A Gram-positive, aerobic, rod-shaped, peritrichously flagellated, round-endospore-forming bacterium was isolated from a forest soil near Braunschweig, Lower Saxony, Germany, and designated strain HR3-23T (T = type strain). Morphologically, strain HR3-23T shows the characteristics of a member of the genus Bacillus. The spore position is terminal in a swollen sporangium. Comparative analysis of the 16S rDNA sequence shows strain HR3-23T to be most closely related to Caryophanon tenue (95.8% 16S rRNA similarity) and to Bacillus sphaericus (95.4% 16S rRNA similarity). Phylogenetically, the isolate clusters among species of Bacillus RNA group 2. The DNA G + C content of isolate HR3-23T is 39.3 mol%, the peptidoglycan type is A4 alpha (L-Lys-D-Glu), the major respiratory lipoquinone is menaquinone MK-7 and the predominant fatty acid is of the iso-C15:0 type. Based on the morphological, chemotaxonomic, physiological and phylogenetic properties, a new species, Bacillus silvestris, is proposed; strain HR3-23T is the type strain (= DSM 12223T).