Abstract
A new species of the firmoss from China, Huperzia crassifolia sp. nov., is described and illustrated based on morphological characters and molecular evidence. The new species resembles species associated with the H. javanica complex, in particular H. javanica based on leaf shape and serrations, but can be easily distinguished by elliptic lanceolate and thick coriaceous leaves, well differentiated seasonal constriction zones, and reflexed leaf margins when get dried. Phylogenomic reconstruction using whole chloroplast genome sequences recovered H. crassifolia as sister to H. sutchueniana and only distantly related to morphological similar species H. javanica, H. nanlingensis, and H. serrata. The genome size 2C = 17.2 pg indicated the new species to be a tetraploid, whereas diploid H. javanica had a genome size of 8.7 pg. Morphological characters, distribution, and conservation status of the new species are also presented.