Identifying characteristics:
An attractive, large, deciduous tree, 80 to100 feet in height and with a
spread of up to 50 ft. The trunk is usually very straight and tall and has
a diameter of 4 to6 feet. The crown is usually rounded-oval in mature trees.
The leaves have a notched or blunt
apex, 2 lobes near the apex and 2 or 4 lobes on the sides. The margins of
lobes are entire. The 4- to 6-inch-long leaves are simple, alternate and
a lustrous, dark green color, becoming yellow in the fall. The slender petioles
are 2 to 4 inches long with large, prominent, leaf-like stipules in spring,
which fall away when the leaves reach full size, leaving a distinctive line
circling the winter twig at each leaf scar. Trees begin to produce flowers at 5- to 8-years-of-age. Flowers
appear in spring after the leaves have emerged, as large, tulip-shaped,
solitary blooms at the ends of the branchlets. The greenish-yellow, cup-like
flowers are usually too high to view up close, but have a surprising band
of bright orange on the inside and a central, cone-shaped axis bearing the
sexual structures. In the fall a cone-like aggregate of spirally arranged,
indehiscent, winged fruits (samaras)
develops around this axis which remains on the tree through winter. Seeds
are wind-dispersed. The distinctive duck's-bill-shaped, 0.5-inch winter
buds appear terminally, are dark red or green and are formed by the
two bud scales meeting but not overlapping. The
bark is smooth and thin on young trees, becoming thick, rough
and irregularly furrowed with rounded ridges and ashy-gray.
Similar species:
Ecology:
Distribution: Liriodendrons are not related to true poplar trees
(Populus) and there are only two species of liriodendrons in the
world. The Chinese tulip poplar (L. chinense) is smaller, has smaller
flowers and is seldom planted in the US.
Habitat: The tulip poplar is a fast-growing tree (3 to 4 feet per year), native to the forests of the eastern US and normally found at lower altitudes growing on bottomlands and moist slopes. This tree is very intolerant of shade and grows best in full sun on moist, well-drained, loamy soil, although it will tolerate heavier clay soils. Liriodendrons are generally free of pests and diseases, but are susceptible to aphid attack and the associated sooty-mold.
Uses:
Wood: The wood of the tulip poplar makes it a commercially
important hardwood species. The heartwood is light greenish-yellow to dark
brown, lightweight and relatively soft, making it easy to work. The wood
is used for veneer, paper pulp, doors, shelves, core stock for plywood,
and many other products.
Wildlife: This tree is of limited significance to wildlife. Purple finch, cardinal, other birds and squirrels feed on the seeds in the fall and on the seeds that remain in the cone-like structures on the tree through the winter. White-tailed deer browse on saplings and rabbits eat the bark and buds during winter.
Horticulture: Occasionally planted as an ornamental tree in central Iowa, the tulip poplar is not reliably hardy further north.
