The 2c Meyer Lemons stamp is the latest in the current Fruits low-value definitives series. The Meyer lemon is native to China and is thought to be a cross between a true lemon and either a mandarin or common orange. It was introduced to the U.S. in 1908, but in the 1940s it was discovered that a majority of the Meyer lemon trees being cloned were symptomless carriers of a virus that had killed or rendered useless millions of citrus trees all over the world. Most of the Meyer lemon trees in the U.S. were then destroyed, after which a virus-free selection was developed in the 1950s and certified and released in 1975 by the University of California as the Improved Meyer lemon.