Ginkgo

Basic Information
Tree ID: 
41
Family: 
Ginkgoaceae
Genus and species: 
Ginkgo biloba
Description: 
This ginkgo tree is located in the backyard of President Peter Salovey's house, between Hillhouse and Whitney Avenue. A living fossil, Ginkgo biloba has been found in fossils from as far back as 270 million years ago. The species originated in China and has a history of being used for medicinal purposes. Ginkgo trees are prized in Asia because of their importance in Buddhism and can be found in palace and temple gardens. They are a hearty species and survive well in cities so can also be found in devleoped areas from New York City to Tokyo. Before its foliage has been lost, the tree can be easily recognized by its unique fan-shaped leaves. The foliage turns from green to a golden-yellow color in the fall. Male trees are preferred because female trees produce fruit that emits a foul odor.
Surveyors: 
Howie Xu, Shiori Tomatsu, Catherine McGeoch
Location
Area: 
Hillhouse
Collected Data
Tree shape: 
Pyramidal
Date of tree entry: 
03/03/2016
Height: 
18.77 m
Diameter at breast height: 
0.70 m

Bark
The bark is gray in color and quite rough. It is broken up by furrows that range from shallow to fairly deep. The bark seems to be made up of layers that can chip off with relative ease. Small patches of lichen can be spotted along the length of the bark.
Twigs & branches
Ginkgo branches extend in length from base shoots. After a year of growth, short shoots up to three inches long will grow along the branches. Leaves grow in clusters from the tips of the spur shoots.
Foilage
The two-lobed ginkgo leaf is unique for its fan-shaped structure. Ginkgo leaves exhibit a dichotomous venation pattern, that is, veins split in two directions at the base of the leaf. They are usually about 5-10 centimeters long. The leaves are green in the summer, yellow in the fall, and fall off during the winter.
Reproductive Structures
Ginkgo trees are dioecious, that is, male and female flowers are found on separte plants. Flowering occurs in the spring, and the flowers are green with a pleasant fragrance.
Fruit
Ginkgo fruit is known for its notoriously bad smell. The outer part of the seed produces the unpleasant odor. It is likely that at some point in history, this characteristic evolved to attract animals to eat and disperse its seeds, but today, it is not known to attract wildlife. Ginkgo seed dispersal remains somewhat of a mystery. It is possible that its animal pollinators are extinct; however, the seeds do have a significant amount of nutruients, which could attract squirrels. The fruit is fleshy, tan or orange-colored, and ovular.
Seasons
  • Fall
  • Winter
  • Spring
  • Summer
Research
Natural range of distribution: 
Habitat: 
Ginkgo biloba originated in China and has long been cultivated there and in other parts of Asia. The species grows in a temperate climate with deep soil. Ginkgo trees are extremely adaptable and are resistant to pollutants, fungicides, insects, and drought. Because of this versatility and their unique appearance, ginkgo trees are planted in many large cities in Asia, Europe, and the eastern part of the United States. In fact, the ginkgo is the most widely planted tree in New York City.
Origin, history, and uses: 

Ginkgo biloba, named for its unique leaves, means “two lobes.” It has been found in fossils from 200 million years ago and has barely changed, such that it can be considered a living fossil. It has no living relatives. 

The first ginkgo tree is believed to have been cultivated in China 1,000 years ago and traded to Korea and Japan by the 14th or 15th centuries. The trees came to Europe around the 1750’s. 

Ginkgo is sold widely today in health stores and is known particularly for helping memory. In ancient China, seeds were used for medicinal properties, whereas today, leaf extracts are sold. 

The ginkgo tree is a hearty one that does well in urban environments and so is a preferable choice for landscaping in city settings. Only male ginkgo’s are used, however, because females produce the foul-smelling fruit. Ginkgo trees can be found all over Seoul and Manhattan. 

Phenology: 
The ginkgo tree produces its seeds during the warm climate/warm seasons. These germinate earlier in the year than the ones produced during the cold seasons. The embryos of the ginkgo seed has a temperature dependent developmental delay mechanism that allows them to survive winter by preventing premature maturation in the fall. In warm-temperate climates ginkgo seeds are shed in late summer or early fall, and the embryo is able to make considerable growth during the mild weather that follows immediately after. In cold-temperate climates seeds are shed much later in the season, and the cooler temperatures of mid- to late fall delay embryo development until warm weather arrives in the following spring. The ginkgo tree is dioecious (produces pollen and seeds on separate plants). The pollen is dispersed via wind. Once the seeds fall off the tree in autumn and become fertilized, they can be dispersed by animals in order to distribute the species. One of the ginkgo's main dispersers is the gray squirrel.
References: 

Cohn, Roger. “Ginkgo: The Life Story of the Oldest Tree on Earth- Interview with Peter Crane.” Yale Environment 360. 01 May 2013. http://e360.yale.edu/feature/peter_crane_history_of_ginkgo_earths_oldest… Accessed 4/24/16. 

Del Tredici, Peter. “The Phenology of Sexual Reproduction in Ginkgo biloba: Ecological and Evolutionary Implications”.  The Botanical Review, 73(4):267-278. The New York Botanical Garden.  http://www.bioone.org/doi/pdf/10.1663/0006-8101(2007)73%5B267%3ATPOSRI%5D2.0.CO%3B2 Accessed 4/24/16.

“Ginkgoales: More on Morphology.” University of California Museum of Paleontology Berkeley. http://www.ucmp.berkeley.edu/seedplants/ginkgoales/ginkgomm.html Accessed 4/24/16.

“Ginkgo biloba- The Maidenhair Tree.” The University of Wisconsin La Crosse. http://bioweb.uwlax.edu/bio203/2011/lehrer_brit/habitat.htm Accessed 4/24/16. 

“Plants Profile for Ginkgo biloba (maidenhair tree).” USDA Natural Resources Conservation Service. http://plants.usda.gov/core/profile?symbol=GIBI2 Accessed 4/24/16. 

 
More
Media and Arts

“Ode to the Ginkgo”

Magical ginkgo, you have a mighty soul

that withstands pollution and still grows tall

Your fan-shaped leaves and healing power make you unique   

But that fruit of yours, we hate to say, makes you reek
 

How then have you survived for so long?

You’re a living fossil so you really can’t do wrong

These past few weeks with you have been the best

And with your christening, we have one final request:

Ginkgo biloba, you beautiful tree,

Serve as a pleasant beacon for Yale and EEB 223!

Comments

Alina Nevins on May 4, 2016:

Check out 99% Invisible’s podcast about the urban wilderness.

This whole episode is A+, but the Ginkgo portion which starts at around 14:30 is A++. Enjoy!

-Matt Reynolds