细秆羊胡子草（学名：Eriophorum gracile）为莎草科羊胡子草属下的一个种。

Eriophorum gracile is a species of flowering plant in the sedge family, Cyperaceae. It is known by the common name slender cottongrass, or slender cottonsedge. Eriophorum gracile is a plant with circumboreal distribution, extending south into mountain ranges of the Northern Hemisphere. It grows in wet areas such as bogs.