Heracleum L.

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 : 364-365

92. Heracleum L. 2

Leaves simple, rarely subentire, usually apparently digitately lobed, or ternatisect, pinnate or 2-pinnate. Calyx-teeth small. Petals white, greenish-yellow or pink. Fruit elliptical or obovate to suborbicular, strongly compressed dorsally, glabrous to villous. Marginal ridges forming a broad wing; dorsal ridges slender; vittae solitary in the furrows, slender or conspicuously swollen at their lower ends, shorter than the fruit.

Zosima absinthiifolia (Vent.) Link, Enum. Hort. Berol. Alt. 1: 274 (1821), has been recorded from the Lower Volga, but the basis of the record is unknown and it is unlikely that a mountain species such as this would occur there. It is like Heracleum but has conspicuous sepals and the fruit has a wide, hyaline wing around which the lateral ridges form a thickened rim.

1 Stems less than 4 mm in diameter, not more than 50(-65) cm high; umbels not more than 7(-9) cm in diameter, with 3—15(—17) rays

2 Leaves glabrous 1. minimum 2 Leaves pubescent, at least beneath

3 Leaves pinnatisect, not suborbicular in outline, with 2-3 pairs of segments 2. austriacum 3 Leaves simple or ternatisect, ± suborbicular in outline

4 Leaves 3-lobed or ternatisect; stem often glandularpubescent 3. orphanidis 4 Leaves palmately 5- to 7-lobed or almost entire; stem not glandular-pubescent 4. carpaticum 1 Stems at least 4 mm in diameter, usually more than 50 cm high;

at least the larger umbels more than 10 cm in diameter, with 12-150 rays

5 Leaves pinnately divided into small segments not more than

3 cm; rhachis and petiolules slender 6. ligusticifolium 5 Leaves simple, or divided into segments more than 3 cm; rhachis and petiolules stout

6 Vittae not or only slightly expanded at their lower end, not more than 0-4 mm wide 5. sphondylium 6 Vittae conspicuously expanded at their lower end, up to

1 mm wide

7 Leaves simple, densely white-tomentose beneath 7. stevenii 7 Leaves ternatisect or pinnatisect, not white-tomentose beneath

8 Plant 60-80 cm; umbels 10-12 cm in diameter; rays 15-20

8. pubescens 8 Plant (17O-)2OO-5OOcm; larger umbels 20-50cm in diameter; rays more than 50 9. mantegazzianum