aril

Seeds are occasionally covered with a lacy coating. The mace of the nutmeg is an arillus, adhering both to the hilum and micropyle. This coating is called the aril. The true arillus is an accessory seed-covering, more or less incomplete, formed between the time of fertilization and the ripening of the seed, by a growth from the apex of the funiculus, at or just below the hilum.