Sagina maxima is an annual herb distributed in East Asia and North America. In this study, we sequenced and characterized the chloroplast genome (cp.) of S. maxima. The complete cp. genome of S. maxima is 151,507 bp long and comprises a large single-copy (LSC) region (83,669 bp), a small single-copy (SSC) region (17,220 bp), and a pair of inverted repeats (IRs) (25,309 bp) with 36.6% GC content. A unique set of 112 genes were identified which includes 78 protein-coding genes, 30 tRNA and 4 rRNA. Total 18 genes were duplicated within the IR regions and 16 genes have one intron and only clpP gene with two introns. LSC/IR junction located in the rps19 while SSC/IR junction located in ycf1. The average number of codon usage is 26,080 for all protein-coding genes in the cp. genome. There were 26 long repeats and 40 simple sequence repeats in the cp. genome, which were mostly, located in intergenic spacer (IGS) regions. This study provides the first brief characterization report of the cp. genome from the genus Sagina, which will be useful in future investigations into the genetic resources, species identification, and phylogeny of Sagina.
