[5] The adaxial (upper) surface of the leaves are greenish or yellowish with short semi-erect hairs; the secondary veins are obscure, dense or scattered.

The abaxial (lower) surface of the leaves are covered with erect rayed hairs 1–4 millimetres (1⁄16–3⁄16 in) in length that are felty to the touch with prominent secondary veins.

[6] The acorns of the leather oak can be found solitary or paired at the end of a small stalk; the cup which encloses up to half of the nut is reddish or yellowish with a scaly texture.

[5] In more sheltered, inland areas like MacNab cypress (Hesperocyparis macnabiana) woodlands this shrub can extend into riparian zones where summer fogs persist.

[11] Q. durata is well suited for ultramafic soils which are reddish and typically nutrient poor, having abundant nickel, magnesium, and chromium content while lacking calcium.

Here, Q. durata can be found with shrubs including chamise (Adenostoma fasciculatum), coffeeberry (Frangula californica), buckthorn (Rhamnus crocea) and toyon (Heteromeles arbutifolia).

[5] The climate in Q. durata habitat is characterized by 41 to 170 cm (16 to 67 in) of annual precipitation during a wet season of 3 to 8 months, temperatures range from a December low of 30 °F to a July high of 96 °F.

[12] Based on controlled studies done at Jasper Ridge Biological Preserve the harsh environment of Q. durata limits species re-establishment after forest clearing or in colonization of grassland at chaparral-prairie boundaries.

The dry, exposed slopes of the San Gabriels stretching from La Cañada to Pomona are covered in a chaparral with non-serpentine soils suitable for Quercus durata var.

[15] It is also a host plant for the sleepy duskywing (Erynnis brizo) butterfly, which sometimes feeds on nectar, and the Pacific tent caterpillar moth (Malacosoma constricta).

In a study done by Narvaez et al. in 2000 with a group of goats and sheep at the Hopland Research and Extension Center, it was found that for animals employed in vegetation management programs across grass woodlands and chaparral ecosystems nutritional quality and intake levels of Q. durata and Adenostoma fasciculatum foliage were low and demonstrated a need for diet supplementation in livestock performing as part of vegetation control programs.