Erigeron muralis = Erigeron acris subsp. serotinus differs from Erigeron acris subsp. acris mainly by the following attributes: The stem leaves are often distorted, in their axles there are often short sterile shoots, every branch of the inflorescence carries only one anthodium. The stems of Erigeron muralis are usually dark red, those of Erigeron acris subsp. acris are usually green, probably tinged reddish. In Southwest Germany Erigeron muralis is more frequent than Erigeron acris subsp. acris. Both are strongly pilose, which is a difference to Erigeron acris subsp. angulosus.