Huperzia nutans, a member of the Lycopodiaceae (club moss) family, is a clumped club moss that is terrestrial or epiphytic up to 50 cm (20 in) tall. A mature plant consists of a cluster of several erect stems arising from the plant’s base. The stems may be unbranched, once-forked, or twice-forked. The sterile leaves are lanceolate, 13 to 20 mm (0.5 to 0.8 in) long and 2 to 3.5 mm (0.08 to 0.14 in) wide and are arranged in six ranks of leaves along the stem. The strobili (sporangia-bearing structures densely aggregated along a stem) arise from the ends of all mature branches, curve downward, and are simple, or are branched once or twice. The sterile leaves on the stems gradually transition into the smaller fertile leaves on the strobili. The fertile leaves measure 10 to 20 mm (0.4 to 0.8 in) long and 1.5 to 2.5 mm (0.06 to 0.1 in) wide and bear reproductive sporangia in the axils.