Category Archives: South Gloucestershire

Beautiful Demoiselles

Vic Savery sent me these excellent photos of Beautiful Demoiselle (Calopteryx virgo), which he took at Three Brooks Nature Reserve in Bradley Stoke yesterday. Demoiselles are our largest damselflies, and one of our most noticable and easily-recognised, and like the Common Clubtail I featured in an earlier post, mainly river-dwelling species.

 female demoiselle1  beautiful demoiselle1
Beautiful Demoiselle, 14 June 2013, Bradley Stoke, Bristol, Vic Savery (naturenutz.net)

There are two species of demoiselle in Britain; Banded Demoiselle (Calopteryx splendens), the other species, has a narrow dark patch across the wings in males, with extensive clear areas at both the base and tip, and has a blue rather then blue-green abdomen. Female Bandeds are more similar in appearance to female Beautiful Demoiselle, but with green-tinged rather than brown wings. There are other species of demoiselle in continental Europe, including the Copper Demoiselle (Calopteryx haemorrhoidalis) with a copper-red abdomen.

Beautiful Demoiselle prefers faster-flowing streams with stony riverbeds, whereas Banded likes slower-flowing muddier-bottomed rivers; however the two are often found together, indicating some overlap in the types of river they prefer. Ther British distributions differ: Beautiful Demoiselle is mainly found in Wales, southern and western England, with an outpost in western Scotland, whereas Banded Demoiselle is found throughout England and Wales but only just makes it into southern Scotland.

Around Bristol, both species are found on many of our rivers and streams, including the Avon, Chew, Cam, Wellow, Yeo, and both the Bristol and Bath River Fromes. They are also often found away from rivers (e.g. around ditches on the North Somerset levels, or at ponds and lakes throughout the region).

Bird’s-nest Orchids in Lower Woods

Vic Savery kindly sent me this excellent photo of a Bird’s-nest Orchid (Neottia nidus-avis), one of a group of six he found today in Lower Woods, near Wickwar. The plants were in either Gibbons Trench or Horwood Trench, two paths which run west from the main north-south ride (see the reserve map here). Bird’s-nest Orchid is found in several scattered woodland sites around Bristol, usually in small colonies like the one Vic found today. The situation is much the same in Somerset and Wiltshire, but it becomes more common in the Cotswolds, the Forest of Dean and the Wye Valley.

birds nest orchid 9
Bird’s-nest Orchid, 27 May 2013, Lower Woods, Gloucestershire, Vic Savery (naturenutz.net)

Bird’s-nest Orchid obtains its nutrients from a species of Sebacina fungus, which lives in the root system of the orchid and in turn receives its nutrients from nearby tree roots, The relationship between the fungus and tree is a two-way partnership: the fungus passes minerals back to the tree. The orchid however, gets a nutritional free ride. In many sites, the host tree is Beech (Fagus sylvatica), although in Lower Woods, it is presumably Hazel (Corylus avellana). Anyway, because of all this, Bird’s-nest Orchid doesn’t need any of the green photosynthetic chlorophyll molecule, hence its characterstic pale brown colour. No other similar-looking British woodland plant species is at its flowering peak at this time of year: Toothwort (Lathraea squamaria) is well past its best, and Yellow Bird’s-nest (Monotropa hypopitys) is still underground.

For more of Vic’s photos, take a look at his website.

Toothwort at Lower Kilcott

Toothwort-blog-1

Photographed this afternoon in a sunken lane along a stretch of the Cotswold Way at Lower Kilcott, northeast of Chipping Sodbury.

Toothwort (Lathraea squamaria) is a root-parasite of various trees and shrubs; often Hazel, but also Beech and Alder. It’s a native species in Britain, found throughout England (except for Cornwall and Norfolk), and also in eastern Wales and southern Scotland. There are many populations in woodlands throughout the Cotswolds (last weekend, we saw lots in the woods along the entrance road to Chedworth Roman Villa). Closer to home, it’s present in the Golden Valley at Wick, and in the Leigh Woods/Avon Gorge area, among other places.

Toothwort-blog-2

At Lower Kilcott, we counted 85 flowering stems in four separate colonies. The largest of these contained 59 flowering stems, and a portion of this is shown in the photo above. The green arrow on the Google map below shows its location.

There are six other species of toothwort worldwide, and one of these, Purple Toothwort (L. clandestina) is naturalised in scattered localities throughout Britain, including a few places locally.