Tree Blog

Quercus gambelii x macrocarpa | New Mexico

This photo shows a leaf from the previous tree, nestled into an ancient and well-integrated wound in the tree itself. Here we see the deep sinusing associated with Q. macrocarpa, combined with the lobe arrangement typical of Q. gambelii. The leaf form somewhat suggests that Gambel Oak parent is somewhat dominant, whereas the growth habit of the overall tree suggests Q. macrocarpa. In taxonomy, there are considered two broad divisions among those people who identify plants. There are the lumpers, and then there are the splitters. Lumpers prefer to place wide ranges of morphological traits within the umbrella of a single species. Splitters, on the other hand, look for ways and names to classify the irregularities that occur at the edges of species, reserving the species designation for individuals that match the most iconic form of the plant type. Lumpers would describe this tree as simply an extreme form of Q. gambelii, a species which would then include both 100-foot forest trees, along with stoloniferous shrubs barely reaching 3 feet in height. For splitters, this grouping loses a tremendous amount of useful information, so they focus on the mixed species heritage common to many plants. Splitters might term this tree Q. gambelii x macrocarpa, and perhaps a long-stabilized form, giving lead parentage to the local form.

Dave Muffly