This member of the Hydrocharitaceae family is my
favourite among aquatic/floating plants. It rarely flowers in
Denmark, but in 2013, I was lucky to find it in full flowering in
centimetres over water, 3-5 below.
Pontederia dubia, Carl Ludwig von Blume 1827.
Blume Hydrocharis dubia, Cornelis Andries Backer
It was given this name
by Carl Linnaeus in 1752, and it is spread around Europe and near
Asia. The leaves will lie on the surface of the slightly acid and
nutrition poor water. Each leave can grow to four centimetres in
diameter, each plant will have four to eight leaves. Besides from
the seeds, it sets offspring which sink to the bottom in winter.