A bill that would limit the size of medical marijuana growing operations in Oregon is generating angry opposition from some patients and activists.

The proposed measure, unveiled late Friday afternoon, is aimed at curbing the black market while prodding larger growers to supply the legal recreational market the state is developing.

This approach is winning wide support on the House-Senate committee charged with implementing the marijuana legalization initiative approved by Oregon voters in November. It also has varying degrees of support from many marijuana industry figures who want to develop a successful legal market in the state.

But the 89-page amendment to Senate Bill 844 quickly created sparks among medical marijuana patients and many activists. Several legislators reported being besieged with emails and phone calls Monday from people worried that they would lose their supply of low-cost medical marijuana.

"It's going to take medicine away from the sickest and most disenfranchised patients," said Alex Rogers, who owns a medical marijuana clinic in Ashland and has been using social media to build opposition to the proposal.

Rogers also charged that legislators were trying to rush the proposal through by unveiling the lengthy amendment on Friday and scheduling a Monday evening work session.

"I think they're trying to pull a fast one on the cannabis community" by not holding a public hearing on the amendment, he said.

Rep. Ann Lininger, D-Lake Oswego and co-chair of the House-Senate marijuana committee, said there was no intent to avoid public scrutiny.

She said the committee members have taken testimony for weeks now on how to revamp the medical marijuana program so that it fits into the overall legalization of the drug.

The new proposal "takes a lot of steps to make sure that growers and patients will have a reasonable transition," said Lininger, adding that lawmakers have an "over-arching duty" to manage legal marijuana in a way that won't run afoul of federal guidelines.

State officials say a large amount of the marijuana that is ostensibly grown for medical marijuana patients gets diverted to the black market. Growers are allowed to grow up to six plants per patient, which in many cases produces far more pot than an individual is likely to consume.

Under the Oregon initiative, possession of small amounts of marijuana will become legal on July 1. Retail sales are not expected to start until late 2016, although legislators are considering a proposal to temporarily allowing medical marijuana dispensaries to sell to other adults.

Here are some of the major limits included in the proposal:

* Existing medical marijuana growers in most areas would be limited to 96 plants, while newer growers would face a 48-plant limit.

* Growers in residential areas within cities would have a 24-plant limit if they were in operation before Jan. 1 of this year. Newer growers would be limited to 12 plants.

* Medical marijuana growers would also have to comply with new reporting requirements and could face lower limits if they violate the rules. Existing growers could also face lower limits if they lose patients.

Lininger said Monday's session is primarily aimed at giving legislators a chance to talk about the proposal and that she didn't expect anything to be passed that day.

"You have to have reasonable regulations on both the medical side and the adult recreational use side," she said.

Amy Margolis, a Portland attorney with the Oregon Cannabis PAC, said her group doesn't take a position on the plant limits in the amendment.

But she praised several of the provisions, saying they will help Oregon develop a strong legal market. That's a primary concern for her group, which includes several members who want to serve the recreational market.

Margolis also said medical marijuana patients would be helped by one provision that would curb the ability of local governments to prohibit medical marijuana dispensaries. In addition, she noted, the proposal would also allow medical marijuana growers to be compensated for their labor by patients.

However, Anthony Taylor, co-founder of Compassionate Oregon, a medical marijuana patient advocacy group, said that legislators should leave the medical marijuana program alone for now.

Instead, legislators should establish recreational sales and then see whether something should be done with how the medical marijuana program works, he said.

"It's really hard to get rid of a black market," he said, "and it's a tricky landscape because it puts so many patients at risk."

-- Jeff Mapes

503-221-8209

@Jeffmapes