E.pinnatum colchicum x E.grandiflorum.
Raised in Ghent Botanic Gardens by A.Donckelaar and named in 1854. A vigorous, deciduous hybrid. Very like E.x versicolor 'Versicolor' which had been named five years earlier, from the same breeder.
The red colour fades out of the older flowers until they are nearly (but not quite) yellow. This one also seems to be slightly more deciduous than 'Versicolor'.