Aristolochia in subgen. Siphisia

Kashung, Soyala, Gajurel, Padma Raj, Singh, Binay, Barman, Rimi & Yakang, Tage, 2022, Aristolochia rethyae, a new species from Arunachal Pradesh, north-east India, Phytotaxa 564 (1), pp. 1-7 : 4-5

Indian Siphisia

With the addition of the present new species, the number of Siphisia species in India has become eight. A key for identification of the Indian species in the subgenus Siphisia is given below.

Keys to the Indian species of Aristolochia in subgen. Siphisia

1a. Limbs saccate, lobe distinct............................................................................................................................................. A. transsecta

1b. Limbs not saccate, lobe distinct or indistinct .....................................................................................................................................2

2a. Limbs bell or trumpet shaped, lobe margin distinctly revolute..........................................................................................................3

2b. Limbs abruptly discoid, lobe margin slightly or non-revolute ...........................................................................................................5

3a. Leaves palmately 3-lobed ............................................................................................................................................. A. platanifolia

3b. Leaves entire.......................................................................................................................................................................................4

4a. Perianth tube 1.5–2 cm long, limb nearly rounded ............................................................................................................. A. saccata

4b. Perianth tube 3–4 cm long, limb nearly rectangular......................................................................................................... A. cathcartii

5a. Flowers on old branches, cauliflorous................................................................................................................................................6

5b. Flowers on young branches, ramiflorous ...........................................................................................................................................7

6a. Flowers in cluster, capsule densely pubescent, apex stipitate ............................................................................................. A. rethyae 6b. Flowers solitary and axillary, capsule lightly pubescent, apex folded ............................................................................... A. griffithii

7a. Perianth glabrescent, limb indistinctly 3-lobed.................................................................................................................. A. dilatata

7b. Perianth villous, limb distinctly 3-lobed ...................................................................................................................... A. punjabensis