The term derives from the Latin word pinna meaning "feather", "wing", or "fin". A similar concept is "pectination", which is a comb-like arrangement of parts (arising from one side of an axis only). Pinnation is commonly referred to in contrast to "palmation", in which the parts or structures radiate out from a common point. The terms "pinnation" and "pennation" are cognate, and although they are sometimes used distinctly, there is no consistent difference in the meaning or usage of the two words.[5][6]
^Nicholas Eastaugh, Valentine Walsh, Tracey Chaplin, Ruth Siddall. Pigment Compendium: A Dictionary of Historical Pigments. Butterworth-Heinemann 2008. ISBN978-0-7506-8980-9.
^Charles Seymour Wright, Raymond Edward Priestley. Glaciology. Harrison and Sons, for the Committee of the Captain Scott Arctic Fund. 1922.
^Journal of the Electrochemical Society, Volume 100, 1953, page 165: "The zinc is recovered electrolytically as 'flake' powder consisting of pinnate crystals."