Jurasic Garden
Is it possible that the "missing link" of the plant world has been found? Scientists have been working on the genetic history of plant evolution, and have been unable to make the link from green, non-flowering plants to flowering plants- perhaps until the discovery and recognition of Amborella trichopoda. This shrub is found of the island of New Caledonia in the South Pacific. Amborella trichopoda was brought to the U.C. Santa Cruz Arboretum in Santa Cruz 25 years ago, but a husband and wife team announced their findings that concludes that Amborella may be the most ancient angiosperm in existence. Search 'Soltis et al' on the Internet to find a detailed list of genetic findings of sample plants. It is technically beyond my scope, but is fascinating none the less.
Amborella trichopoda could be the first of the angiosperms to appear on earth perhaps 135 million years ago. All of our seed producing plants are angiosperms.
Angiosperm means "covered seed", the ovule, the ovary of the plant, is covered within a chamber which makes up the pistil, a specialized, often sticky surface, which receives the pollen grains. Prior to the emergence of angiosperms, gymnosperms, similar to our pines of today were prevalent. Gymnosperm means "naked seed". Pines trees permit the transfer of pollen grains directly to the micropyle, the female component. A small drop of "dew" on the micropyle catches the pollen grain, and as the "dew drop" dries, it draws the pollen into the micropyle where it comes in contact with the nucleus and pollination takes place.
Can you get an Amborella for the back yard? Probably not yet, but in a few years perhaps. As with the Dawn Redwood, thought to be extinct until the 1940's, and now easily found for the garden collector, Amborella may also find it's way into the lay person's garden. The demand to supply arboretums and botanists will likely come first, and then depending on the ease of propagation, it will leak out into the public.
It is a wonderful age we find ourselves in. Once, a rare plant such as Amborella would never have been found in the possession of anyone less than royalty, or in institutes of higher learning. Gardeners access to plant material is almost wide open now.
New Caledonia is one of the hot spots of biodiversity with over 3,000 plant species endemic to the island. A large part of the flora is specialized to ultramafic soils, which are low in nutrients and high in metals to even normally toxic levels. Many of the New Caledonian plants are closely related diversified plants of those that were once native to the southeast region of Australia millions of years ago. The flora on New Caledonia is much studied, beginning with Forsters who accompanied Capt. Cook on the first European expedition to the island, and though out the twentieth century, and research continues today as genetic testing changes the way plants are classified and reveals secrets previously veiled to us. Currently 50 species of plants are considered endangered on New Caledonia, although the threat to flora and vegetation of New Caledonia is considered lower than to most tropical regions.
Back in California, our own botanical history is rich and ancient; we need to do what we can to protect and defend our own natives. They are precious and delicate, and once they are gone …. It should not be on our heads that we as a species have caused the demise of another. It is acceptable that nature through weather and geographic changes should alter the genetic mix, but we must be very careful in what we meddle. We as gardeners have a responsibility to protect what others will not. Education of our children and ourselves is the only way to develop an environmental conscience and responsibility that will protect and reclaim what has been lost.
Carol de Maintenon is a member of Garden Writers of America and owner of Benicia Garden & Nursery.
