The description is based on the data of Hildebrand & Schroth (1967), Hauben et al. (2005) and this study. Cells are Gram-negative-staining short rods (0.5–1.0×1.0–2.0 µm) occurring singly, in pairs or in groups. Motile by peritrichous flagella. Facultatively anaerobic, oxidase negative but catalase positive. Optimum temperature for growth is 28–30 °C. Colonies are white to cream on tryptone soya agar, round, convex and smooth with entire margins. Negative in tests for β-galactosidase, arginine dihydrolase, lysine decarboxylase, ornithine decarboxylase and tryptophan deaminase activities. Citrate is utilized but no production of H2S, urease, indole or gelatinase. Nitrates are not reduced to nitrites. Acid is produced from N-acetylglucosamine, arbutin, d-fructose, d-glucose, d-mannose, methyl α-d-glucopyranoside, d-ribose, salicin, sucrose and turanose. Major fatty acids are C14:0, C16:0, C18:1ω7c, C17:0 cyclo and summed features 2 (iso-C16:1 and/or C14:0 3-OH) and 3 (C16:1ω7c and/or iso-C15:0 2-OH). Members of the genus Lonsdalea form a phylogenetic clade as determined by both 16S rRNA gene sequence analysis and MLSA based on four housekeeping genes. Members of the genus may cause disease on oak trees including drippy nut disease and bark canker and may be associated with Acute Oak Decline. The DNA G+C contents range from 54.5 to 55.1 mol%.

The type species is Lonsdalea quercina.

The description is as given above for the genus with the following additional characteristics. Acetoin reaction is variable. Acid is produced from N-acetylglucosamine, arbutin, aesculin ferric citrate, d-fructose, d-glucose, d-mannitol, d-mannose, methyl α-d-glucopyranoside, d-ribose, salicin, sucrose and turanose. The following carbon sources are utilized at 28 °C: N-acetyl-d-glucosamine, d-fructose, d-galactose, d-glucose, d-mannitol, d-mannose, methyl β-d-glucoside, d-psicose, sucrose, turanose, citric acid, d-gluconic acid, bromosuccinic acid, l-aspartic acid, glycerol and d-glucose 6-phosphate. The following carbon sources are not utilized at 28 °C: dextrin, glycogen, adonitol, l-arabinose, d-arabitol, d-cellobiose, erythritol, l-fucose, gentiobiose, inositol, lactose, lactulose, maltose, d-melibiose, l-rhamnose, d-sorbitol, xylitol, d-galacturonic acid and l-serine.

Type strain: LMG 2724T ( = ATCC 29281T = CCUG 48867T = CFBP 3617T = CIP 105201T = DSM 4561T = ICMP 1845T)