1. Leaves spreading, complanate; leaf apices rounded to truncate; exostome densely papillose throughout.......
....................................................................................3. S. pygmaeus
1. Leaves imbricate or appressed, not complanate; leaf apices broadly apiculate, acute to shortly acuminate or bluntly acuminate; exostome smooth or finely papillose above..........................2
2. Leaves imbricate, distinctly concave; leaf apices broadly apiculate; leaf margins subentire; leaf cells somewhat projecting................................................................................4. S. weymouthioides
2. Leaves appressed, not or slightly concave; leaf apices acute to shortly acuminate or bluntly acuminate; leaf cells moderately to strongly prorate........................................................................................................... 3
3. Stem and branch leaves clearly differentiated; leaf cells distinctly prorate.................1. S. echinatus
3. Stem and branch leaves somewhat differentiated; leaf cells prorulose............................4
4. Stem leaves gradually acuminate; median leaf cells broader, ca. 12:1........................2. S. perrottetii
4. Stem leaves bluntly acuminate, median leaf cells narrower, ca. 20:1.........................5. S. yuennanensis