Parnassia palustris


Grass-of-parnassus, also known as bog star, is a striking plant with creamy-white flowers on tall stems (11-30cm). The flowers have five oval petals with distinctive ‘grass-like’ green veins that run down the petals, surrounding a group of five yellow stamens and five anthers. Flowers can be seen from June-September. The leaves cup the stem around the base and are dark green and heart-shaped.


Grass-of-parnassus is found in damp soils in both acid and calcareous areas such as wet moors, damp pastures, and marshes.

Distribution and threats

Grass-of-parnassus is widely distributed across northern Britain but is only found in localised patches in the south. It is therefore listed as Least Concern in the Red Data Book for Great Britain but listed as Vulnerable in England, with a trend of decline in this species in southern Britain due to land drainage of its preferred habitats. Grass-of-parnassus is locally scarce in Oxfordshire, with only two locations recorded within the county since 2010.