Botanist Lens: "Dinosaurs" of the garden: the living fossils

  

Around the time that the sugar Maples starts showing off the fall leaf colors with an array of yellow, orange and red mixed together, there is one plant that is turning rich golden yellow quickly. The exquisite leaves of the one and only Gingko species turns from dark green to chartreuse green mixed with yellow and then turning all golden yellow before they drop.

 

 

 

Gingko Biloba (Family: Gingkoaceae) is suitable for a wide range of plant hardiness zones from Zone 3A to 8A. They tolerate moist compacted soil and usually grow slowly getting upto 75 ft. tall. The common name is Maiden hair tree which is also similar to "Maiden hair fern" Adiantum sps. and both these species have fan shaped leaves. For commercial plantings, usually a male Gingko tree is used, the females are wider and have a pungent order to its fruit.The leaves however are the best aesthetic feature of this plant, turning golden yellow for a very short period in early fall.

 

 

 

Now what has this elegant, one of a kind Ginkgo tree got to with the gigantic Dinosaurs? "The first Ginkgo leaves were found from the Triassic period, but there were many species of Ginkgo during the Jurassic and Cretaceous periods as well" (https://en.wikipedia.org/wiki/Ginkgoales). It is a monotypic genus, only one genus and species and is an extant (only species alive) of the Ginkogales. The oldest fossil of a Ginkgo leaf its around 200 million years ago!

 

They are the oldest tree on the planet and aptly called the living fossil plants on the Earth. The term "Living fossil" was first coined by Charles Darwin, the great biologist and naturalist who coined the theory of evolution. Ginkgo biloba is also a species that has survived with little changes over a large span of time. From a botanical view point, the extant Ginkgo biloba is of very high value to understand evolution of flowering plants. But this tree should certainly be of interest to anyone, especially children since the dinosaurs roamed freely around them!

 

 

 

Another very interesting group of plants found growing at London Town and Gardens are the Star Anise Illicium sps. Illiciums are from the cretaceous times. In fact, since they developed in the deeply shaded cretaceous conifer forests, they can't tolerate much direct sunlight and only prefer deep dappled shade. The leaves start yellowing instantly when placed in too much sun. The attractive and important horticulture facet of this plant is the start shaped fruit called "start anise" which is used as a condiment. (In Indian cuisines, it is used to flavor rice and the taste is similar to licorice and cumin mixed). But beware, some species of Illiciums are very poisonous, including the native Illicium floridanum (deep red flowers).

 

 

 

Illicums are one of the earliest flowering plants on Earth, infact their vascular structure very closely resembles gymnosperms. The basal angiosperms, the earliest flowering plants on this planet are grouped together in the "ANITA grade". Illiciums belong to the ANITA grade and to give you a preceptive of how far back these date "the first three branches of the angiosperm phylogenetic tree consist of eight families with ~201 species of plants (the ANITA grade). The oldest flower fossil for the group is dated to the Early Cretaceous (115 – 125 Mya)" (https://www.srs.fs.usda.gov/pubs/33527).

 

Come and enjoy these living fossils growing at London Town, while you also stroll through the woodland gardens which are speedily preparing for the dormant season.

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