Nuphar oguraensis

Nuphar oguraensis is a species of rhizomatous aquatic plant endemic to Japan.

Vegetative characteristics
The petiolate, green, ovate floating leaves are 7.5-11.5 cm long, and 6-9 cm wide. The petiole is 1-3 mm wide. The petiole is semi-hollow.

Generative characteristics
The flowers are 1.7-2.5 cm wide. The 2.5-3 cm long, and 1.5-2 cm wide fruit bears brown, 3.5-4 mm long, and 2.5 mm wide seeds.

Generative reproduction
Flowering occurs from June to October.

Publication
It was first described by Shigeru Miki in 1934.

Type specimen
The lectotype is an illustration of this species in the original publication by Shigeru Miki.

Natural hybridisation
It has been speculated to be of hybrid origin involving Nuphar pumila and Nuphar japonica.

Conservation
It is threatened by urbanisation and land development. It is regarded as a vulnerable species.

Habitat
It occurs in rivers, lakes, ponds, and ditches.