Mapleleaf Oak

Quercus acerifolia is known only from four localities in Arkansas: Magazine Mountain, Logan County; Porter Mountain, Polk County; Pryor Mountain, Montgomery County; and Sugarloaf Mountain, Sebastian County (N. Stoynoff and W. J. Hess 1990; G. P. Johnson 1992, 1994). Some specimens suggest hybridization with Q . marilandica and/or Q . velutina , but no hybrids have been reported.

Trees or shrubs , deciduous, to 15 m. Bark dark gray to almost black, sometimes becoming rough and furrowed. Twigs grayish brown to reddish brown, 1.5-3(-3.5) mm diam., glabrous or sparsely pubescent. Terminal buds gray to grayish brown, ovoid or broadly ellipsoid, 3.5-5.5 mm, glabrous. Leaves: petiole 20-45 mm, glabrous. Leaf blade oblate to broadly elliptic, 70-140 × (60-)100-150(-180) mm, base cordate-truncate to obtuse, margins with 5-7(-9) lobes and 11-48 awns, lobes ovate-oblong or markedly distally expanded, the middle or apical pairs often overlapping, apex acute; surfaces abaxially glabrous or with prominent axillary tufts of tomentum, occasionally with scattered pubescence, adaxially glabrous, secondary veins raised on both surfaces. Acorns biennial; cup saucer- to cup-shaped, 4-7 mm high × 10-20 mm wide, covering 1/4-1/3 nut, outer surface glabrous or puberulent, inner surface light brown to red-brown, glabrous or with ring of pubescence around scar, scales often with pale margins, tips tightly appressed, obtuse or acute; nut ovoid to oblong, 10.5-20 × 9-15 mm, glabrous or pubescent, scar diam. 5-9 mm.

Ark.

Flowering spring.

Dry glades, slopes, and ridge tops; of conservation concern; 500-800m.

Quercus shumardii Buckley var. acerifolia E. J. Palmer

Quercus acerifolia (also called maple-leaf oak) is a rare North American species of oak in the red oak section of Quercus (known as Lobatae). It is endemic to just four locations within the Ouachita Mountains of the State of Arkansas.

The tree sometimes reaches a height of 15 meters (50 feet). The venation of the leaves shows them to be technically pinnately five-lobed but with the two middle lobes larger than the other three. This makes the leaves appear palmately lobed at first glance, similar to many maple leaves. The epithet acerifolia means "maple-leaved."

The species is threatened by habitat loss throughout its fragmented range.

Groves of the tree are under cultivation in several locations, notably Stephens Lake Park Arboretum in Columbia, Missouri.