Japanese - listed in an advert from 1907 this glass could have been made well before then. This glass is apparently still made today and seems to be available in Australia, New Zealand and the U.S. under the name of Floreal. Although it was withdrawn by Pilks Uk 1961 - 1965.
Ref: Pilkington Japanese Sample
Ref: Pilkington Japanese Blue
Ref: Pilkington Japanese Clear
This image is courtesy of the brilliant website http://www.househistories.org/
Ref: Pilkington Japanese Purple
Ref: Pilkington Japanese Yellow