﻿AbstractOver the course of the recent decade, the composition ofAlsineaehas been drastically changed by means of molecular phylogeny. However, the genusBrachystemmahas not been sampled in any of the previous studies, and its phylogenetic position is still pending. In addition, the related speciesStellariaovatifolia, which has at times been placed inBrachystemma,Schizotechium, orStellaria, has also not been sampled. Here, nuclear ribosomal internal transcribed spacer (ITS) and four plastid regions (trnL-F,matK,rbcL,rps16) were used to conduct phylogenetic analyses withinCaryophyllaceaeand the tribeAlsineae. Ancestral characters (petal margin and number of seeds) were reconstructed in the tribeAlsineaebased on the phylogenetic results. Our results indicate thatBrachystemmais nested in the tribeAlsineaeand forms a monophylum withS.ovatifolia, and apically lobed petals and numerous seeds may be the ancestral characters in the tribeAlsineae. Based on our study,Stellariaovatifoliashould be considered withinBrachystemma, andBrachystemmais clearly a separate genus and now includes two species.