The following table emphasizes the differences between the two species:[4][5] The marginal flowers of Heracleum sphondylium are typically zygomorphic (with bilateral symmetry), whereas the marginal flowers of Heracleum sibiricum are actinomorphic (with radial symmetry) or nearly so.

An atypical form of Heracleum sphondylium may appear to be glabrous to the naked eye but in fact it has short, stiff, ascending hairs with pointy tips.

[6] The specific name sibiricum suggests the taxon occurs in Siberia, a fact mentioned by Linnaeus in his description.

In 1887, the Hungarian botanist Lajos Simonkai reduced its taxonomic rank to a subspecies of Heracleum sphondylium.

In 1961, the Polish botanist Maria Gawłowska described Heracleum sibiricum f. rarum,[16] a form of var.

[10] Authorities claim the taxon is widely introduced throughout North America,[2][12] but as of August 2023[update], the presence of Heracleum sibiricum in eastern Canada and New England has not been confirmed.

[20][21][22][23] Heracleum sibiricum is most commonly a polycarpic perennial (not a biennial as often claimed), but approximately one-fourth of individuals are monocarpic.

[24] As of August 2023[update], the global conservation status of Heracleum sphondylium subsp.