proplastiidide kloroplastideks diferentseerumisel pimedas moodustuv vahevorm, mis ei sisalda klorofülli, vaid värvitut protoklorofülliidi, Etioplasts are intermediate form of chloroplasts that have not been exposed to light containing colorless protochlorophil instead of green chlorophyl. They are usually found in flowering plants (Angiosperms) grown in the dark.