Margaret Constance Helen Blackler (1902–1981) was a British phycologist, botanical collector and museum curator.
She also had some temporary teaching posts at colleges and the universities of Liverpool and Sheffield.
[2] At Liverpool Museum she curated historic plant specimens that had been added to the herbarium.
[2][1] Blackler's over 39 scientific publications and books include: She identified at least 38 specimens of marine algae, particularly of the Scytosiphonaceae species Colpomenia peregrina Sauv.
She carried out her doctoral research under the supervision of Margery Knight, thus becoming involved with marine algae, and her Ph.D. was awarded in 1928 for her thesis "A Morphological and Cytological Study of Certain Species of Asperococcus".