SANTA CRUZ, Calif. — Some of the local growers along the coast here see it as an act of medical compassion: Donating part of their crop of high-potency medical marijuana to ailing veterans, who line up by the dozens each month in the echoing auditorium of the city’s old veterans’ hall to get a ticket they can exchange for a free bag.

One Vietnam veteran in the line said he was using marijuana-infused oil to treat pancreatic cancer. Another said that smoking cannabis eased the pain from a recent hip replacement better than prescription pills did. Several said that a few puffs temper the anxiety and nightmares of post-traumatic stress disorder.

“I never touched the stuff in Vietnam,” said William Horne, 76, a retired firefighter. “It was only a few years ago I realized how useful it could be.”

The monthly giveaway bags often contain marijuana lotions, pills, candies and hemp oils, as well as potent strains of smokable flower with names like Combat Cookies and Kosher Kush. But the veterans do not get any medical guidance on which product might help with which ailment, how much to use, or how marijuana might interact with other medications.