Aril colour

The term aril is generally restricted to fleshy growths from the funicle or from the hilum, i.e. from the base of the seed or its point of attachment. To be classed as an aril it must enclose at least part of the seed. An aril often resembles an egg cup around the base of an egg.  No distinction is made in this key between arils, arillodes and sarcotestas and all are included in the generic term aril.  Arils are usually found on seeds in dehiscent or tardily dehiscent fruits but there are exceptions to this generalisation.  The edible part of a litchi (Litchi chinensis) is an aril.  The fleshy (often brightly coloured) funicle on Acacia seed is not regarded as an aril.