This is the loblolly bay tree, often confused with Magnolias. Photos show the differences. Magnolia on the left and the Gordonia on the right. The leaves on the magnolia have margins entire and reddish hairs on the undersides. The Gordonia has serrated margins and glabrous undersides of the leaves. The trunk is deeply fissured on mature trees.

Significantly outside previously reported range. Multiple plants including a couple of small trees in two separate groups. Found along lower slopes of wooded valley near creek. In association with mountain-laurel, Piedmont azalea, common sweetleaf, sourwood, chalkbark maple, and common witch-hazel.

Stewartia serrata Maxim. f. sericea (Nakai) H.Hara
トウゴクヒメシャラ

A variety with many hairs on the mid-vein on the underside of the leaves. It is a variety of the species serrata and is considered to be the species f. sericea, but is not classified in POWO.

浜松市竜頭山にて。
葉裏の主脈上に毛があり、「ヒコサンヒメシャラは両面ともに無毛だが、トウゴクヒメシャラは、裏面主脈上に毛が多い。」とWebにあり、悩んでいたものです。
川根町に自生していたものは、葉裏の主脈上に毛が無く、こちらがヒコサンヒメシャラで、葉裏の主脈上に毛のある本種は、トウゴクヒメシャラと考えて良さそうです。