Chisos Red Oak

The Chisos Red Oak (Quercus gravesii) is a medium-sized deciduous oak native to the mountain ranges of the Trans-Pecos region of Texas and extending into adjacent areas of northeastern Mexico, including the Sierra Madre Oriental foothills. It belongs to the red oak group (section Lobatae) within the family Fagaceae, characterised by leaves with lobes ending in bristle tips and acorns that take two seasons to ripen. Quercus gravesii typically grows on rocky slopes and canyon walls at mid to high elevations, forming part of diverse Madrean woodland and pinyon-juniper communities alongside other oaks, junipers, and conifers. Its foliage turns red and orange in autumn, providing a striking display in the typically muted desert mountain landscape. The species is an important component of its ecosystem, providing food and habitat for numerous birds and mammals; acorns are consumed by jays, woodpeckers, deer, and small rodents. Hypnotic hybridisation with related oak species is documented in areas of sympatry. The IUCN classifies Chisos Red Oak as Least Concern, with populations considered stable across its range. It is well represented within protected areas including Big Bend National Park and the Davis Mountains. Threats are limited but include drought stress exacerbated by climate change and browsing pressure from white-tailed deer.