Little Walnut

Juglans microcarpa

Other common name(s):

Nogalito, Texas Walnut, Texas Black Walnut, River Walnut, Nogalillo, Namboca

Family:

Juglandaceae (Walnut Family)

Plant Ecoregion Distribution Map

This map uses data from the US EPA. EPA  servers have been offline frequently so maps may not display. We are working on a solution.

Chihuahuan Deserts, Edwards Plateau
Chihuahuan Basins and Playas, Chihuahuan Desert Grasslands, Chihuahuan Montane Woodlands, Low Mountains and Bajadas, Stockton Plateau
Balcones Canyonlands, Edwards Plateau Woodland, Llano Uplift, Semiarid Edwards Plateau
Northern Blackland Prairie

Plant Characteristics

Growth Form

Tree

Height

20
to
30
ft.

Spread

20
to
30
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Sand, Loam, Clay, Rocky, Limestone, Dry

Light Requirement

Sun, Part Shade

Water Requirement

Low, Medium

Native Habitat

Woodland

Bloom and Attraction

Bloom Color

White, Green

Bloom Season

Spring

Seasonal Interest

Fall Color, Nuts, Nectar, Pollen, Larval Host, Nesting Material

Wildlife Benefit

Butterflies, Birds, Small Mammals

Maintenance

Moderate to fast growth rate. Protect seedlings from browsers until established. Trees emit a chemical, called “juglones”, into the soil which prevent many other plants from growing nearby. Little walnut is an excellent woody plant for stabilizing sand and gravel bars in riparian areas. Drought-tolerant and native to the western half of Texas in scattered canyons. WARNING: flowers are poisonous. Propagation: seed.

Comments

Blooms March-June. Grows as a small tree or shrub. Its smooth or lightly furrowed branches form a broad, rounded crown. Compound leaves are long, narrow and yellow-green. Flowers grow on catkins. Trees do not bear fruit until 15-20 years of age. Nuts are the smallest of the Walnut species. Larval host: Banded Hairstreak Butterfly.

References

1) Griffith, Bryce, Omernick & Rodgers (2007). Ecoregions of Texas. 2) Miller, George O., Landscaping with Native Plants of Texas 2nd Ed., 2013, pg 48. 3) https://www.wildflower.org/plants/result.php?id_plant=JUMI. 4) https://portal.torcherbaria.org/portal/taxa/index.php?taxon=Juglans+microcarpa&formsubmit=Search+Terms. 5) http://bonap.net/TDC/Image/Map?taxonType=Species&taxonId=13102&locationType=County&mapType=No, 6) https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=19253#nullrmal. 7) Native and Adapted Landscape Plants, City of Austin and Texas A&M, 2014.
Material Treatment Method Collection References
Seed Stratification Stratify for 60-120 days at 34-41 degrees. Sow in spring. https://www.wildflower.org/plants/result.php?id_plant=JUMI
Seed No Treatment Remove husks. It is not necessary to remove shell. Sow immediately in fall Collect nuts in fall or winter when husks begin to turn black and split open. https://www.wildflower.org/plants/result.php?id_plant=JUMI

About the Region

Fall Symposium 2025 Logo - Teach for the Future

Salado, the location of our Fall 2025 Symposium, lies at the intersection of two ecoregions: the Edwards Plateau (Limestone Cut Plain) and Blackland Prairie (Northern Blackland Prairie).

The Edwards Plateau area is also called the Hill Country; however, this general term covers a much larger area extending farther north. Spring-fed creeks are found throughout the region; deep limestone canyons, rivers, and lakes (reservoirs) are common. Ashe juniper is perhaps the most common woody species found throughout the region. Additional woody species include various species of oak, with live oak (Quercus fusiformis) being the most common. Sycamores (Platanus occidentalis) and bald cypress (Taxodium distichum) border waterways. This area is well known for its spring wildflower displays, though they may be viewed in spring, late summer, and fall, as well. According to Texas Parks and Wildlife, average annual rainfall in the Edwards Plateau ranges from 15 to 34 inches.

The Blackland Prairie extends from the Red River south to San Antonio, bordered on the west by the Edwards Plateau and the Cross Timbers, and on the east by the Post Oak Savannah. Annual rainfall averages 30 to 40 inches, with higher averages to the east. This region is dominated by prairie species. The most common grass species include little bluestem (Schizachyrium scoparium) and Indian grass (Sorghastrum nutans) in the uplands and switchgrass (Panicum virgatum) in the riparian areas and drainages. Common herbaceous flowering plants include salvias, penstemons, and silphiums. This area has suffered greatly from overgrazing and agricultural use. Few intact areas remain, though many of the plants can be found along county roadsides throughout the region.

Our fall Symposium host chapter, the Tonkawa Chapter, includes both of these ecoregions.

Source: Wildflowers of Texas by Michael Eason