The narrow, long, linear leaves of Pentameris eriostoma grow from the tuft base. There are no glands present on the rigid hairless blades. The leaves are mostly rolled in from the lateral margins. There are ligules, dense hair fringes at the leaf bases, commonly found on members of the Pentameris genus. The leaf sheaths and sheath mouths of P. eriostoma are white woolly.
Leaf dimensions are about 40 cm long and 1,5 cm wide.
The specific name, eriostoma, is formed from the Greek words erio meaning wool and stoma meaning leaf pore, referring to the woolliness (Euston-Brown and Kruger, 2023; Curtis-Scott, et al, 2020; Bond and Goldblatt, 1984; iNaturalist; https://www.selinawamucii.com; https://www.worldfloraonline.org).