The gametophytes of four tropical, terrestrial species of Huperzia – H. crassa, H. cumingii, H. hypogaea, and H. saururus – grow in axenic culture on a nutrient medium containing inorganic nutrients and glucose. The gametophytes of all species are dorsiventral, axial structures, which can be straight, curved, narrow, or wide. Paraphyses and gametangia form on the dorsal surface and rhizoids on the ventral surface. The apical meristem is overarched by immature dorsal tissue. Minor differences in the paraphyses and gametangia exist among the species. These gametophytes are Type III gametophytes as is the case for the previously described gametophytes of two other terrestrial species of Huperzia.