Quercus suber | Santa Cruz
One of the most proven, if inconsistent, of the non-native oaks utilized in California over the last century and a half is the famous Cork Oak (Quercus suber). Here we see it growing under unusual conditions, in Santa Cruz, as a pair of rather old street trees. These trees have been pruned for the power lines above for many years, well beyond the 20 years that these trees have been directly observed. The soils in this part of Santa Cruz are quite good, and support some of the largest trees in town. Cork Oak is evolved for just this type of Mediterranean soil condition, and these trees appear to be deeply rooted, given the size of the trunks and the small sidewalk openings. Of special note is the "elephant's foot" aspect of the trunk on the right, as the trunk grows out over the curb, rather than lifting it. This type of trunk behavior has been seen elsewhere in coastal California, particularly with London Plane Trees (Platanus x hispanica).