As the cold days of winter arrive, the Farmer's Markets start to fill with bright, sunny citrus fruits in many sizes, shapes, and colors. One such fruit that livens up the cold market days is the Meyer lemon.Meyer lemons are hybrid citrus fruits originally from China. No one's sure exactly, but scientists think they are a cross between a lemon and a sweet orange. These thin-skinned lemons are dark yellow to orange in color, and have a lot of juice and less tart than regular lemons. They're a bit sweeter and lower on acid, too. The rind is smoother and has less pits than regular lemons, and they're rounder.