The main colour is black but it has golden to brown hairs which cover the face and thorax becoming sparser and paler on the abdomen.

[4] Osmia xanthomelana is found around eroded cliffs of softer rocks such as clay and chalk, among landslips, dunes and in semi-natural and unimproved grassland where its food plant bird's-foot trefoil occurs.

The nests are usually dug out in south-east facing eroded banks, occasionally burrows from previous seasons are reused after being cleaned out by the female.

The females collect freshwater from seepages around the base of the cliff to make mud which is then combined with grit to the construct the nest cells.

The cells are provisioned with pollen from bird's-foot trefoil although O. xanthomelana will nectar on a variety of plants such as horseshoe vetch, bramble and bugle.