Juglans microcarpa, known also as the Texas Walnut and the Little Black Walnut is a large shrub or small tree (10–30 ft tall) which grows wild along streams and ravines in Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

, New Mexico

New Mexico

New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

, Oklahoma

Oklahoma

Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...

, and Kansas

Kansas

Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

. It produces nuts with a width of 1/2—3/4 in. The pinnately compound leaves bear 7—25 untoothed to finely-toothed leaflets, each 1/4—1/2 in wide. It is found at elevations ranging from 700 ft to 6700 ft.

Two varieties are recognized: J. microcarpa var. microcarpa and J. microcarpa var. stewartii.

Where the range of J. microcarpa overlaps with J. major

Juglans major

Juglans major is a walnut tree which grows to with a DBH of up to at elevations of 1000–7000 ft in Texas, Oklahoma, New Mexico, Arizona, and Utah. Common names include Arizona Walnut and Nogal....

, the two species interbreed, producing populations with intermediate characteristics. This phenomenon has also been found where J. microcarpa trees grows near J. nigra trees.

Juglans (literally "Jupiter's acorn") is the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

name of the walnut. Microcarpa means "having small fruit".