> Leaves of some trees such as birches, tulip poplars, redbud and hickory, are always yellow in the fall, never red.
> The fall leaves of a few trees, including sugar maple, dogwood, sweet gum, black gum and sourwood, are usually red but may also be yellow.
> Unlike the bright colors of flowers, which attract pollinators, or the bright "Warning Colors" of many kinds of animals, the bright colors of fall foliage are a byproduct of chemical changes as the trees start to go dormant. These colors have no apparent biological function or significance.
> The most intense of fall color occurs in in areas such as New England, with almost pure stands of a few types of trees, such as maples and birches, that all turn color at the same time during the short fall season.