Walnut Tree Species

Members of the Genus Juglans

By Vanessa Richins Myers

Updated 01/23/18

The Latin name for the walnut tree genus is Juglans, which translates to "Jupiter's nut." They belong to the Juglandaceae family, which also includes hickories and pecans (Carya spp.). Walnut trees are monoecious, meaning a single tree contains both male (catkin) and female (pistillate) flowers, allowing them to self-pollinate. However, nut production is best when walnut trees of different cultivars are planted in groups, as is typically done in walnut groves cultivated for nut production.

When choosing a walnut tree for planting on your property, look closely at the recommended USDA Zones as well as the tree height and normal exposure type. Also, it's important to choose the plants around your walnut trees carefully. This genus produces a toxin called juglone that can be harmful to the plants around it in varying degrees, through an effect known as allelopathy. Make sure any surrounding plants you're considering are not prone to juglone toxicity.

  • 01 of 11

    Andean Walnut

    Nogal en Fragen
    horrabin/Flickr/CC BY 2.0
    • Latin Name: Juglans neotropica
    • Other Common Names: Tropical walnut, Colombian walnut, nogal, Ecuadorian walnut, nogal Bogotano
    • Native to: Colombia, Ecuador, and Peru
    • USDA Zones: Likely 10–11
    • Height: Up to 100 feet
    • Exposure: Full to partial sun; cannot grow in shade
  • 02 of 11

    Arizona Black Walnut

    Juglans major (Arizona Walnut). Morton Arboretum acc. 614-47*1. 52 years old at this photo, grown from seed.
    Bruce Marlin/Wikimedia Commons/CC 3.0
    • Latin Name: Juglans major
    • Other Common Names: Arizona walnut, nogal, New Mexico walnut, mountain walnut, River walnut, nogal silvestre
    • Native to: Arizona, New Mexico, Oklahoma, Texas, Utah
    • USDA Zones: 6–10
    • Height: Up to 50 feet
    • Exposure: Full sun to part shade
  • 03 of 11

    Black Walnut

    Black Walnut nut and leave detail
    MONGO/Wikimedia Commons/Public Domain
    • Latin Name: Juglans nigra
    • Other Common Names: Eastern black walnut, American walnut
    • Native to: North America
    • USDA Zones: 4–9
    • Height: 50–120 feet
    • Exposure: Full sun
  • 04 of 11

    Brazilian Walnut

    Walnut-tree 20041012 2599
    George Slickers/Wikimedia Commons/Creative Commons 2.5
    • Latin Name: Juglans australis
    • Other Common Names: Nogal criollo, tropical walnut
    • Native to: Argentina and Bolivia
    • USDA Zones: Unknown
    • Height: Up to 82 feet
    • Exposure: Likely full sun
    Continue to 5 of 11 below.
  • 05 of 11

    Butternut

    A butternut
    Modal jig/Wikimedia Commons/CC 3.0
    • Latin Name: Juglans cinerea
    • Other Common Names: Oilnut, white walnut, long walnut
    • Native to: Eastern North America
    • USDA Zones: 3–7
    • Height: 40–60 feet
    • Exposure: Full sun
  • 06 of 11

    California Black Walnut

    California Black Walnut in Puente Hills.
    Animalparty/Wikimedia Commons/CC 2.5
    • Latin Name: Juglans californica
    • Other Common Names: Southern California black walnut, California walnut, Southern California walnut
    • Native to: California
    • USDA Zones: 8–10
    • Height: 15–40 feet
    • Exposure: Full sun
  • 07 of 11

    English Walnut

    noyer centenaire en automne (Juglans regia)
    Thesupermat/Wikimedia Commons/CC BY S.A. 3.0
    • Latin Name: Juglans regia
    • Other Common Names: Persian walnut, common walnut, Carpathian walnut
    • Native to: Europe and Asia
    • USDA Zones: 5–9
    • Height: 65–115 feet
    • Exposure: Full sun
  • 08 of 11

    Hinds' Black Walnut

    California Black Walnut in Puente Hills.
    Animalparty/Wikimedia Commons/CC 2.5
    • Latin Name: Juglans hindsii. Some put this as a variety of Juglans californica.
    • Other Common Names: Northern California walnut
    • Native to: California
    • USDA Zones: 7–10
    • Height: 30–60 feet
    • Exposure: Full sun
    Continue to 9 of 11 below.
  • 09 of 11

    Japanese Walnut

    Heartnut (Juglans ailantifolia) in flower
    Tahirs/Wikimedia Commons/CC 1.0
    • Latin Name: Juglans ailantifolia
    • Other Common Names: Heartnut, which is specifically Juglans ailantifolia var. cordiformis, though some set it as its own species (Juglans cordiformis). Siebold walnut is another possible common name for the Japanese walnut.
    • Native to: Japan
    • USDA Zones: 4–7
    • Height: Usually 40–65 feet
    • Exposure: Full sun
  • 10 of 11

    Manchurian Walnut

    Manchurian Walnut
    Jean-Pol GRANDMONT/Wikimedia Commons/CC BY 2.5
    • Latin Name: Juglans mandshurica
    • Other Common Names: Chinese walnut
    • Native to: China, North Korea, South Korea, and Russian Far East
    • Height: Up to 82 feet
    • Exposure: Full sun
  • 11 of 11

    Texas Black Walnut

    Texas black walnut
    Jerry Friedman/Wikimedia Commons/CC BY 2.0
    • Latin Name: Juglans microcarpa. It may also be known as Juglans rupestris or Juglans nana.
    • Other Common Names: Texas walnut, little black walnut, nogalito, river walnut, little walnut, dwarf walnut, nogal, Mexican walnut
    • Native to: Kansas, New Mexico, Oklahoma, Texas
    • USDA Zones: Likely 5–7
    • Height: 15–50 feet
    • Exposure: Full sun to part shade