Shi Shang Bai

Selaginella doederleinii is a perennial evergreen spikemoss (lycophyte) of the family Selaginellaceae, native to shaded, humid forested slopes and stream banks in southern China, Taiwan, Japan, and parts of Southeast Asia. It forms loose mats with creeping primary stems that root at the nodes, giving rise to erect or ascending, repeatedly branched leafy shoots 15 to 45 cm tall. The shoots bear two ranks of larger lateral leaves and two ranks of smaller appressed median leaves, all bright green and finely toothed. Tetragonal strobili up to 1 cm long terminate the upper branches, containing both megaspores and microspores, which is characteristic of the heterosporous Selaginella. The entire aerial plant is collected year-round for medicinal use.