Alder or "brown", which is also a root for the English words "elk" and another tree: "elm", a tree distantly related to the alders. With a few exceptions, alders are deciduous, and the leaves are alternate, simple, and serrated. The flowers are catkins with elongate male catkins on the same plant as shorter female catkins, often before leaves appear; they are mainly wind-pollinated, but also visited by bees to a small extent. These trees differ from the birches ("Betula", another genus in the family) in that the female catkins are woody and do not disintegrate at maturity, opening to release the
Chrysolepis three sweet, edible nuts, eaten by the indigenous peoples. The fruit also provides food for birds and wildlife. "Chrysolepis" is related to the subtropical southeast Asian genus "Castanopsis" (in which it was formerly included), but differs in the nuts being triangular and fully enclosed in a sectioned cupule, and in having bisexual catkins. "Chrysolepis" also differs from another allied genus "Castanea" (chestnuts), in nuts that take 14–16 months to mature (3–5 months in "Castanea"), evergreen leaves and the shoots having a terminal bud. There are two species of "Chrysolepis" — "Chrysolepis chrysophylla" and "Chrysolepis sempervirens" — which like many species