Blessed with an impressive form, a hardy nature and unique leaves, maidenhair trees (Gingko biloba) are as attractive as they are interesting. With evolutionary roots extending deep into geological time, these leftovers of an ancient world have proven to be resilient survivors, who are even capable to thriving in 21st Century urban habitats.
Though their branches often develop irregularly, maidenhairs typically achieve an aesthetically pleasing form. Maidenhair trees become quite large with age, sometimes surpassing 120 feet in height.
The distinctive bi-lobed leaves of maidenhair trees make them hard to mistake them for anything else. In fact, their specific epithet – biloba – means two-lobes (the name maidenhair refers to the species’ superficial resemblance to maidenhair ferns of the genus Adiantum). As deciduous trees, maidenhairs shed their entire canopy each winter. However, before dropping to the ground, the leaves turn a beautiful shade of gold. Given their typically picturesque growth form, large specimens can be absolutely breathtaking in the autumn.
Maidenhairs are dioecious trees, meaning that individuals are either male or female. Female plants produce copious amounts of seeds that fall to the ground in the late fall or early winter. These seeds are covered with a foul-smelling seed coat, which many people find highly objectionable. The males produce no foul-smelling seeds, but they produce highly allergenic pollen.
As evidenced by their placement in the tree of life, maidenhair trees are some of the most unique organisms on the planet. Botanists consider maidenhair trees (Gingko biloba) to be the only living descendants of an entire phylum of plants.
To put this into some context, consider that every flowering plant in the world – from sunflower to redwood — is classified in the phylum Anthophyta. Scientists only recognize nine such groups (phyla) of living plants. Conifers form their own phylum, as do all ferns, horsetails, cycads, club mosses, gnetophyes and whisk ferns. And, as we said at the outset, maidenhair trees form their own phylum, called Gingkophyta.
Maidenhairs had evolved by about 200 million years ago, and these ancient specimens strongly resemble the living species. Accordingly, many biologists call them “living fossils,” as they are living remnants of an ancient world. While some of the oldest maidenhair fossils exhibit a different form of seed attachment than living specimens do, those from about 65 million years ago are virtually identical to the modern form.
Culture, Cultivation and Cuisine
Maidenhair trees have played an important role in human culture, although this history only dates back about 1,000 years. People have grown maidenhair trees ornamentally for much of this time and harvested the seeds as a food source and for use in traditional medicine. Maidenhair trees are also popular subjects for the practice of bonsai.
Formerly found all over the globe, maidenhairs had virtually disappeared by about 2 million years ago. But before they could disappear forever, humans eventually found and cultivated some of these scattered survivors, thereby allowing the trees to be widely available in the modern world. The only known wild populations of the trees currently grow in a few Chinese localities.
Maidenhairs prefer forested sites, with well-drained, acidic soils, but they are highly adaptable trees that can live in a variety of habitats – including urban areas. Because they tolerate the indignities of city living, maidenhairs have become popular street trees, commonly planted throughout Europe, North America and Asia. Though they rarely escape cultivation in North America or Europe, they often become naturalized in parts of Asia.