The white mangrove grows as either a spreading shrub or medium-sized tree
that reaches 40 - 60 feet in height. The bark is thick and scaly,
reddish in color. Leaves are smooth and opposite, 1 - 3 inches in
length. They are rounded both at their apices and near the petiole,
are leathery in texture, and have 2 small glands on the petiole that extrude
sugars. Leaf color is yellow-green. Flowers are small and white,
blooming at either the leaf axils or branch tips. Fruits are
reddish-green in color, approximately 0.5 inches long, and have longitudinal
White mangroves grow in coastal areas of bays, lagoons, tidal creeks, spoil
islands and mosquito impoundments. They typically grow upland of both
red mangroves and black mangroves, well above the high tide line.
The leaves of the white mangrove are similar to those of other mangrove
species. They are distinguished from the both the black and red
mangroves based on leaf shape. Red mangroves have broadly elliptical
leaves. Black mangrove leaves are narrower, have their undersides
covered with fine hairs, and may be salt crusted. White mangrove
leaves are more yellow-green in color, are more rounded than either red or
black mangrove leaves, and bear 2 small glands at the leaf base.
Mangroves are further distinguished by their roots. Red mangroves have
conspicuous prop roots which grow downward from the branches; black
mangroves have numerous, finger-like projections called pneumatophores which
grow upward around the base of the tree; and white mangroves may have
either of these types of roots, depending on environmental conditions.
White mangroves range along both coasts of the subtropical United States.
On the east coast, they range from Volusia and Levy Counties in Florida,
south through the Florida Keys. The range also includes the West Indies,
Mexico, Central and South America to Ecuador, Peru and Brazil. In the
eastern Atlantic, it is also known to occur in West Africa from Senegal to
Leaves and flowers of the white mangrove. Photo courtesy S. Ewe, Smithsonian Marine Station.
Leaf underside of the white mangrove. Note the small gland on the petiole at the leaf base. Photo
courtesy S. Ewe, Smithsonian Marine Station.
Mangroves utilize a highly specialized method of propagation: their
seeds germinate into seedlings while still on the parent tree. After
an initial period of development, the seedlings drop off the parent tree to
the soft sands below. They may then either sprout, or be carried on
the tide to other locations. Seedlings remain viable for extended periods of
time, possibly up to a year or more.