Strain R33T, an endophyte recovered from Herbertus sendtneri, was identified as representing a novel species of the genus Paenibacillus by using a polyphasic taxonomic approach. The novel strain was observed to be a Gram-stain positive, aerobic, rod-shaped, motile and endospore-forming bacterium. The major polar lipids of strain R33T were identified as diphosphatidylglycerol, phosphatidylethanolamine, along with lesser amounts of phosphatidylglycerol, three unidentified aminophospholipids, two unidentified phospholipids and two unidentified lipids. The predominant isoprenoid quinone was identified as MK-7. The major fatty acids (>8.0 %) were found to be anteiso-C15:0 (40.0 %), C16:1 ω11c (9.4 %), C16:1 ω7c alcohol (8.5 %) and C16:0 (8.2 %). The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. The G+C content of genomic DNA was determined to be 56.9 mol%. The 16S rRNA gene sequence similarities of strain R33T to other Paenibacillus species ranged from 91.6 to 97.2 %, with high similarities to Paenibacillus humicus PC-147T and Paenibacillus pasadenensis SAFN-007T. The phylogenetic analyses based on 16S rRNA gene sequences and the partial rpoB gene confirmed that strain R33T belongs to the genus Paenibacillus. However, strain R33T shows differential molecular characteristics compared to other related Paenibacillus species based on 16S rDNA-RFLP analyses; the DNA–DNA relatedness values between strain R33T and P. humicus PC-147T, and that between strain R33T and P. pasadenensis SAFN-007T, were 35.0 ± 2.0 and 41.4 ± 0.9 %, respectively. Based on its phenotypic, chemotaxonomic and phylogenetic properties, strain R33T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus herberti is proposed (type strain R33T = CGMCC 1.15042T = DSM 29849T).