This is a very low-growing plant – only grows to about 20cm tall – which is found mainly in the Burren and County Galway. It is similar to Heath Bedstraw but has more non-flowering shoots. The hairless, oblong leaves – which are in whorls of 5-8 - are also far narrower in this species and are bristle-tipped with backward-pointing margin bristles. They are borne on smooth, 4-angled stems. It bears small (3mm) creamy-white or greenish, 4-petalled flowers in domed clusters. Its preferred habitat is limestone grassland – never acid soil. Occasionally the two species grow side by side but the bristles along its leaf margins clearly identify it from Heath Bedstraw. It is a scarce, native perennial which flowers in June and July and belongs to the Rubiaceae or Bedstraw family.
I first found Limestone Bedstraw and photographed it in the Burren in May, 2010. At first I identified it as Squinancywort, but a kind botanist, Paul Green, put me right on that one. Squinancywort is more of a pink shade than Limestone Bedstraw.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre