Caloscypha fulgens --- no common name. Found by Stephanie Thomas on March 11th in Pembrey Forest (SN 388 020). There are just 21 collections on FRDBI records and is a RDL species. So a great find. This is a quite distinctive 'cup-fingus' from the shade of yellow which turns greenish with age and on handling.
Stephanie also took a habitat photo which is very useful as this shows Birch at the side of a path. The main tree in the forest is Pine (var maritima). As there are so few records, books give a variety of associated trees/shrubs.
In 'Fungi of Switz' 1(plate 97) they say Otto Baral (one of the foremost European mycologists) considers it as mycorrhyzal with Abies (Silver Fir)--- but this was 1981!
Colin has done microscopy --- below ---- which shows the round spores and that the ascus tip is not blue in iodine stain -- Meltzers iodine --- and, last picture there is one of the 'paraphyses' and these ar 'Y'-shaped.