Assemblyman Jim Wood’s bill allowing Californians to use the first federally approved medicine made from marijuana was signed into law Monday by Gov. Jerry Brown.

Wood, a Santa Rosa Democrat who chairs the Assembly Health Committee, authored the bill that allows California physicians to prescribe a drug called Epidiolex for treatment of two rare and severe childhood-onset epilepsies.

The drug, produced by GW Pharmaceuticals, is the first approved medicine that “contains a purified drug substance derived from marijuana,” the Food and Drug Administration said in a statement announcing its approval last month. It contains cannabidiol (CBD), a component of marijuana that delivers no mind-altering effects.

Before Epidiolex can be prescribed, it must be removed from the Drug Enforcement Administration’s list of Schedule 1 controlled substances, which Wood expects to happen by late September. Wood’s bill makes it legal under California law.

The two childhood disorders — Lennox-Gestaut and Dravet syndromes — afflict fewer than 45,000 Americans, but GW Pharmaceuticals expects Epidiolex will be used for other types of epilepsy.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.