SALEM, Ore. — Starting on Saturday, Oregonians can buy marijuana for recreational use at shops intended for that purpose. The Oregon Liquor Control Commission announced on Friday it has approved licenses for 26 retailers around the state, meeting a key deadline almost two years after voters passed a ballot measure legalizing pot. “It’s a pretty exciting day for the OLCC,” Steven Marks, the executive director of the commission charged with regulating recreational marijuana, said in a conference call with journalists.