Aquatic. Inflorescence erect, up to 40 cm long; Ovary globose, style distinct, about as long as ovary, stigma lower lip semi-orbicular, margin denticulate, upper lip very short. Capsule and seeds not known.
Asia-Temperate, Asia-Tropical: India present; Jawa (Jawa present); New Guinea present; Philippines (Philippines present); Sumatera (Sumatera present), Ceylon present, Japan present, SE. Australia present, W. Europe present, tropical and S. Africa present
W. Europe to China and Japan, tropical and S. Africa, India (south to Ceylon) to SE. Australia; in Malesia: Sumatra, Java, Philippines, and New Guinea.
This widespread temperate Eurasian species apparently never sets seed and its somewhat sporadic occurrence, mostly at high altitude, in the African and Asian tropics is probably due to transmission of small particles of its vegetative parts by migrating birds. It has been much con- fused with U. aurea but is easily distinguished by its 1 or 2 (not 3 or more) primary foliar segments without basal stipule-like segments and when in flower by the presence of scales on the peduncle.