin, TX
NPSOT - Austin Chapter - Austin, TX
NPSOT - Williamson County Chapter - Georgetown, TX
BibliographyBibref 298 - Field Guide to Texas Trees (1999) Simpson, B.J.
Bibref 355 - Landscaping with Native Plants of Texas and the Southwest (1991) Miller, G. O.
Bibref 354 - Native & Naturalized Woody Plants of Austin & the Hill Country (1981) Lynch, D.
Search More Titles in Bibliography
Web ReferenceWebref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter
Additional resourcesUSDA: Find Juglans major in USDA Plants
FNA: Find Juglans major in the Flora of North America (if available)
Google: Search Google for Juglans major
MetadataRecord Modified: 2023-04-06
Research By: TWC Staff