Oak, Sawtooth

Quercus acutissima, the Sawtooth Oak, is an oak originally native to eastern Asia, in China, Korea and Japan. It is now also present in North America. It is closely related to the Turkey Oak, classified with it in Quercussect. Cerris, a section of the genus characterized by shoot buds surrounded by soft bristles, bristle-tipped leaf lobes, and acorns that mature in about 18 months. It is a medium-sized deciduous tree growing to 80–100 feet tall with a trunk up to 5.0 ft diameter.

The LEAVES are 3–8 in. long and 1.0–2.5 in. wide, with 14-20 small saw-tooth like triangular lobes on each side, with the teeth of very regular shape. They are alternate, simple, lanceolate in shape, pinnately veined with a very sharply serrate margin bearing bristle-tipped teeth. Strongly resembles a Castanea leaf.

The FLOWERS are wind-pollinated catkins. Male catkins are golden and pendant, appearing in the spring; female catkins are borne on spikes, appearing with the leaves.

The FRUIT is an acorn, maturing about 18 months after pollination, 0.8–1.2 in. long and 0.8 in. broad, bi-colored with an orange basal half grading to a green-brown tip. The cap covers 1/2 of nut with scales that are very prominently reflexed so it resembles hair. Among the first acorns to ripen in the fall after two years.

The BARK is dark gray, ridged and deeply furrowed even when young, later deeply ridged and furrowed, somewhat corky.

The TWIGS are quite slender, red to gray-brown in color with multiple terminal buds; buds are gray-brown, pubescent on the bud scale edges and somewhat pyramidal.

WILDLIFE: The acorns are very bitter, but are eaten by jays and pigeons; squirrels usually only eat them when other food sources have run out. The sap of the tree can leak out of the trunk. Beetles, Stag beetles, butterfly, Vespa mandarinia japonica gather to reach this sap.

INVASIVE: Most planting in North America was carried out for wildlife food provision, as the species tends to bear heavier crops of acorns than other native American oak species; they also grow at a faster rate which helps it compete against other native trees, therefore becoming a problem invasive species in some areas and states.