Some weeds are actually quite attractive. One of these is Centaurea biebersteinii or spotted knapweed which resembles Batchelor Buttons, also in the genus Centaurea. Both species are in the Aster family, Asteraceae. The short lived perennial has alternate leaves that are pinnately lobed and grey-green in color. The flower heads lack disk flowers but have numerous thread-like pink to purplish pink ray flowers (see photo below). The head is subtended by distinctive bracts that are ovate in shape tapering to a black tip. Bloom time lasts from mid-summer into early fall followed by the development of achenes (fruits) that have a crown of bristles on top that aid in disbursement. The roots produce a toxin that can destroy the root systems of other plants thus contributing to the invasiveness of the species. Spotted knapweed occurs along roadsides, railroad tracks, waste areas, eroding slopes, pastures, abandoned fields and vacant lots in cities. Naturally occurring in Eastern Europe, it was introduced into North America in the 1890’s and now appears widespread across U.S. and Canada It does have some redeeming characteristics in that the flowers attract long tongued bees, and butterflies.
