I was driving along 10th avenue in Vancouver, British Columbia when my passenger, awed by by the towering tree canopy overhead, asked me which species of street tree we were seeing. I was embarrassed that I did not know the answer to her question, and set out to learn more about this species. A quick online search revealed that the trees along 10th Avenue are tulip trees, or Liriodendron tulipifera. Thankfully, I was able to find many excellent photos of this species.
Liriodendron tulipifera is a large, stately tree species that can reach heights of nearly 70 meters. It has a straight trunk, self-pruning branches, and an oval growth habit. The leaf shape of Liriodendron tulipifera is unmistakable; each long-petioled leaf has four lobes separated by rounded notches. The flowers are also striking, and their tulip-like appearance gives this species its name. The flowers are greenish-yellow and have 5 petals and three sepals. Once pollinated, these give way to a cone-like structure consisting of numerous dry, winged samaras (winged achene fruit) that often remain on the tree after the leaves drop in autumn. Only one other species, Liriondendron chinensis, shares the genus.
This tree species is native to the eastern deciduous forests of North America. It is the tallest hardwood species in its range. Liriodendron tulipifera had names that translated to canoewood by the First Nations peoples of eastern North America, because its long, easily-worked straight wood was ideal for the crafting of canoes. The same characteristics make Liriodendron tulipifera an important timber species today. Silviculturists also have their own names for this species: tulip balsam or yellow balsam. Margo Reynolds, in her 1976 article, Liriodendron tulipifera–Its Early Uses (PDF, and scroll down) describes some of the qualities of tulip tree wood that made it particularly prized by the early settlers of North America. Properties such as a fine, uniform grain and the ability to take both paint and varnish made this wood particularly useful for the construction of the many objects needed by the settlers. They used tulip wood to make containers and carved furniture as well as more mundane objects such as shingles and joists.
The material use of Liriodendron tulipifera is interesting, but what I find even more fascinating is the symbolism associated with this tree species. In the article cited above, Reynolds remarks that the tulip tree was known as the “tree of liberty” during the American Revolution. In the time period leading up to the American Revolution, colonists would rally against the British around large, stately trees. Each of the colonies had their own liberty tree. While these liberty trees were sometimes elms (Ulmus americana) or London planes (Platanus x acerifolia), they were often tulip trees. When the British encountered these trees, they would cut them down. The last surviving liberty tree in the United States was a 400 year old Liriodendron tulipifera, located on the campus of St. John’s College in Annapolis, Maryland. A hurricane in 1999 did irreparable damage to the tree, and it was cut down during a solemn ceremony later that year. The tree lives on in the wood of 400 “liberty tree guitars” and in many seedlings that have been planted to commemorate the American Revolution (see: The Maryland Liberty Tree).