Sage and the Bee

I am not sure what kind of native sage this is, I planted it years ago in a mixed bed outside the dining room window in SJC. It is kind of woody and blooms all year round with soft, hazy gray-green foliage. The unique thing about this plant is that it attracts a specific kind of bee. I don't know much about bees and I don't know what kind of bee it is, but at all times there is one, single, big fat black bee buzzing this plant. The bee moves from stem to stem, flower to flower, gathering pollen and then takes off. He returns in a few minutes to continue this quest. Now I am sure that it could possibly be more than one bee that loves this plant, but you only see one bee at a time, all the time. I never see that bee at any other plant, or in fact, anywhere else in the garden except on this sage. Truly a match made in heaven!