Description from Flora of China
Trees 8-15 m tall; branchlets, petioles, and rachis of inflorescences densely covered with rust-colored simple and branched hairs. Petiole 1-2 cm; leaf blade obovate to obovate-elliptic on sterile shoots, sometimes elliptic on fruiting branches, 16-30 × 5-12 cm, subleathery, rusty pilose, adaxially with hairs crisp and early glabrescent, base broadly cuneate, margin entire, apex acute; secondary veins 11-17 on each side of midvein, abruptly curving apically near margin, apical ones fusing; tertiary veins abaxially slender, evident, subparallel. Male panicle terminal or rarely solitary spikes in axils of leaves, to 25 cm. Female inflorescences to 30 cm; cupules in clusters of ca. 3. Infructescence rachis to 1 cm thick. Cupule depressed globose, 1.5-2 × 2.5-3 cm, entirely or almost completely enclosing nut, wall 0.5-1.5 mm thick; bracts imbricate, ovate-triangular, appressed, puberulent. Nut depressed globose, 2.2-2.7 cm in diam., glabrous, wall 0.5-1 mm thick; scar 1.5-1.8 cm in diam., ± concave. Fl. Sep-Oct, fr. Oct-Dec of following year.
Lithocarpus rhabdostachyus subsp. rhabdostachyus occurs in Laos and Vietnam.
Broad-leaved evergreen forests, 900-2200 m. W Guangxi, SE Yunnan [C to N Vietnam]