WASHINGTON/LOS ANGELES, Feb 7: The medical marijuana shop next to a tattoo parlor on a busy street in Los Angeles looks much like hundreds of other pot dispensaries that dot the city. Except for one thing: On the glass door – under a green cross signaling that cannabis can be bought there for medical purposes – is a sticker for the United Food and Commercial Workers union (UFCW), the nation’s largest retail union. (agencies)