You can buy this beard in the Crown Store. I am pretty sure it is part of the Adornment Cosmetic Pack. it costs about 1,000 crowns.
I bought the long patriarch beard, but was horrified by how scruffy it looked when I put it on one of my characters. It looks like it has never ever been trimmed, washed, combed or oiled! In fact, it looks like the sort of beard that has an eco system of its very own. Suitable only for a Nord I think, and I have no Nords.