Plant of the Week: Grass of Parnassus: Parnssia spp.

I have no earthly idea how this plant got its name because neither the leaves nor flowers look anything like a grass.  One source indicated that early botanists thought this was the species in Greece that was described as the grass on Mount Parnassus in Materia Medica by the famed botanist Dioscorides.  It also goes by the name of bog star and that is perhaps a better common name. However it got its name, it is one showy member of the saxifrage family that brightens up the fall bog garden or wet seeps.  Several species, P. glauca and P. grandifolia like calcareous sites whereas P. asarifolia likes acidic sites. These are the three primary species found in the eastern United States and as you might expect since they are bog plants, the other species found in North America occur much further north.  The two species that occur in Kentucky, P. grandifolia and P. asarifolia are both quite rare and these species are not typically found in the nursery trade.  However, P. glauca, is widely available and will do very well in Kentucky because it is found close to Kentucky's northern and eastern borders. The reason it is not uncommon in the trade is because it is easily propagated from division shortly after the flowers have died and it transplants well.  This lovely species likes partial shade, not full sun or dense shade, and of course continuously wet or moist soil, usually growing out of sphagnum moss.  Calcareous soils are a must for this species and it sprouts a 1" wide flower on top of a 12" tall stem, so it is a rather short growing species in the garden. It has stiff, leathery leaves that occur at the base of the plant and are somewhat heart shaped. In Kentucky it flowers in mid-September through October and a great companion plant is the greater fringed gentian (Gentianopsis crinita) which flowers at the same time and is about the same height. Another option would be Elliott's gentian (Gentiana catesbaei) which has more individual flowers and is a lighter blue color instead of the deep blue of the fringed gentian.