You can’t take it with you. Actually, you can. But it’s not a good idea when you’re traveling, especially for the risk-averse.

We speak, of course, of cannabis; its use was approved in California by 57 percent of voters in November 2016. Proposition 64, known as the Adult Use of Marijuana Act, allows the recreational use of marijuana in the Golden State; medical marijuana had been legal for about a decade before that.

Legal, it should be noted, in California. Not legal according to federal law.

Ontario airport recently rolled out a new ad program for trays at security checkpoints. The campaign is for Organa Brands, one of the country’s largest cannabis companies, and alerts travelers that while cannabis is legal in California, they cannot take it across state lines. (Robin Abcarian/Los Angeles Times)

The conflict between state and federal law is at the root of the confusion. To clarify issues about traveling with cannabis, here are some questions and answers to help guide you.

Note that the answers are based on what’s legal now and are offered with the knowledge that there is a bit of “wink, wink, nod, nod” going on. The easiest way to stay within the law is not to break the law, even if you disagree with it.

Note also that this is only for the U.S.

Question: May I have cannabis in my carry-on bag if I’m flying to a state where it’s legal?

Answer: No, not legally, in carry-on or checked baggage, and here’s why, according to the Transportation Security Administration’s explanation on its website: “Possession of marijuana and cannabis infused products, such as Cannabidiol (CBD) oil, is illegal under federal law. TSA officers are required to report any suspected violations of law, including possession of marijuana and cannabis infused products.”

Q: But would they bust me for that?

A: Maybe. TSA’s further explanation: “TSA’s screening procedures are focused on security and are designed to detect potential threats to aviation and passengers. Accordingly, TSA security officers do not search for marijuana or other illegal drugs … ”

But, it notes, if it does find drugs, it will “refer the matter to a law enforcement officer.”

Q: But it’s legal in California, so why would I be in trouble?

A: Because it’s not legal under federal law. You cannot transport cannabis to another state.

It’s especially confusing because California laws allow possession. But, said Jonathan Havens, co-chairman of the cannabis law practice at Saul Ewing Arnstein and Lehr, a firm with offices in numerous states, the issue is crossing (or attempting to cross) state lines with a “federally illegal product.”

“It doesn’t matter if a state has said you can consume it,” Havens said. “When you are crossing state lines … to another state, even if it’s another state that has a law on their books, with a federal illegal product that’s interstate commerce and that’s a problem.”

Unidentified travelers exit the airport past a green metal container designed for “Disposal for Prescription and Recreational Drugs,” set outside one of the entrances to McCarran International Airport in Las Vegas, Thursday, Feb. 22, 2018. (AP Photo/Regina Garcia Cano)

Q: OK, I’m driving to Oregon, where it is legal. Am I OK?

A: No. See above in re: transporting across state lines. Buy it there and use it there; don’t bring it home.

Q: I’m driving to Arizona and I want to take cannabis. I bought it legally in California. Am I OK?

A: No. You must abide by the laws of the state you are in, and it is not legal for recreational use in Arizona. And you also can’t transport it across state lines.

Take a look at Weedmaps’ page or the page from the National Organization for the Reform of Marijuana Laws, each of which has a rundown on state laws.

Q: I have a license for medical marijuana. Can I carry it on a plane if I have all the paperwork?

A: No. Same problem: not legal at the federal level.

Q: I have a medical card in California. Can I use it to buy in the state I’m visiting?

A: Don’t count on it. “People should not assume there is reciprocity,” Havens said.

Q: Aren’t these answers conservative?

A: Yes. But I appreciated what Chris Beals, president and general counsel for Weedmaps, which he describes as the “largest tech company servicing the cannabis space,” told me: You may be complying with state law, but if you’ve run afoul of federal law, “You’re generally not dealing with the state authorities who have put a legal system in place.

“The easiest advice is: Don’t travel with cannabis across state lines. You never know when you’re going to (encounter an authority) who says cannabis prohibition should be the law, regardless.”

© 2018 Los Angeles Times. Visit Los Angeles Times at Distributed by Tribune Content Agency, LLC.