DesertGold/Moorcroft: https://www.desertgold.us/moorcroft/Moorcroft.html
Moorcroft Pottery HIBISCUS (Walter Moorcroft) Green Square Ashtray Approximate Dimensions: 4.625 " (11.748 cm) length 0.75" (1.91 cm) high Circa: 1970s Stoke-On-Trent, England
Marked "Moorcroft Made in England"