“You can’t have a national business,” Mr. Dayton said, because the laws vary by state. Opportunities for small businesses also exist because the stigma associated with the industry has discouraged bigger companies from getting involved. “You can’t find another industry growing at this clip that doesn’t have any major players,” he said. “That gives the little guy a chance to make a run at this.”

That potential has spawned a wide array of cannabis start-ups — many incorporating novel technologies. Potbotics in New York City has raised almost $3 million from friends and family and has three cannabis-related products in the works, including a “virtual budtender” known as Potbot that it expects to be available for sale next year. A budtender is a dispensary worker who is knowledgeable about and sells marijuana; Potbot is a robot with a tablet-size monitor that is meant to replace the budtender.

The plan is to place Potbot robots in dispensaries and medical facilities where marijuana patients can ask questions and get information. “Dispensary budtenders almost always have an agenda — they are trying to sell what they have most in their stock,” said David Goldstein, a founder of the company, which was started in October. “We created a software and technology platform that is able to talk to patients and educate them about what strains are actually best for their ailments.”

A San Diego start-up, Herbalizer, makes a small, sleek vaporizer with a heating system that took three years and two engineers to develop. Its co-founder and chief executive, Josh Young, previously designed advanced NASA computer systems and military programs; Bob Pratt, a co-founder and the chief technology officer, was a designer of stealth bomber radar systems. And yet, Mr. Young said, the technology behind the Herbalizer “has been the greatest challenge of our lives.”

The vaporizer heats up in seconds and uses a 32-megahertz processor, a 300-watt halogen bulb and a temperature sensor to release active compounds in the plant selectively, without creating smoke. Ninety percent of Herbalizer’s customers use it for marijuana, Mr. Young said, although drug paraphernalia laws prevent the device from being marketed for that purpose (it is sold instead for use with herbs like peppermint and lavender). The company expects first-year revenue of more than $2 million.

Image Although the bags are awaiting government approval, Mr. Fortune said he had hundreds of thousands of orders. Credit... David Maxwell for The New York Times

Fund-raising has been tricky for Herbalizer and similar companies. Traditional investors remain leery, said Christian Groh, a partner and the chief operations officer at Privateer Holdings, a private equity firm in Seattle that invests in cannabis start-ups. “In the U.S., marijuana remains a Schedule I narcotic, so you still have this outlaw mentality within the community,” he said. “I know there’s a lot of exuberance now, but I don’t think we’re at the point where we’ll see real institutional money or a Fortune 500 company making a play in this space. Not yet.”