Lagenandra, Dalzell, 1852

Madola, Indrakheela, Yakandawala, Kapila, Yakandawala, Deepthi & Karunaratne, Senani, 2021, Lagenandra wayambae (Araceae), a new endemic species from a freshwater swamp forest of Sri Lanka, Phytotaxa 489 (2), pp. 216-222 : 221

Key to the species of Lagenandra from Sri Lanka

Modified from Nicolson (1987).

1. Spathe distinctly warty outside...........................................................................................................................................................2

– Spathe smooth or merely roughened outside by papillae...................................................................................................................5

2. Warts large (1.5–3.0 mm long); spathe limb abruptly globular-inflated above the kettle....................................................... L. ovata

– Warts small (to 1.0 mm); spathe limb subcylindric............................................................................................................................3

3. Spathe large (more than 10 cm long); pistillate flowers more than 60........................................................................ L. praetermissa

– Spathe small (up to 10 cm); pistillate flowers less than 40 ................................................................................................................4

4. Spathe outside with few distinct irregular warts; leaves linear lanceolate to linear ovate ............................................. L. wayambae

– Spathe outside, rugose, not with distinct warts; leaves broadly elliptic or broadly lance-ovate...................................... L. lancifolia

5. Leaf-blade sublinear, c. 10 × longer than broad.................................................................................................................................6

– Leaf-blade ovate-lanceolate, to 5 × longer than broad.......................................................................................................................7

6. Leaf-blade to 50 cm long, margins smooth; inside of spathe limb strongly laterally ribbed, outside dark purple ............. L. koenigii

– Leaf-blade to 20 cm long, margins erose; inside of spathe limb rugose spongy, outside green ............................................. L. erosa

7. Spathe limb strongly twisted to one side, inflated and opening subhorizontally; outside of spathe limb whitish, inside black-purple and with tan, branched, hair-like protuberances.............................................................................................................. L. jacobsenii

– Spathe limb sub-erect, cylindrical and opening subvertically; outside of spathe limb purplish, inside with inconspicuous purplish protuberances......................................................................................................................................................................................8

8. Peduncle c. 2 cm; leaf blades often silver margined; stigma unequal; female flowers subscabrid on sides.................... L. thwaitesii

– Peduncle 7–12 cm; leaf blades not silver margined; stigma dome-shaped; female flowers with long protuberances below stigma .. ............................................................................................................................................................................................. L. bogneri