OAKLAND, Calif.  Jimmy Hoffa would be stoked.

In what cannabis fans were calling a high-water mark for their movement to legitimize the drug, about 100 employees of medical marijuana-related businesses in Oakland were welcomed to the ranks of unionized workers on Friday after voting to join the United Food and Commercial Workers, Local 5.

The move  which union officials said was the first time medical marijuana employees had been so represented  was hailed by the local’s leadership, who called their new members ‘great workers.”

“This is a natural for us,” said Ron Lind, the president of Local 5, whose 26,000 other members work primarily in groceries and the meat industry. “Our union’s primary jurisdiction is retail.”

The move was also welcomed by Richard Lee, the founder of Oaksterdam University, the medical marijuana trade school whose Oakland campus employs some 60 newly unionized members in its dispensary, gift shop and nursery. (For plants, not children.) Mr. Lee that said his employees were already offered health benefits and paid vacation, but that the union imprimatur was an important milestone in the battle to bring marijuana more into the mainstream.