Common Ivy (Hederae helix) is the last wild flower of the year to flower en masse. And there's a lot of it! Not to mention Atlantic Ivy (Hederae hibernica) in the west and Ireland. Actually Gorse is also autumn flowering but not as ubiquitous as Ivy. 

 As such Ivy is a great source of pollen and nectar for the gamut of pollinators still on the wing: bees, butterflies, wasps, flies, hover flies et al.