Miles, P. M. 1978. Blomer's Rivulet, Discoloxia blomeri (Curtis) (Lepidoptera, Geometridae) and Dutch Elm Disease, Ceratocystis ulmi Buism. Entomologist's Gazette 29,43-46. Philip M. Miles, Werndeg, Cnwch Coch, near Aberystwyth, Dyfed SY23 4LQ The Growth and Survival of Aconitum anglicum (Monkshood) at Gwern Rhyd Nature Reserve, South Glamorgan The Gwern Rhyd Nature Reserve (ST. 099769) is situated in the community of St George's Super Ely with St Brides. It is bounded by the river and railway on its southern flank, by the lane linking St George's and St Brides to the east and by the bridlepath to Peterston Super Ely to the north. The western extremity coincides with the edge of the woodland. The reserve is at the centre of the Ely Valley SSSI whose main feature is the occurrence of the Monkshood (Aconitum anglicum). Site Description For the most part the Reserve consists of damp woodland, the most common species being Alder (Alnus glutinosa). Other tree species include Oak (Quercus pedunculata), Ash (Fraxinus excelsior), European Larch (Larix europaea), Sycamore (Acer pseudoplatanus), Maple (Acer campestre), Elm (Ulmus sp.), Holly (Ilex aquifolium). Small trees and shrubs include Dogwood (Cornus sanguinea), Spindle (Euonymus europaea), Wild current (Ribes sp.), Hazel (Coryllus avellana), Elder (Sambucus nigra), Blackthorn (Prunus spinosa), Crab (Malus pumila), Hawthorn (Crataegus monogyna). The herbaceous layer includes Mercury (Mercurialis perennis), Yellow archangel (Galeobdolon luteum), Ivy (Hedera helix), Jewel weed (Impatiens capensis), Himalayan Balsam (Impatiens glandulifera), Hemlock water dropwort (Oenanthe crocata), Monkshood (Aconitum napellus), Flag (Iris pseudacorus), Garlic (Allium ursinum), Golden Saxifrage (Chrysosplenium oppositifolium), and a single plant of Bellflower (Campanula latifolia), was found in 1981. There are two smaller areas within the reserve: (a) Recently coppiced alders; (b) A clearing. Miles, P. M. 1981. Heterocera of Dyfi National Nature Reserve- Y nyslas Dunes, Cardiganshire, Wales, 1974-1978. Entomologist's mon. Mag. 116, (1980) 246-252. R. M. Baker The Aconitum is present in the coppiced area, but absent from the clearing. The clearing is undergoing secondary succession and includes sub-areas dominated by: (a) Reed (Phragmites communis); (b) Blackthorn (Prunus spinosa); (c) Bracken (Pteridium aquifolium); (d) Bramble (Rubus fruticosa agg.); (e) Mixed wetland vegetation (Iris pseudacorus), Meadowsweet (Filipendula ulmaria), Balsam (Impatiens glandulifera), Codlins and Cream (Epilobium hirsutum); (f) Coarse grasses. Numerous trees and bushes of the following species have been planted into the clearing: sycamore (Acer pseudoplananus) in 1975, and in 1981, Hornbeam (Carpinus betulus), Guelder Rose (Viburnum opulus), Spindle (Euonymus europaea), Lime (Tilia platyphylla), and Maple (Acer campestra). The clearing also includes self sown Sallows (Salix atrocinerea), and an overgrown hedge. There is an Osier (Salix viminalis) on the river bank. That the area represents semi-natural as opposed to truly natural woodland is shown by the presence of a few individual Larch (Larix europaea) in the woodland, and a Lilac (Syringa vulgaris); in the hedge flanking the Bridlepath. Soils and drainage. The whole area is underlain by glacio-fluvial deposits, in this case the stony, pebbly phase being most common. However, in most parts of the reserve these deposits are overlain with silty peats which are highly retentive of moisture. Adjacent to the river are natural sand levees. The water table is high on the peaty areas even after weeks of drought and the streams in the reserve did not dry up even in the droughts of 1976 and 1984. The pH readings are in the range of 6.5-7.0.