10. Ginko Tree
Gingko biloba: Maidenhair (Ginko) Tree
Cultural Significance
Ginkgo biloba, a rich cultural history which includes landscaping and pharmaceutical use. Before
botany was a modern science, people understood the importance and beauty of plants
and trees. Gingko was recognized and cultivated by indigenous people thousands
of years ago. Although modern scientific instruments were years away, avid plant
enthusiasts created impressive private tree collections. The majority of those who
were able to construct these private tree collections were wealthy landowners.
The 18th century upper class had the capital to spend on luxury goods, including
exotic trees. Large estates throughout Europe had intricate gardens and the rarer
the tree, the more the owner could boast. During the 18th century, Europeans (and
wealthy Americans) regained interest in the treasures of the orient. China was
known for exotic and beautiful treasures, including plant life. Gingko biloba was instantly identified as an exotic species because its physical features were
so radically different than native European trees. For this reason, Gingko was singled
out as a “must have” for plantations and estates. The first known Gingko biloba in the United States was recorded in 1784 and belonged to the wealthy landowner
William Hamilton. William Hamilton’s palatial estate was known as “Woodlands.”
The Hamilton family owned the tract of land that would eventually become west Philadelphia.
Native Ecosystems
Millions of years ago, Ginkgo trees were found throughout much of the northern hemisphere. They are generally considered the oldest representative of the gymnosperm distinction. The ice ages killed many of the related species of the Gingko, but the fertile valley of the Yangtze River in China served as a point of refuge. Within the valley, they were cultivated for thousands of years and spread throughout Asia as people migrated out of the valley. Gingko biloba can stand a variety of soil types and acidities. They require adequate sunlight and the soil must be fairly well drained.
Beneficial Uses
Ginkgo supplements are popular to this day and extracts are included in popular energy drinks, though the efficacy of the amount used is questionable.
The medicinal qualities of the Ginkgo Tree have been well advertised. Promoted as a possible memory enhancer, the chemical components of Gingko leaves and seeds responsible for this reputation are glycosides and gingkolides. These compounds have antioxidative and anticoagulative properties. In ancient China, the leaves and seeds were made into herbal teas. Despite their rancid smell, the seeds were incorporated into traditional cooking. Gingko “nuts” have persisted into the present and remain a part of traditional Chinese wedding banquets and some Japanese dishes such as chawammushi. Gingko nuts are used as an aphrodisiac. Nonetheless, it should be mentioned that the seeds can be toxic in large amount and their consumption should be limited, especially by children.
The Ginkgo biloba is a resilient tree that does well in urban and bucolic surroundings. Ginkgo has a high tolerance for pollutants and salt, which makes it useful as a sidewalk shade tree. The wood of Ginkgo Tree is yellow and brittle and not sought after for any particular qualities.
Biological Characteristics
The popular and inimitable Maidenhair Tree, Ginkgo biloba, has a distinct biological lineage. Much like the Japanese Umbrella Pine, Ginkgo biloba is a survivor from the distant past, the only living member of its family. Gingko tree is often referred to as a “living fossil,” because it has unique characteristics that allow botanists to speculate about the forests of the past. The Gingko tree is ancient, in regards to both its genetic family and its lifespan. Ginkgo can live close to a thousand years and China has made claims of having Ginkgos that are 3,000 years old. Gingko biloba is a deciduous tree, whose distinct leaves turn an electrifying yellow in the fall. It can grow to a maximum height of fifty feet, with a possible spread of 35 feet in an oval-shaped crown.
The bark of the trunk is a pleasant gun-metal grey with deep ridges usually running vertically. The leaves of the Gingko are a distinct fan shape, specific to this species. The deep-green Ginkgo leaf is recognizable even to those with little botanical experience. Leaves are simple; fan shaped and have lobed margins. A typical leaf is 2-4 inches in length and has a tough, leathery-paper feel. Visually, leaves tend to have a stranding effect, which garnered the name “Maidenhair Tree.” This common name may also have been generated by its visual similarity to the “Maidenhair Fern.” Very old Ginkgos may spontaneously generate aerial roots, called “chichi,” which is Japanese for “nipple.” Little is known about their function, other than that “chichi” may be a form of asexual reproduction.
The Gingko Tree is dioecious, having separate male and female trees. Male trees produce pollen and female trees produce “fruit-like” envelopes that develop into seeds. The naked seeds found on the female tree are noted as being malodorous and there scent is compared to rotten flesh or rancid butter. For this reason, the male cultivar is recommended for landscaping purposes.