Customers lined up early to purchase recreational marijuana legally for the first time in California.
New Year's Day brought broad legalisation some two decades after the state was the first to allow pot for medical use.
America's most populous state joins a growing list of other states, and the nation's capital, where so-called recreational marijuana is permitted even though the federal government continues to classify pot as a controlled substance, like heroin and LSD.
Customers check out cannabis samples on display while waiting in line at the Harborside cannabis dispensary in Oakland, California, USA (AAP) Source: AAP
Jeff Deakin, 66, his wife Mary waited all night and were first in a line of 100 people when Harbourside dispensary, a longtime medical pot shop in Oakland, opened at 6am and offered early customers joints for a penny and free T-shirts that read "Flower to the People - Cannabis for All."
"It's been so long since others and myself could walk into a place where you could feel safe and secure and be able to get something that was good without having to go to the back alley," Deakin said.
California voters in 2016 made it legal for adults 21 and older to grow, possess and use limited quantities of marijuana, but it wasn't legal to sell it for recreational purposes until Monday.
Adults can also grow up to six marijuana plants per household "out of public view."
Only about 90 businesses received state licenses to open on New Year's Day, concentrated in San Diego, Santa Cruz, the San Francisco Bay Area and the Palm Springs area.
Los Angeles and San Francisco are among the State's many cities where recreational pot will not be available right away because local regulations were not approved in time to start issuing city licenses needed to get state permits.
Meanwhile, Fresno, Bakersfield and Riverside are among the communities that have adopted laws forbidding recreational marijuana sales.