About Juglans microcarpa Berl.
Juglans microcarpa Berl., commonly called little walnut, Texas walnut, Texas black walnut, or little black walnut, belongs to the black walnut group Juglans sect. Rhysocaryon. This species grows as a large shrub or small tree, reaching 10 to 30 feet in height. It grows wild along streams and ravines across Texas, New Mexico, Oklahoma, Kansas, and the northernmost states of Mexico. It can be found at elevations between 700 feet and 6700 feet. It produces nuts that measure 1/2 to 3/4 of an inch in width. Its pinnately compound leaves hold 7 to 25 untoothed to finely-toothed leaflets, each of which is 1/4 to 1/2 inch wide. Two varieties of this species are currently recognized: J. microcarpa var. microcarpa and J. microcarpa var. stewartii. Where the range of J. microcarpa overlaps with that of J. major, the two species interbreed, forming populations that show intermediate characteristics. This same interbreeding phenomenon has also been observed where J. microcarpa grows near J. nigra trees. The genus name Juglans is the Latin term for walnut, and translates literally to "Jupiter's acorn". The species epithet microcarpa means "having small fruit". Although the nuts of this species are very small, the seeds inside them are edible.
