Picture #1
Picture #2
Ginkgo biloba is dioecious, meaning that there are separate male and female trees. The female reproductive structure is stalked, with a pair of terminal ovules (See picture #4). The male microsporangiate strobili are located on the short stems. Pollination occurs in April, and throughout the summer the pollen maintains a haustorial relationship with the female gametophyte by nourishing itself off the nucellar tissue. Maturation of the male and female gametophytes occurs during the summer, culminating with fertilization in September. Upon ripening of the fleshy seed coat, the female tree has a distinctive foul odor. Growth and development of the embryo continues throughout the winter (see picture #5), germinating the next year in June.
Picture #4
Picture #5
Ginkgo biloba - "A living fossil"
Ginkgo biloba also has a unique leaf structure. The leaves are fan-shaped and exhibit dichotomous venation (See picture #3). The leaves located on short shoots or on basal regions of the long shoots are entire or divided by a distal notch. In contrast, leaves on the upper portions of the long stem are divided into two lobes by a deep notch.
Ginkgo biloba, commonly known as the maidenhair tree, is the only remaining species within the Phylum Ginkgophyta. Though not found in the wild, this gymnosperm is widely used as a street or yard tree in areas with a temperate climate. There are many interesting characteristics of Ginkgo biloba, including specialized morphological and reproductive traits.
Picture #3
The maidenhair tree exhibits a dimorphic shoot structural pattern known as long-shoot, short-shoot (See picture #1.) The long shoots, which are characterized by widely separated nodes and leaves, result from a longer period of cell division and elongation in the apical meristem. The short shoots have a compacted morphology. The age of the short shoot can be determined by counting the internodes (See picture #2).
by Nicholas Ruppel