Cirsium × stroblii (Cirsium greimleri × spinosissimum) is a hybrid between C. greimleri and C. spinosissimum.
3 herbarium specimens as of 2020.[1]
It is found only in the Rottenmann and Wölz Tauern, although the range overlap extends to nearby ranges.
There are few specimens, but it is close in appearance to C. heterophyllum × spinosissimum, differring in having broader leaves with short lobes, without tomentose undersides.[2]
The description of von Halácsy:
Identified by August von Hayek in the summer of 1906 from a specimen collected on the slopes of a ravine that feeds the Großer Bösenstein lake by Gabriel Strobl in 1867.[3]