Nymphaea alba subsp. occidentalis

Nymphaea alba subsp. occidentalis is a subspecies of Nymphaea alba native to western and northern Europe.

Description

Vegetative characteristics

Nymphaea alba subsp. occidentalis is an aquatic, rhizomatous, perennial plant. The relatively small leaf is 9–13 cm long.

Generative characteristics

The relatively small, 5–8 cm wide flowers do not open widely. Stamens are absent towards the upper end of the ovary. The gynoecium consists of 8–15 carpels.

Taxonomy

It was first described as Nymphaea alba var. occidentalis by Carl Hansen Ostenfeld in 1912. It was elevated to the rank of the subspecies Nymphaea alba subsp. occidentalis published by Nils Hylander in 1945. Some sources treat it as a synonym of Nymphaea alba, but others accept it as a subspecies.
Within the subgenus Nymphaea subg. Nymphaea, it is placed in the section Nymphaea sect. Nymphaea.

Etymology

The subspecific epithet occidentalis means western.

Ecology

It occurs in small, nutrient poor aquatic habitats in ponds, marsh pools, small lakes, and sheltered bays of larger lakes.

Distribution

It is native to Belgium, Denmark, Finland, France, the United Kingdom, Ireland, Norway, and Sweden.

Conservation

It is very rare. In Sweden, it is classified as vulnerable. In the United Kingdom, it is of national conservation concern.