Ochsmann, J. 2001:
On the taxonomy of spotted knapweed (Centaurea stoebe L.). In: Smith, L.
(ed.): Proceedings of the First International Knapweed Symposium of the Twenty-First
Century, March 15-16, 2001, Coeur d’Alene, Idaho. USDA-ARS, Albany, California.
33-41. [Download
proceedings as pdf] |
Spotted knapweed was
introduced into North America as a seed contaminant from south-eastern Europe in the
middle of the 19th century. Today it is a well-known noxious weed in USA and Canada
causing economic problems by infesting farm land.
Native to western, central, and eastern Europe spotted knapweed consists of a group of
closely related taxa. For the taxonomy and nomenclature various different concepts have
been used by different authors resulting in great confusion.
During recent studies the delimitation of the different taxa of spotted knapweed was
investigated by using morphological and molecular techniques. According to this work Centaurea
maculosa LAM. (described from Central France), as well as C. rhenana BOREAU,
are synonyms of Centaurea stoebe L. subsp. stoebe, which is native to western and
central Europe only. These plants are biennial, strictly monocarpic and diploid (2n = 18).
All the North American plants called “Centaurea maculosa” are
perennial, polycarpic and tetraploid (2n = 36) and thus must belong to a different taxon.
Parallel to the introduction into North America similar plants spread all over Europe.
Molecular data confirm that the plants introduced into North America and into Europe
belong to the same taxon. Their correct name is Centaurea stoebe L. subsp. micranthos
(GUGLER) HAYEK (synonyms are “C. biebersteinii” and “C.
micranthos”). |