Galium uliginosum or fen bedstraw is a plant species of the genus Galium. It is widespread across most of Europe as well as Morocco, Western Siberia, Turkey, Kazakhstan and Xinjiang. It is reportedly naturalized in New Zealand, Greenland and the Crozet Islands.<ref>Kew World Checklist of Selected Plant Families</ref><ref>Altervista Flora Italiana</ref>
Galium uliginosum is a component of purple moor grass and rush pastures – a type of Biodiversity Action Plan habitat in the UK. It occurs on poorly drained neutral and acidic soils of the lowlands and upland fringe. It is found in the South West of England, especially in Devon.<ref>page 60 of Wild Flowers of Britain and Ireland, a photographic guide to over 600 species by Rae Spencer-Jones, Sarah Cuttle, published by Kyle Cathie Limited, 2005</ref>
Galium uliginosum is easily confused with marsh bedstraw, Galium palustre, but is distinguished from this species by having bristly edges on its leaves, and not turning black when it dries out. The leaves are arranged in whorls of 6 to 10 around the stem, which is a characteristic feature of the bedstraw genus Galium.
- Naturegate, Luontoportti, Helsinki, fen bedstraw
- Northern Ireland Priority Species Galium uliginosum
- Tela Botanica, Gaillet aquatique Galium uliginosum
- Wilde Planten in Nederland en Belgie, Ruw walstro, Wrede tongblier, Fen Bedstraw, Gaillet aquatique, Moor-Labkraut
- Besançon, Galium uliginosum Linné Gaillet aquatique