A Gram-stain-positive, aerobic, motile, rod-shaped, endospore-forming bacterium, designated strain R55T, was isolated from the liverwort Herbertus sendtneri growing at Gawalong glacier, Tibet, and characterized by using a polyphasic taxonomic approach. The major fatty acids of strain R55T were anteiso-C15 : 0, C16 : 0 and iso-C16 : 0. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were the predominant polar lipids and occurred along with two unidentified aminophospholipids, one unidentified phospholipid and one unidentified aminolipid. Strain R55T contained MK-7 as the dominant menaquinone and meso-diaminopimelic acid as the major diagnostic diamino acid in the cell-wall peptidoglycan. The G+C content of the genomic DNA was 36.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain R55T was affiliated to species of the genus Paenibacillus, and was related most closely to Paenibacillus ferrarius CY1T (97.1 % similarity). However, the DNA-DNA relatedness between this strain and strain R55T was only 44.1 %. Based on phenotypic, chemotaxonomic and phylogenetic properties, strain R55T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus marchantiophytorum sp. nov. is proposed. The type strain is R55T ( = CGMCC 1.15043T = DSM 29850T).