Hieracium viscosum subsp. scariolifolium Hieracium viscosum subsp. tarchanum Hieracium viscosum subsp. oxygonum Hieracium viscosum subsp. viscosum Hieracium viscosum subsp. africanum Hieracium viscosum subsp. lactucoides Hieracium viscosum subsp. pseudocerinthopsis Hieracium viscosum subsp. viscosiforme
World Flora Online, http://www.worldfloraonline.org/, accessed June 20, 2024