SAN FRANCISCO — Reflecting a budding area of law, a group of Bay Area attorneys Wednesday launched the Cannabis Bar Association, the nation’s first professional body to specialize in helping businesses navigate complex marijuana regulations rather than in defending drug cases.

The group is a sign of what cannabis activists call the “Green Rush,” a twist on the term “Gold Rush,” referring to the burgeoning, quasi-legal pot industry.

“As the industry goes from being verboten to being taxed and regulated as commerce, the lawyers like these come with that,” said Allen St. Pierre, executive director of NORML, the National Organization for the Reform of Marijuana Laws.

While federal law still forbids the sale, cultivation, transportation or possession of marijuana, California and 22 other states allow its medicinal use. Recreational marijuana now is legal in Colorado, Washington, Alaska and Washington, D.C., and come July, Oregon.

Many cities, including San Jose, have established local regulations and taxes for marijuana businesses.

And that means the need for legal advice is growing like a weed. California now is home to companies that range from Kiva, which sells cannabis-infused chocolates, to services like The Goddess Delivers, which ships cannabis-extract capsules. Bigger firms are hoping to cash in on the trend, including Silicon Valley-based Mentor Capital, named by Forbes last year as one of the eight hottest publicly traded marijuana companies in the country.

One of the founders of the National Cannabis Bar Association, San Francisco-based intellectual property lawyer Shabnam Malek, said there is a big demand for quality legal advice in the cannabis industry, including how to form a company, negotiate agreements, complete license applications and comply with local and state laws.

For instance, it is illegal to transport cannabis across state lines, so companies who are looking to expand need help finding trustworthy partners in other states, she said. The organization will also serve as an educational and organizational resource for lawyers.

“As more and more states decriminalize or legalize cannabis — and set up their own regulatory structures — the legal conditions cannabis industry clients and their attorneys face are likely to get even more complex before they get simpler,” Malek said. “The NCBA will offer support and advocacy for attorneys working with businesses in this rapidly changing, swiftly emerging industry.”

Lawyers have always been among the biggest advocates of pot decriminalization — to the point where NORML, which was founded in 1970 by criminal defense lawyers who supported fairer pot laws, used to be referred to sarcastically as the National Organization of Rich Marijuana Lawyers, St. Pierre said.

Until fairly recently, however, many lawyers were reluctant to get involved in pot law for fear of running afoul of federal law. Some established bar associations, including Maine’s, have warned lawyers that they may not be immune from legal problems if the advice they offer cannabis clients leads them to break the law. But many associations, including in California, have established cannabis-law subsections.

But as support for legalization has spread, several law schools across the nation now offer seminars on pot law, including the University of Denver. Harvard even had a guest lecturer give a tax planning seminar specifically for marijuana dealers in 2013.

In California, advocates have signaled they plan to put an initiative on the November 2016 ballot to legalize recreational marijuana for adults 21 and older. A similar statewide initiative, Proposition 19, lost in 2010, with 53.5 percent of voters opposed.

The new bar association is positioned to ride the wave.

“Even lawyers from white-shoe firms are starting to set up pot practices,” said Keith Stroup, NORML’s founder, referring to long-established, often-conservative firms with wealthy clientele. “The need is only going to grow.”

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com @tkaplanreport.