Dark blackish-green plant with submerged leaves only, with a few very long parallel segments, collapsing out of water. Flowers white, large 20 to 30 mm petals overlapping.

Indicator Species - Leicestershire, Leicester & Rutland Local Nature Recovery Strategy.

Other crowfoots, especially R penicillatus subsp. pseudofluitans

Ref. key in Stace.  The differences between species in this difficult subgenus are hard to tell from a photo.  Details of the flower petals and nectaries, and of the two types of leaf, are needed.  Capillary leaves are thread like, usually but not always submerged; and laminar are 'normal', usually floating or terrestrial, but not always.

Photograph: in habitat, of both kinds of leaf, and a close-up of flower.  Take a specimen, including both types of leaf, if present, and retain it until your record is verified; you may need to send the specimen to the County Recorder.  An explanation of how it fits the key in Stace is needed.

Fast flowing fresh water, rivers and streams.

June to August.

Perennial.

Found from southern Scotland southwards, but rare in Wales and south-western England.

Occasional in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 23 of the 617 tetrads.

It is listed as Native and Frequent in west, rare or absent elsewhere, in the current VC55 Checklist (Jeeves, 2011)