(𓐚) as a determinative for cultivated land in the 8th Dynasty, but in this function eventually changed into the form
(𓈇) in the 11th Dynasty. The water in the canal is conventionally green, or sometimes (lighter) blue; the outline is (darker) blue, perhaps representing mud brick. The phonogrammatic value of mr is derived by the rebus principle from its use as a logogram for mr(“canal”).
Gardiner, Alan (1957) Egyptian Grammar: Being an Introduction to the Study of Hieroglyphs, third edition, Oxford: Griffith Institute, →ISBN, page 491
Henry George Fischer (1988) Ancient Egyptian Calligraphy: A Beginner’s Guide to Writing Hieroglyphs, New York: Metropolitan Museum of Art, →ISBN, pages 35–36
Betrò, Maria Carmela (1995) Geroglifici: 580 Segni per Capire l'Antico Egitto, Milan: Arnoldo Mondadori Editore S.p.A., →ISBN