Quite common are northern bur-reed Sparganium hyperboreum, small pondweed Potamogeton pusillus ssp. groenlandicus, dwarf water-crowfoot Ranunculus confervoides and occasionally awlwort Subularia aquatica, which only blooms if the pond is totally desiccated (where the mudworm Limosella aquatica also thrives).    From Wordnik.com.  [Ilulissat Icefjord, Denmark-Greenland] Reference