Maximum likelihood phylogeny of Selaginella densiciliata and its allies in subg. Heterostachys. based on molecular data. The numbers associated with branches are maximum likelihood bootstrap support (MLBS) ≥ 50% and Bayesian posterior probability (BIPP) ≥ 0.50; the dash (--) indicates MLBS < 50% or BIPP < 0.50; the asterisk indicates MLBS = 100 or BIPP = 1.00; omitted support values indicate both MLBS < 50% and BIPP < 0.50. Sections followed Zhou and Zhang (2015)’s classification.