Scientific Name
Quercus acutissima
This is one of the few Asian species of oak that is well adapted to our region and that has been planted here long enough to have grown to a large size. This tree is one of the most noteworthy on the campus because it marks the beginning of the Regis Arboretum and the acquisition of unusual kinds of trees. This was first accomplished by Father Jack Callahan, a member of the Regis administrative staff in the 1980s who became interested in arboriculture. He found a small potted sawtooth oak in a local nursery at the end of the season, on sale because no one apparently had any idea what it was. He planted it on the Boettcher South Commons, and it has now grown into the largest one of its species in Colorado, with a height of 39 feet, a trunk diameter of 17 inches and a crown spread of 42 feet. Record keeping for the arboretum was somewhat spotty in the early years, so this is one of the few older trees for which we have a close estimate of its age.
Sawtooth oak grows faster than most oaks and is adaptable to most sites except those with high alkalinity. The leaves are quite narrow for an oak and have no lobes, instead having fine saw teeth tipped with thin (but not unfriendly) bristles. The leaves are quite yellow when emerging in the spring and color golden in the fall. They dry brown and often persist on the tree until the following spring. The bitter acorns require two growing seasons to mature and have an interesting ruffly-scaled cap that covers around two-thirds of the nut. Denver appears to be near the limit of this tree’s cold hardiness, so care should be taken when planting it outside the city, especially in their first few years.
Sawtooth oak has been widely planted in some rural areas of the eastern U.S. as a food source for wildlife because it bears relatively heavy acorn crops less cyclically than other oaks. The acorns appear to be greatly appreciated by turkey and other fowl. However, the species has become naturalized in some areas to the point of being considered invasive, though that is unlikely to be a problem in our colder and drier climate.