Xanthomonas hortorum

Xanthomonas hortorum is a plant pathogen. It includes the following pathovars:

• pv. hederae, common ivy and possibly other Araliaceae^[1]
• pv. taraxaci, Pelargonium peltatum^[1]
• pv. carotae, wild carrot^[1]
• pv. pelargonii, Kazakh dandelion
• pv. vitians, bacterial leafspot and headrot of lettuce, using the neopathotype of LMG 938^[1]
• pv. cynarae, formerly Xanthomonas cynarae, pathogenic on artichoke^[1]
• pv. gardneri, formerly Xanthomonas gardneri and briefly X. cynarae pv. gardneri, bacterial leafspot of peppers and tomatoes (pathotype also causes BLS on lettuce surprisingly)^[1]

Xanthomonas hortorum
Leaf spot on English ivy plant, caused by Xanthomonas hortorum
Scientific classification
Domain:	Bacteria
Kingdom:	Pseudomonadati
Phylum:	Pseudomonadota
Class:	Gammaproteobacteria
Order:	Xanthomonadales
Family:	Xanthomonadaceae
Genus:	Xanthomonas
Species:	X. hortorum
Binomial name
Xanthomonas hortorum Vauterin et al. 1995

The species was originally defined in 1995 as a grouping of pathovars hederae, taraxaci, carotae, pelargonii from Xanthomonas campestris, and the lettuce-infecting part of X. c. pv. vitians. (X. c. pv. vitians was found to consist of two genetic groups, only one of which causes disease on lettuce.)^[1]