Updated 3:40 p.m. Wednesday, Jan. 15

Advocates for partly legalizing the growing and use of marijuana in Missouri have gotten the go-ahead to circulate 13 different initiative petitions in the state.

But that doesn’t mean any of the proposals will be on this fall’s ballot.

On Wednesday, the Missouri secretary of state's office said it had approved all 13 initiatives for circulation. Nearly 158,000 signatures from registered voters will be needed to put any of the proposed constitutional amendments on the ballot.

“We’re not going to gather signatures until we do polling,’’ said Dan Viets, a lawyer and chairman of the board for Show-Me Cannabis Regulation, the group seeking to change Missouri’s marijuana laws.

The polling will be of likely voters in this fall’s elections, Viets said. At least 60 percent of those polled must support the partial legalization of marijuana – or the group will hold off until 2016 or later.

“If it looks like we’re not going to win, we won’t even try,’’ Viets said.

The group plans to poll within the month, he said. The costs will be covered by unnamed contributors, primarily “foundations and individuals.”

Viets is somewhat optimistic because a 2011 poll of Missouri voters showed that just over 50 percent supported the idea of regulating marijuana like alcohol.

However, he noted that voters in non-presidential elections often are more conservative and “not quite as progressive or open-minded.”

The 13 initiative proposals are patterned after the successful ballot measures in Washington state and Colorado, although Viets notes some differences.

All the proposals are constitutional amendments to “allow the production, sale, distribution, and consumption of marijuana and hemp products by persons at least 21 years old.”

Also legalized would be the use of marijuana for medical purposes.

All would allow the state “to establish a tax and authorize regulations and licensing procedures for marijuana.”

In effect, the initiatives propose that marijuana be regulated like alcohol, Viets said.

Viets said an economist has determined that Missouri could collect $150 million more in taxes each year by regulating marijuana.

Some proposals would allow old marijuana convictions to be expunged from records, while others would not. Some call people convicted solely on marijuana charges to be released from prison, and some do not.

All of the proposals would allow some marijuana to be grown for personal use, although the amount varies. For example: Some initiatives would allow four plants, while others would allow six or eight.

Viets said that Missouri group won’t follow Washington state, which doesn’t allow the private growing of marijuana plants. He emphasized, “We want some personal cultivation.’’

Viets, by the way, knows a lot about marijuana. Many of his clients have been arrested for marijuana possession.

“Most drug arrests in Missouri are for marijuana,” he said, and generally for possession only. Not for selling, using or growing it.

Viets said he's also working with state Rep. Rory Ellinger, D-University City, who has filed two bills this legislative session dealing with marijuana. One would decriminalize the possession of small amounts of the substance, while the other bill would legalize marijuana for medical purposes.