Trees on the Yale Nature Walk

This Gleditsia tricanthos, or Honey locust, is located in a small green walkway between Winchester Ave and Lockstreet behind Yale Health. The honey locust is a deciduous tree native to central North America. However, it is highly adaptable to different environments, and has been introduced worldwide as an aggressively invasive species, considered as a nuisance by farmers as they grow quickly and outcompete grasses and crops. They can reach a height of around 20-30m; considering our tree is only 7.70m, it is most likely very young. Honey locusts have bright green, pinnately compound leaves which turn yellow in the autumn and are shed in the winter. They leaf out relatively late in the spring (May), when strongly scented, off-white-colored flowers appear. The fruit of honey locusts are flat legumes, which are eaten by herbivores who then excrete the seeds in droppings. The pulp on the inside of the fruit is sweet, where the name Honey locust originates, and has been used for food and traditional medicine as a sweetening agent by several Native American tribes.

The bur oak is a large, deciduous, slow-growth tree with simple leaves and a uniform crown of thick, spreading branches. Bur oaks are extremely resilient, displaying high levels of fire-resistance (thick bark), cold-tolerance, aerosol and soil salt tolerance, and drought resistance (deep taproot), surviving even in mineral-poor soil. The Bur oak has monoecious character with imperfect flowers, with a strategy of masting. This means acorns are produced in large quantities every few years in order to overwhelm consumption by wildlife. Bur oaks have a lifespan exceeding 200 years, approaching 1000 years. It has a wide distribution in North America, being native to Eastern NA. Bur oaks initial height growth is normally slow for the first 3 - 5 years, dependent on environmental conditions (sun exposure in particular). Based on the height, diameter, and growth factor, this individual is approximately 12 years old.

The White Fringetree (Chionanthus virginicus) is a dicot, deciduous tree with grey bark. During the spring and summer the tree blooms with dark green leaves small white flowers that don nicknames such as "Snowflower Tree," "Flowering Ash," "Old Man's Beard," and "Grandfather Graybeard." The the height of our tree is 2.9 meters, but adult Fringetrees can grow up to 10 meters tall. The DBH is 0.040 meters (measuring the four bottom, thickest pieces of the trunk). The fruiting bodies appear as dark blue, oval shaped clusters of drupes. The Fringetree is related to the olive family, and the fruiting bodies reflect this similarity. As White Fringetrees tend to be late bloomers, we won't expect flowers on our tree until April or May, but are excited to smell the famously sweet fragrance when it blooms.

Beautiful little tree located outside of Pauli Murray, perfect size to hug. Friendly tree