What is a exterior covering, forming a false coat or appendage to a seed, as the loose, transparent bag inclosing the seed or the white water lily. The mace of the nutmeg is also an aril. Gray called?

arillus — A exterior covering, forming a false coat or appendage to a seed, as the loose, transparent bag inclosing the seed or the white water lily. The mace of the nutmeg is also an aril. Gray. (Webster's 1913.)

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