In flower on Boxing Day. Common Gorse (Ulex europeus) has a long flowering season -typically January to June- but this is a bit early. Hard to imagine that this viciously spiky plant was widely used as a fodder crop for cattle and horses albeit crushed/mashed. 

 Roy Vickery's excellent Plant-Lore website includes a photo of a Gorse mill built in 1842 in Wales complete with water wheel. He notes that factory-made milling machines became available in the 1850s which were hand-operated or oil powered. Seems like Gorse is a renewable resource which has been largely forgotten.