Heracleum, Linnaeus, 1753

Kljuykov, Eugene, Lyskov, Dmitry, Ukrainskaja, Uliana, Samigullin, Tahir & Terentieva, Elena, 2021, Heracleum piliferum (Apiaceae), a new species from central Nepal, Phytotaxa 500 (3), pp. 166-178 : 176

Key to species of Nepalese Heracleum s.l.

1. Leaves twice pinnatisected or twice trilobate.....................................................................................................................................2

– Leaves pinnatisected or trilobate ........................................................................................................................................................3

2. Leaves twice pinnatisected, nearly glabrous, calyx teeth obsolete, umbels with 22–30 rays, marginal ribs narrower than body of mericarp............................................................................................................................................................... Heracleun piliferum

– Leaves twice pinnatisected or twice trilobate, pubescent, calyx teeth well developed, umbels with 6–16 rays, marginal ribs two times as wide as body of mericarp .................................................................................................................. Tetrataenium wallichii

3. Terminal lobes of leaves lanceolate................................................................................................................................. T. sublineare

– Terminal lobes of leaves obovate, elongate, or obovate-orbicular.....................................................................................................4

4. Plants weak and reclining, calyx teeth prominent, to 1 mm long..................................................................................... T. canescens

– Plants stout, calyx teeth merely evident to obsolete...........................................................................................................................5

5. Leaf blades elongate, secretory ducts between dorsal ribs solitary, between marginal and dorsal ribs binary........................ T. lallii

– Leaf blades obovate, secretory ducts between all ribs solitary ..........................................................................................................6

6. Fruit wings definitely broader than body. Leaflets sparsely hirsute beneath ................................................................... T. nepalense

– Fruit wings narrower than to equal in width to body. Leaflets densely gray-hirsutulous to with tomentose beneath .......................7

7. Leaves pinnate or ternate-pinnate, the 5-9 leaflets oblong to ovate ................................................................................. T. candicans

– Leaves pinnately parted or pinnatifid to simple pinnate, the 3 or 5 leaflets ovate-orbicular ....................................... T. obtusifolium