Askham Bog

Slender tufted sedge, Carex acuta
Slender tufted sedge, Carex acuta

longhorn moth green veined white11 a.m.: Orange tips and green veined white butterflies are attracted to the flowers of jack-by-the-hedge which grows in swathes along the edge of the swampy woodland at Askham Bog Yorkshire Wildlife Trust reserve, southwest of York.

Its white flowers have also attracted a longhorn moth Adela reaumurella, a metallic green micro moth, less than a centimetre in length. My photograph shows a female; the male’s antennae are twice as long, three times the length of its forewing.


Slender tufted sedge, Carex acuta (above), has sharp corners on its triangular stems. In my photograph, the male flower spikes are the dangling ochre tassels while the female spikes, below them in the flower head, have two styles growing from each ovary, like the forked tongue of a serpent.

Askham Bog has the largest colony of gingerbread sedge, Carex elongata, in England. In autumn the floppy tussocks of this sedge and its spikes of seeds turn reddish brown. Is that how it gets its name? Is it the colour of gingerbread? Or did it once have some use as a food or herbal remedy?

The colony is in Far Wood, east of the reserve’s boardwalk so wellies are recommended if you go in search of the sedge.

Water Plants

amphibious bistort

water violet

The pink flowers of amphibious bistort, Persicaria amphibium (above), are still in bud. It’s floating leaves are pointed at the tip and blunt at the base.

Despite its name water violet, Hottonia palustris, is a relative of the primrose. In my photograph you can see the stigma of the flower in the yellow centre of the foreground flower. In primroses this is what botanists refer to as ‘pin eyed’. Water violet has finely divided fern-like leaves beneath the surface of the water.


Dog violet
Dog violet
Marsh violet
Marsh violet

Dog violets grow alongside the duckboards and a few marsh violets, Viola palustris, which have paler flowers with dark veins. Marsh violet has long creeping rhizomes so when we spotted one, we soon found a few more scattered around nearby amongst the marsh plants.

Royal Fern

royal fernRoyal fern, Osmunda regalis, is just starting to unfurls its fronds. This is one of the tallest of European ferns, growing to several metres.


Askham Bog Yorkshire Wildlife Trust Reserve.

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