Nymphaea oxypetala

Unlike most other waterlilies, this species rarely produces floating leaves. The strongly reduced floating leaves are only produced very rarely.^[3] The smaller floating leaves are up to 6 cm large. The purplish-green, submerged, saggitate, membranous leaves are significantly larger with up to 30 cm big leaf blades.^[4] The broad submerged leaves display a likeness to the leaves of lettuce.^[5] The petioles are fragile and leaves break of easily.^[3]

The nocturnal flowers float on the water surface.^[3] The stamens are purple. The cream-coloured, 2 cm long carpellary appendages are abruptly folded at the apex.^[4] They are the longest carpellary appendages of all Nymphaea species.^[3] The floral fragrance has been described as ether-like.^[6]

The chromosome count of this polyploid species is 6n = 84.^[7]

This species is likely not stoloniferous.^[6] Proliferating pseudanthia are also lacking in Nymphaea oxypetala.^[8][9]

Flowering occurs throughout March to August.^[4]

It is associated with lotic habitats,^[10] These aquatic habitats are defined by the presence of moving water.^[11] It occurs in floodplains, river branches and in seasonal streams.^[12] In the Pantanal it occurs in the flooding area of the Paraguay River, Nabileque, Abobral and Poconé.^[4] In the Bolivian Pantanal, Nymphaea oxypetala was observed growing at depths of up to 2 m in gaps amid mats of floating vegetation and in localities where human activities prevented the growth of such floating mats along the margins.^[3]

The type specimen was collected by W. Jameson in March 1845 in Ecuador near Guayaquil.^[6][9]

It is placed within Nymphaea subg. Hydrocallis.^[13]

The specific epithet oxypetala refers to the pointed petals of this species.^[4]