A female Ginkgo biloba produces seeds that are covered by an outer layer, sometimes referred to as the fruit. Remember, the phylum to which Ginkgo biloba belongs is the Ginkgophyta. Ginkgophyta is one of four phylum classified under the gymnosperms. The word “Gymnosperm” in Greek means “naked seed” or in other words, these trees are not fruit bearing plants. Besides the fact that the female trees bears seeds, the adult form of the female Ginkgo tree is usually pretty easy to tell apart from the male trees because in the fall, the seeds fall and as they start to decay they produce butyric acid, CH3(CH2)2COOH, Butyric acid causes them stink horribly. Some people say the "fruit" smells like vomit other say it has more of a rancid butter type smell; either way, the smell
is not liked by most.
Other than the smelly outer layer, a female Ginkgo tree is also responsible for making the seeds for fertilization. The seeds are made in pairs and each seed is packed inside a fleshy outer covering. This outer covering appears green in early spring, then changes to yellow, and finally, in fall, it turns a brownish-orange color. Some Anthophytes don’t begin producing their ovaries (fruit) until the seed has been fertilized by pollen, but Ginkgo biloba begins to make their fleshy covering to protect the seed right away. In order for a female Ginkgo biloba plant to start producing seeds, it must reach a mature age of anywhere between 20- 40 years old. This may seem like a really late age to start making seeds, but remember these trees can live up to a thousand years old!