Diffuse-Spotted Knapweed hybrids
are common and grow where Diffuse Knapweed is found. Flowers are purple or white.
Bracts have a dark tip (similar to Spotted Knapweed) and long bristles on the
margins (similar to Diffuse Knapweed).
The hybrid plants reproduce, and often neither Diffuse nor Spotted Knapweed are
growing near the hybrid populations. It is believed the hybridization occurred
long ago before the knapweeds were brought to North America. Hybrid seeds were
imported and have spread. There is no evidence of continued hybridization between
the two species.