Simplify the following text for a Grade 8 native English-speaking person.
Original: It is believed to be a cross of Quercus rugosa and Quercus depressipes It is native to Chihuahua and Durango in Mexico , where there are five known small populations ; one in Durango and four in Chihuahua .
Simplified: It is thought to be a hybrid of Quercus rugosa and Quercus depressipes . It is native to the states of Chihuahua and Durango in Mexico , in which there are five known populations ( all of which are believed to be small ) .