I have to agree with Rich in that I don't see B/W as a genre, but as a secondary categorization (at least I understood his reply in that way). I think I will still post a B/W landscape under the Landscape genre if only one categorization level is allowed/provided.

We do not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs ǝʍ