Early Autumn is here, a combination of warm sunny days and some rain.

We’ve taken the advantage of recent drier weather to do more trips, including visits to Beeston Common, near Sheringham, in North Norfolk. It’s an hour’s train ride from Norwich and its valley mire is the home of some lovely plants, including Grass of Parnassus.

Grass of Parnassus, Parnassia palustris, is one of the treats of autumn. It grows in wet places, such as base-rich flushes in bogs, short grassland and valley mires. In the British Isles it has a mostly northerly distribution, though that is due to the lack of habitat further south, especially as land has been drained and “improved”. It grows near sea level (var ‘Condensata’) on the machair of western Scotland and in Lancastrian and Cumbrian dune slacks, but also up to 1000 metres (3000 feet) on mountains, such as Ben Lawers in Perthshire. Further afield, it occurs in northern parts of continental Europe, northern and central Asia, North America and parts of North Africa.

Parnassia palustris isn’t really a grass (family Poaceae), but a member of the Celastraceae, the Staff-vine family. Most members of this family grow in the tropics but Spindle (Euonymous europeaus), which I wrote about in October 2012, is in also in this family. (As we learn more about relationships between plants, they are sometimes reclassified into different families. When I did Botany at university, Parnassia palustris was considered to be a member of its own family, the Parnassiaceae, and before that it was considered to be a member of the Saxifragaceae.)

Grass of Parnassus is a perennial plant and early in the summer you’ll only find its basal leaves. But from July or August (sometimes even late June) the plant will produce exquisite white buds atop flower stalks, which grow from 10 to 30 centimetres tall. The flowers open in late summer to early autumn, over several weeks. They are beautiful and very memorable: each flower has five white petals, with strong, translucent grey-green veins. On a still, warm day the flowers have a very delicate, honey scent.

Each flower is hermaphrodite, that is, it has both male and female reproductive parts. At the centre of the flower are the female parts: the pistil, made up of four fused carpels, with a very short style branching into four stigmas. These are surrounded by five three-pronged sterile stamens. Each of these is tipped with drop-like, false nectaries, which (along with veins on the petals) help to attract pollinating flies and bees.

The Finnish NatureGate website describes how the plant produces its nectar to attract pollinating insects. The Wildflower Finder website has a series of excellent photographs showing the flowers and the development of seedheads. The seeds are easily spread by wind and water. They are small and light (30 micrograms each) and have an air-filled pouch that helps them to float.

With its exquisite flowers,Grass of Parnassus has inspired poetry. Andrew Lang (1844 – 1912), writing of the plant in Galloway in southern Scotland, referred to the plant’s “returning snow / Between September and October chill” in his poem “Grass of Parnassus“. Plantlife describe it as “A flower of cold beauty and a symbol of ‘the wilderness and wet'” and NatureGate’s description of the plant’s habitat is very lyrical: “Grass of Parnassus grows where cool air flows in low peatland meadows and wetlands which get easily misty and catch the first night frosts.”

Parnassia palustris is the county flower of both Cumbria and Sutherland, and appears on the Cumberland flag.

One of the alternative names for the plant is ‘Bog-star‘, which is nicely descriptive. (Sometimes this is written as ‘Bog star‘.) The plant’s Latin name, Parnassia, was coined by Linnaeus. This and the ‘Parnassus’ in the English name both refer to Mount Parnassus in Greece. In ‘Flora Britannica‘, Richard Mabey traces the name Grass of Parnassus back to 1576 when the Flemish botanist Matthias de l’Obel* used the name ‘Gramen Parnassi’, which Henry Lyte translated into English in 1578.

The First Nature website suggests why ‘Grass’ is part of the name: it could be because the veins on the petals resemble grass leaves or because cattle on Mount Parnassus enjoyed eating the plant as if it were a grass. More certain and very apt is that ‘palustris‘ refers to the wetlands where the plant can be found.

Grass of Parnassus is not noted for being edible, though the Plants for a Future website describes some of its possible medicinal uses.

I leave you with another photograph of this exquisite plant, and a tip for photographers: take your photographs on an overcast day or shade the flowers. Bright sunshine bounces off the white petals and photographs will be bleached out. Oh, and wear boots or even wellies.

Photograph by Vanna Bartlett.

*The genus Lobelia is named after him.