Quercus arizonica aka Arizona White Oak

Quercus arizonica is also known as Arizona white oak. It belongs to Fagaceae, the beech family. Its native range spans Arizona, New Mexico, and western Texas. It also grows in northern Mexico. It grows in canyons, arroyos, rocky slopes, and open woods. At high sites, it may form shrubs, not full-sized trees. It often keeps its leaves through winter, though some may fall.

Garden size reports differ. They place trees around 26–33 feet [8–10 metres] tall. One gives a spread near 20 feet [6 metres]. Large trees in low canyons can reach 60 feet [18 metres]. Growth is slow. A short trunk holds thick, twisted branches and a wide crown. Young bark is thin and pale gray, with small pores. As bark ages, it thickens and forms shallow cracks and scaly ridges. Light brown twigs have fine hairs. Their pointed buds are reddish-brown.

The stiff, leathery leaves grow in an alternate pattern. They are oblong, with smooth edges or teeth near their tips. Their dull upper sides range from yellow-green to blue-green. Fine hairs coat the duller lower sides. Parallel veins sink into the top and stand out beneath. Each tree bears both male and female flowers. Yellow-green male catkins hang down when new leaves appear. Small female flower spikes grow where leaves meet stems. Wind carries the pollen. Oblong acorns ripen in early fall within a single year. A bowl-shaped cup covers about one-third of each nut.

Give this oak full sun and soil that drains well. It accepts sandy, loamy, or clay soils. Soil can range from mildly acid to mildly alkaline. It grows in dry or moist ground and hot summers. Cool summers in maritime areas can leave wood unripe before winter. Frost may then harm the tree despite its cold tolerance. Sources place it in USDA zones 7–10. Dormant trees can withstand about 5°F [−15°C]. Its deep taproot makes older plants hard to move.

The broad crown and lasting leaves give shape to a landscape. The tree draws wildlife, and people harvest its wood. PFAF reports that people can eat the acorns after thorough leaching. This process reduces tannins. All parts contain tannins, so edible does not mean harmless. Eating too much can cause stomach pain and bowel problems. The supplied sources name no specific pests or diseases.