Parnassia grandifolia, also known as bigleaf grass of Parnassus,[2] is a flowering herbaceous plant of the family Celastraceae.

[3] Its primary habitat is open wet areas over calcareous soil, such as fens and gravelly seeps.

[2] Parnassia grandifolia is uncommon throughout its range, often having a low number of individuals at a given site.

It is considered an indicator of high quality seepage communities,[4] and does not tolerate habitat degradation.

[1] It is a rosette forming perennial that produces white flowers in late summer and fall.