Florida Governor Rick Scott signed a law on Monday allowing for the limited use of a special strain of marijuana to treat epileptic seizures and other diseases.
State lawmakers passed the measure this spring with bipartisan support after impassioned appeals from parents seeking access to the form of marijuana known as "Charlotte's Web," named for a Colorado girl whose epileptic seizures have shown some response to the drug.
"As a father and grandfather, you never want to see kids suffer," Scott, a Republican, said in a statement. "I am proud to stand today with families who deserve the ability to provide their children with the best treatment available."
The "Compassionate Medical Cannabis Act" will severely limit marijuana sales, keeping them well below those in Colorado and Washington state, where recreational marijuana has been legalized.
The Florida law allows use of the drug for people suffering from epilepsy, cancer and amyotrophic lateral sclerosis (ALS), known as Lou Gehrig's disease.
The Charlotte's Web substance is not for smoking and is specially cultivated to be very low in tetrahydrocannabinol (THC), the element that gets users high.
"I'm thankful. When we began the legislative session, I did not feel the governor would support any marijuana legislation," said state Representative Katie Edwards, a South Florida Democrat who co-sponsored the legislation.
Edwards joined forces with Republican state Representative Matt Gaetz to back the bill despite being on opposite sides of the medical marijuana debate. Edwards supports broader use of medical marijuana, while Gaetz is opposed.
Gaetz said "Charlotte's Web," an oil extract placed under the tongue, is not a step toward marijuana legalization.
After Jan. 1, 2015, doctors will be allowed to prescribe low-THC marijuana treatment for state residents with epilepsy, cancer and afflictions causing "seizures or severe and persistent muscle spasms."
The bill also appropriates US$1 million (S$1.3 million) for medical research in medical uses of marijuana.
Florida is estimated to have 125,000 epilepsy sufferers.
The new law limits production to a few growers at nurseries that have been in business for 30 years or more.
The law is not related to a more expansive medical marijuana referendum up for vote in November, with polls showing widespread support.
Twenty states and the District of Columbia have some form of laws that permit the use of marijuana for medicinal purposes, though they vary widely, according to a Florida legislative analysis.