cannabis

California says revenue from marijuana sales has risen — but analysts say the illegal market is still thriving. Here, an employee puts down an eighth of marijuana after letting a customer smell it at the Magnolia cannabis lounge in Oakland. Elijah Nouvelage/Reuters hide caption

Scientists exhumed 10 wooden braziers from eight tombs at the ancient Jirzankal Cemetery in what is now western China. Many of the braziers held stones that were apparently heated and used to burn cannabis plants. Xinhua Wu/Science Advances hide caption

A bipartisan group of attorneys general is urging Congress to pass legislation that would make it easier for banks to handle money involved in the legal cannabis industry. Brennan Linsley/AP hide caption

Cannabis: The Illegalization of Weed in America, by Box Brown First Second hide caption

Research shows a link between marijuana use and psychosis. Kirill Vasikev/EyeEm/Getty Images hide caption

The rain didn't stop customers from lining up outside Cultivate in Leicester, Mass., on Tuesday — the first day that sales of recreational marijuana became legal in the state. Steven Senne/AP hide caption

Even a week without marijuana use improves young people's ability to learn and remember. BURGER/Canopy/Getty Images hide caption

Baby boomers who use marijuana seem to be using it more often than in previous years, a recent survey finds — 5.7 percent of respondents ages 50 to 64 said they'd tried it in the past month. The drug is also gaining popularity among people in their 70s and 80s. Manonallard/Getty Images hide caption

Canopy Growth Corp., the parent company of Corona beer and other alcoholic drinks, is expanding its partnership with a Canadian pot producer, betting on the continued growth in the medical and recreational cannabis markets. Richard Drew/AP hide caption