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