Tanacetum parthenium (L.) Schultz-Bip. (syn.: Chrysanthemum parthenium (L.) Bernh., Pyrethrum parthenium (L.) Sm.) (SE-Eur., SW-As.) – A rather commonly naturalised escape from cultivation. Known already in the 18th century from Belgium but poorly documented. Most early records (even in the 19th century) are from hedges or roadsides in the vicinity of gardens and are probably merely ephemeral. From the first half of the 20th century onwards increasingly found on old walls (Coutisse, Diksmuide, Torgny, Wulvergem,…) or rocky slopes (for instance around Namur). Nowadays not rare on walls (often rather damp and nitrophilous), especially in urban habitats; locally well-naturalised. In its native distribution range Tanacetum parthenium inhabits a more or less similar but natural ecological niche (mountain scrub, rocks). Also frequently seen in demolition sites, on wasteland or dumps but usually ephemeral.
The very similar Tanacetum partheniifolium (Willd.) Schultz-Bip. is also cultivated and may have been overlooked. Its leaves are greyish in appearance, densely hairy and leaf segments tend to have sharper apices. It is naturalized in parts of Germany.
 |
 |
Selected literature:
Verloove F. (2006b) Tanacetum parthenium. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 868.