Original: By that time the Bartlett variety had become vastly popular in the United States, and they are still generally known as Bartlett pears in the U.S. and Canada, although there are about 150 other synonyms worldwide.
Simplified: By that time the Bartlett variety had become vastly popular in the United States, and they are still generally known as Bartlett pears in the U.S. and Canada, although there are about 150 other names worldwide.