WILMINGTON, Delaware (Reuters) - Delaware became the 16th state on Friday to legalize marijuana for medical use after the governor signed the bill into law.

The law allows patients who certify they have a serious medical condition such as cancer to possess up to six ounces, or 170 grams, of marijuana.

State-licensed centers will be allowed to grow the marijuana and dispense it to patients 18 and older.

Democratic Governor Jack Markell signed the bill in private without a ceremony, according to his office.

The state Senate passed the measure on Wednesday by a 17-4 vote.

California was the first state to allow marijuana for medical use in 1996.