Common Water Crowfoot Taken at Vane Farm on 14th June 2009 using Nikon D40X with Nikon 300 mm zoom lens.   Common Water Crowfoot. Species: Order: Family: Habit: AKA: Ranunculus aquatilis. Ranunculales. Ranunculaceae. Aquatic. Habitat: Blooms: Height: Feature: Fresh water ponds May-September 10 - 30 mm All Ranunculus species are poisonous when eaten by livestock, but their acrid taste and the blistering of the mouth caused by their poison means they are usually left uneaten. Symptoms include bloody diarrhoea, excessive salivation, colic, and severe blistering of the mucous membranes and gastrointestinal tract.