2005 Monmouth 6th September One Day Meeting
The Monmouth meeting under the informed leadership of Heather Colls had a riparian theme as we explored river banks on both sides of the English/Welsh border. Six members met the leader near Dixton churchyard for a gentle walk upstream along the right bank of our first river, the Wye (Afon Gwy). Here the very plentiful Impatiens glandulifera (Himalayan balsam) did not out-compete other species. Tanacetum vulgare (tansy) and Mentha suaveolens (round-leaved mint) were flowering well, the latter recognised by its roundish leaves with the teeth bent under to appear blunt. Patches of yellow here and there indicated a second flush of flowers on Brassica nigra (black mustard) and Raphanus raphanistrum ssp. raphanistrum (wild radish) each with their characteristic fruits. In the shallow water of the river's margin we spotted several dozen flowering stems of Butomus umbellatus (flowering rush).
At a point where we could actually get down to the water's edge we found Mentha x verticillata (whorled mint), Myosoton aquaticum (water chickweed) and Achillea ptarmica (sneezewort) on the bank and Elodea canadensis (Canadian waterweed) and Potamogeton perfoliatus (perfoliate pondweed) in the water. Ranunculus fluitans (river water-crowfoot) grows here in quantity and Heather described to us how the surface of the water is turned white when the plant is in flower. Retracing our footsteps we stopped to admire a splendid many-trunked Tilia cordata (small-leaved lime) growing out of the churchyard wall and spotted Ceterach officinarum (rustyback) growing on the wall on the other side of the lane.
For lunch we crossed the river and moved downstream to Redbrook in Gloucestershire. Here recently disturbed waste ground by the car park yielded Chaenorhinum minus (small toadflax) which Heather suggested had originally come from the ballast of the long-abandoned railway line. Nicotiana x sanderae, Oxalis stricta (upright yellow-sorrel) and Coronopus didymus (lesser swine-cress) and other ruderals were also seen.
In Cadora Woods, still in Gloucestershire, we were shown two of the special plants of the southern Marches: Campanula patula (spreading bellflower) and Euphorbia serrulata (upright spurge but known locally as Tintern spurge from the place of its first discovery in Britain further downstream). Both plants seem to favour relatively bare disturbed ground, in this location provided by the construction of a substantial forestry road.
Back in Wales near the R. Monnow (A. Mynwy) at Overmonnow, Heather showed us a great mass of flowering Securigera varia (crown vetch) several metres square.
Stop number five was near Jingle Street, Wonastow where erosion by the R. Trothy (A. Trodi) and subsequent repair work to protect the adjacent road had disturbed dormant seed of several arable weeds, notably Kickxia spuria (round-leaved fluellen), K. elatine (sharp-leaved fluellen) and Ranunculus sardous (hairy buttercup). From here a wander along the river bank turned up a couple of plants of Dipsacus pilosus(small teasel) which still had a few late flowers.
Our final stop was for tea and cake in Heather's garden where we could enjoy her view of the Monmouthshire countryside and thank her for showing us some of the characteristic plants of the area.
JOHN SWINDELLS