Juglans microcarpa Juglans microcarpa Juglans microcarpa, known also as the little walnut, Texas walnut, Texas black walnut or little black walnut (as it belongs to the "black walnuts" section "Juglans" sect. "Rhysocaryon"), is a large shrub or small tree (10–30 ft tall) which grows wild along streams and ravines in Texas, New Mexico, Oklahoma, and Kansas. 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"
Juglans hindsii ("Quercus" spp.) and Fremont cottonwood ("Populus fremontii") trees. "Juglans hindsii" has only one confirmed native stand remaining. It is listed as Seriously Endangered on the California Native Plant Society Rare Plant Inventory. The IUCN classification is a Vulnerable species. It is threatened by hybridization with orchard trees, urbanization, and habitat conversion to agriculture. "Juglans hindsii" is a medium-sized tree of short bulky proportions. It grows up to tall, has a single erect trunk, commonly without branches for , and a crown that can be wider than the tree is tall. Trunks commonly reach in diameter near the base of the