1. Plant leafless at anthesis, lip entire, undivided, elliptic-lanceolate, acute, without basal auricles ……………………………………………………………………………... P. laurense

1* Plant leafy at anthesis, lip ±constricted, basally auriculated, lamina not above …………………………………………………………………………………………2

2. Leaves oblong-obovate to elliptic-obovate, 5–6 cm wide ……………………... P. ovatifolium

2* Leaves not as above …………………………………………………………………... 3

3. Lip lamina narrow, strip-like in a basal part, much expanded above, ±ovate ………………………………………………………………………………P. paludosum

3* Lip not as above ……………………………………………………………………….... 4

4. Petals constricted in the apical 5th or 6th, apex obliquely rhombic, acute ……….. P. saltense

4* Petals oblong ligulate, obtuse ……………………………………………………………5

5. Lip distinctly constricted, hypochile oblong triangular to ovate ………………. P. bonariense

5* Lip somewhat constricted, hypochile oblong ……………………………………. P. ekmanii