Saint Luke’s, Page Street: Liriodendron tulipifera, Tulip magnolia

Liriodendron tulipifera

With distinctive square lobed leaf structure, large green and orange tulip-shaped flowers, and woody cone-like seeds, the prehistoric tulip tree is relatively unchanged since the Early Cretaceous period, 145 to 100.5 million years ago, when dinosaurs roamed North America.

Liriodendron tulipifera or tulip tree is a stately, fast-growing, upright, pyramidal tree that broadens with spreading growth as it matures. The native tulip tree reaches over 150 feet in the wild and matures at 80’ by 40’ under urban conditions. The tulip tree is found in deciduous forests east of the Mississippi River, and as far south as northern Florida, and as far north as southern Ontario.

Trees of New Bedford series

Liriodendron tulipifera - Tulip Tree

Submitted by J.E. Ingoldsby, ASLA

· Common Name: Tulip-tree, Tulip Magnolia, Tulip poplar

· Botanical Name: Liriodendron tulipifera

· Distinguishing features: Liriodendron tulipifera or lily tree of many tulip flowers is a stately, fast-growing, upright, pyramidal tree that broadens with spreading growth as it matures. The native tulip tree reaches over 150 feet in the wild and matures at 80’ by 40’ under urban conditions. With distinctive square lobed leaf structure, large green and orange tulip-shaped flowers, and woody cone-like seeds, the ancestral tulip tree illustrates a mitochondrial genome relatively unchanged since the Lower Cretaceous period, when dinosaurs roamed North America.1

· Spring features: The bilateral halves of the leaf are folded into a flag-like outline when the leaf emerges, then they separate like a butterfly's wings at the mid-rib as the leaf expands. Once fully emerged, the leaves are medium green, alternate, and broadly ovate with a square shape, having both a truncated base and a truncated, shallowly wedge-shaped apex, with several shallow lateral lobes and a long petiole. Foliage of this tree flutters in the slightest breeze.

· Summer features: Tulip trees flower in late May and throughout June present large, solitary, showy flowers having six yellow-green petals surrounded by three green sepals and resemble a huge tulip. The interior of the flower contains a bright orange and yellow corolla, surrounding the central spire of immature aggregate fruits. Tulip trees often experience limited defoliation of yellow leaves in the interior of the tree’s crown by late July to early August, as a response to summer drought.

· Fall features: Tulip trees are one of the best trees for yellow to golden-yellow fall foliage color. Each fruit is a green to chartreuse aggregate of samaras in the shape of an upright cone.

· Winter features: Often the tallest and straightest tree in the open field or forest, ascending to great heights before finally losing its central leader and upper branches due to storms that twist the lightweight wood. The bark is distinctive in its light gray shades of youth blending into the light brown tones of maturity, with interlacing ridges that are contrasted with deep furrows on the straight trunks. In winter, the cones turn light brown. Upon their natural separation from the fruits, the winged samaras twirl downward in a spiraling fashion to the ground.

· Crown: If spared by storms, the canopy is broadly pyramidal, widening as they age with stout ribbed limbs, heavy with tulip like flowers in early summer and woody cones in winter. On older trees, the lower limbs become pendulous, allowing for the close examination of the tulip-like flowers.

· Use: A towering, majestic tree for shade, as a specimen, an ornamental, and as a focal point in parks with sufficient room for growth. The tree requires a deep, moist loam to thrive, though it is adaptable to drier conditions. The wood is an important timber tree for veneer and for the pulp industry.

· History in the USA: L. tulipifera is native to North America. It belongs to a more unusual group of dicotyledons (plants with two seed leaves) known as Magnoliids, which are thought to have diverged early in the evolution of flowering plants2.

Tulip trees are considered molecular fossils, representing one of the more primitive flowering plants in existence today, along with the other Magnolias. The tulip tree is found in deciduous forests east of the Mississippi River, as far south as northern Florida, and as far north as southern Ontario.

In the Joyce Kilmer National Forest within the Appalachian Mountains, are virgin forests where these trees grow to more than 200 feet tall. Word has it that when the loggers experienced the magnificence of the tulip trees within the Joyce Kilmer National Forest, they teared up and refused to cut these virgin trees 3. These tulip trees in the National Forest are a reminder of the original forests that stood before industrial logging clear-cut the forest.

Liriodendron tulipifera was one of the primary woods used for tall ship’s masts and Tulip Trees are also a caterpillar food plant for the Eastern Tiger Swallowtail butterfly!4

References:

1. Aaron O Richardson, Danny W. Rice, Gregory J. Young, Andrew J. Alverson, Jeffrey D. Palmer. The "fossilized" mitochondrial genome of Liriodendron tulipifera: Ancestral gene content and order, ancestral editing sites, and extraordinarily low mutation rate. BMC Biology, 2013; 11 (1): 29 DOI: 10.1186/1741-7007-11-29
2. Ian Small. Mitochondrial genomes as living ‘fossils’. BMC Biology, 2013; 11 (1): 30 DOI: 10.1186/1741-7007-11-30
3. Michael A. Dirr, Manual of Woody Landscape Plants, Stipes Publishing, 1998, 572-574
4. Kim Smith, 2012, https://kimsmithdesigns.com/tag/tulip-poplar/