Heracleum mantegazzianum, Sommier & Levier

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1981, Flora Europaea. Volume 2. Rosaceae to Umbelliferae, Cambridge University Press : 366

9. H. mantegazzianum Sommier & Levier , Nuovo Gior. Bot. Ital. nov. ser., 2: 79 (1895).

Biennial, monocarpic, or perennial. Stem 200-500 cm, up to 10 cm in diameter, usually with conspicuous purple blotches. Leaves up to 300 cm, ternate, or ternately or pinnately divided in varying degree, with lateral segments up to 130 cm, pinnately lobed, acute, shortly pubescent beneath. Umbels up to 50 cm in diameter, with 50-150 rays. Petals up to 12 mm, white or rarely pinkish, outer radiate. Fruit (7—)9—11 x 6-8(-10) mm, glabrous to villous; vittae strongly swollen, 0-5-1 mm wide or more. Widely naturalized in Europe. [Au Br Cz Da Fe Ga Ge Hb He Ho Hu It No Rs (C) Su.] (5. W. Asia.)

The taxonomy and nomenclature of the naturalized plants from S.W. Asia require further investigation. They are very variable in duration, height, shape, dissection and pubescence of the leaves, shape and size of fruit, etc., and probably represent more than one species. Perennial plants with leaves pinnately divided into 5 segments may perhaps be referable to H. lehmannianum Bunge , Del. Sem. Horti Dorpat. 1849: 2 (1850), from C. Asia. H. persicum Desf. ex Fischer in Fischer, C. A. Meyer & Avé-Lall., Ind. Sem. Horti Petrop. 7: 50 (1841) (? H. amplissimum Wenderoth ) is probably distinct and occasionally naturalized; it is like 9 but rarely more than 200 cm high, and usually has 2 pairs of lateral leaf-segments. H. laciniatum auct. scand., non Hornem., naturalized in Norway to 70° N and possibly also in Finland, has the leaves pinnately divided into 5(-7) segments and smaller (7-11 mm) fruit than typical H. mantegazzianum', it may be identical with H. persicum .

For other cultivated species, which may occasionally escape, see Thellung in Hegi, III. Fl. Mitteleur. 5(2): 1421-1427 (1926).