Potteric Carr near Doncaster

Saturday 2nd September 2023

Leader: Louise Hill

This was a joint meeting with the South West Yorkshire Botany Group. The last time BBG visited this Yorkshire Wildlife Trust Reserve was in 2007, so a return visit was long overdue. We were again fortunate in having dry and sunny weather, even becoming a little too hot. After paying the £5 entrance fee at the visitor centre (or showing our Wildlife Trust memberhip cards), Louise gave a short introduction and explained the intended route, using a large wall map located in the outdoor seating area. We had been given special permission to visit a part of the site not usually accessible to the public, where the birds had now finished breeding.

After a short walk, during which we passed good numbers of the cheerful yellow flowers of Common Fleabane (Pulicaria dysenterica), we walked the perimeter of a large pond where there were numberous dragonflies and damselflies, including common darters, which were busy egg laying. In the water was Fen Pondweed (Potamogeton coloratus) and Louise explained some of the id features. The leaf stalk has a kink, as in Broad-leaved Pondweed, but in Fen Pondweed, all lvs are below the water surface. Growing close by was Common Spike-rush (Eleocharis palustris) and Grey Club-rush (Schoenoplectus tabernaemontani). In the rough grassland surrounding the pond, plants included Imperforate St John's-wort (Hypericum maculatum), Yellow Loosestrife (Lysimachia vulgaris) and Common Hemp-nettle (Galeopsis tetrahit).

At this point it became clear to me that insect repellent would have been a good idea, as I ineffectively swiped away successive biting mosquitos. The interesting array of plants however stole my attention. Back at the water’s edge on the other side of the pond were Purple-loosestrife (Lythrum salicaria), Blunt-flowered Rush (Juncus subnodulosus) and the small white flowers of Brookweed (Samolus valerandi).

After applying some bite-cream to my arms, kindly provided by Rita, I caught up with the group, who were moving further into the reserve. A pond-dipping platform alongside one of the many wildlife-rich drainage channels had Ivy-leaved Duckweed (Lemna trisulca) and Broad-leaved Pondweed (Potamogeton natans). Also here was a distant view of Unbranched Bur-reed (Sparganium emersum). A little later, at another channel, was Branched Bur-reed (Sparganium erectum), positioned more conveniently for viewing. Nearby were the purple dotted flowers of the hybrid between Hedge Woundwort and Marsh Woundwort, simply called Hybrid Woundwort (Stachys x ambigua). The crushed leaves of this hybrid have a slightly unpleasant smell, but are not as fiercely harsh smelling as Hedge Woundwort (which has been nicknamed ‘stinky stachys’).

At another viewing platform, we looked directy below into the water where Louise pointed out the feathery leaves of Water-violet (Hottonia palustris). Here too were the floating rosette leaves of Water-soldier (Stratiotes aloides), the arrangement of the long thin spiny-serrate leaves said to resemble the top of a pineapple. Water-soldier is thought to be ‘probably native’ to Eastern England and it is now concidered scarce in the British Isles as a native. However, it is also grown in garden ponds and often escapes, so can be found scattered as a garden escape in other places in the UK.

Further on again, Louise used her trusty homemade grapnel to fish for specimens of water plants and we were shown Fennel Pondweed (Stuckenia pectinata), Nuttall's Waterweed (Elodea nuttallii), and later on, Lesser Pondweed (Potamogeton pusillus). Ploughman's-spikenard (Inula conyzae) was good to see at the side of the track.

We explored a patch of rough grassland where plants of Devil's-bit Scabious (Succisa pratensis) were spread throughout, not yet in full flower, but showing the pretty heads of tightly-packed purple flower buds. A single plant of Purple Moor-grass (Molinia caerulea) looked rather spectacular in flower, standing tall amongst the rest of the low vegetation. Also here was Greater Bird's-foot-trefoil (Lotus pedunculatus), Bifid Hemp-nettle (Galeopsis bifida) and a hawkweed named as Hieracium umbellatum. Moving on, we came across Velvet Bent (Agrostis canina), the tufts of fine long leaves produced at intervals along its stolons (stems running above ground like in strawberry).

The grand finale of our visit today was though a gate into a part of the reserve not usually open to the public. The star plants here were Golden Dock (Rumex maritimus) and Bladderwort (Utricularia australis), both of which are uncommon plants in the British Isles and species I’d never seen before. The flowers of the Bladderwort were just out of reach, so we had to use binoculars to view the features that confirmed the identity. A sample of the leafy stems of the Bladderwort was brought out of the water to show the numerous tiny bladders which this carniverous plant uses to trap tiny insects like crustaceans.

Nearby in the grassland was Cyperus Sedge (Carex pseudocyperus) and a mint with flowers in the leaf axils, suspected as being Whorled Mint (Mentha x verticillata). A keen eyed member also spotted Heath Groundsel (Senecio sylvaticus) which we don’t see very often. We then walked the quickest way back towards the cafe for a well earned cuppa or ice cream, spying Black Spleenwort (Asplenium adiantum-nigrum) and the Hawkweed Hieracium vagum on the way. We’d enjoyed an excellent day of botany in the sunshine - I just wish I’d put on some insect repellent at the start of the day!

Text by Susan

Photographs by Nyree, Peter and Susan