Ginkgo Leaves Falling

By Steven Foster.

The brilliant golden yellow leaves of the Ginkgo trees flanking the back entrance of our local post office, once they are ready to fall, will  drop in a few hours time, raining from the thick branches like small fans twirling from the sky. After our first hard killing freeze last night, the Ginkgo leaves fell today.

Ginkgo tree with golden leaves on 11 November 2013
Ginkgo tree with golden leaves on 11 November 2013
The same Ginkgo tree on 13 November 2013, minus its leaves.
The same Ginkgo tree on 13 November 2013, minus its leaves.

The shriveling fruits, which look like half-sized wild persimmons, may persist for a few days after the leaves, then fall to the ground. Fruits are always a tempting curiosity. In fact, you can buy Ginkgo seeds as a food item in Chinese markets, but these have been prepared and processed to render them safe to eat. You should not be tempted to pick-up the freshly fallen fruits, which will cause contact dermatitis similar to the rash produced by poison ivy. The fruits have a fragrance that has been described as a blend between baby vomit and what a dog might leave on a sidewalk. That should be enough to entice you to leave them be.

I suspect that these trees were planted about the time the Eureka Springs Post Office building was completed in 1918, rather than in 1973 when the building was expanded and the service parking lot in the back was developed. The trees are of a fairly good size, plus for many decades most ginkgo trees available from nurseries in the United States have represented male branches grafted on to rootstocks. Within forty years after Ginkgos were widely planted as a street tree by the mid 1800s, female trees like those at Eureka Spring’s Post Office began to leave their bad smelling fruits on sidewalks. Female Ginkgos are simply not a neat and tidy street tree. Notwithstanding the beauty of the fall foliage, the fact that these two trees are females makes them a unique and interesting part of Eureka  Springs’ heritage.

Beneath the Ginkgo tree, 13 November 2013
Beneath the Ginkgo tree, 13 November 2013

Ginkgo was common 175 to 200 million years ago, when dinosaurs roamed the earth.  This primitive tree is considered the oldest living tree species on earth.  Ginkgo is monotypic. That is, in the ginkgo family there is only one species in one genus — the only surviving member of the ancient and primitive ginkgo family—Ginkgoaceae. Ginkgo has been cultivated in East Asia for hundreds of years. Numerous reports mention the existence of large specimens, some more than a thousand years old, at ancient temples in Japan and China. The tree was first introduced to North America in 1784 in the garden of William Hamilton at Woodlands near Philadelphia.  Mature ginkgos are said to reach over 100 feet in height.  Its longevity as individual trees and a species in general can in part be attributed to its exceptional resistance to pests and resiliency to destruction by fire. It is also extremely tolerant of air pollution thriving in the harshest urban environments.

Ginkgo leaf extracts are highly complex, highly concentrated preparations with an average  ratio of 50 parts ginkgo leaf to one part of the finished extract by weight. Numerous chemical constituents are found in the extract. Normally ginkgo leaf extracts are calibrated to contain 24 percent flavone glycosides (but may range from 22 to 25 percent) which are a relatively ubiquitous group of compounds found in numerous plant species.  Another important compound group in ginkgo leaf extracts are mostly unique to ginkgo — the ginkgolides — including ginkgolides A, B, and C (around 3 percent) and bilobalide (also about 3 percent). As the oldest living tree species on earth, it is no surprise that it would harbor chemical components rare in nature. Perhaps these extremely complex, large molecules have helped it survive for eons. In addition, during the manufacturing process another group of compounds, ginkgolic acids, which are perceived as potentially toxic, are reduced to below 5 parts per million. Given the specific chemical make-up of ginkgo leaf extracts, it  becomes clear why you can’t apply the results of studies with Ginkgo leaf extracts to a simple tea made from ginkgo leaves. Ginkgo tree, Ginkgo leaf, Golden autumn Ginkgo leavesNumerous pharmacological and clinical studies on Ginkgo leaf extracts have demonstrated a positive effect in increasing vasodilation and peripheral blood flow rate in capillary vessels and end-arteries in various circulatory disorders, varicose conditions, post-thrombotic syndrome, chronic cerebral vascular insufficiency, short-term memory improvement, cognitive disorders secondary to depression, dementia, tinnitus, vertigo, antioxidant activity, among other effects.

Ginkgo tree, Ginkgo leaf, Golden autumn Ginkgo leaves

Watercress—A Kindred Herb

By Steven FosterWatercress, Water Cress, Nasturtium officinale, Rorippa nasturtium-aquaticum

As we transition through the seasons, signs of the past blend with what is to come. Cool spring-fed creeks hold for me a reminder of spring; before winter has yet to begin. Perennial and annual wildflowers along creek banks have gone to seed and turned dormant. The leaves of deciduous woody plants fade from green hues to fall colors, whether vibrant or dull. It’s easier to get to the water’s edge, though stick-tights, beggar’s lice, and other hooked, barbed or Velcro-like seeds and dry fruiting bodies will snare your clothing, hitching a ride, choosing you are their seed-dispersal vector.

One plant that hunkers down during the hot weather, then turns lush in spring fed moving water in the Ozark winter is watercress. Bunches of watercress sometimes make their way to groceries or places where specialty vegetables are sold. As a rather hot-tasting mustard, one can only eat so much of it. Watercress is best used as a secondary leaf ingredient in a fresh salad or a great soup vegetable.  It is a kindred herb, a neglected free food, best at this time of year before it flowers and produces seed in the spring, at which time the leaves become more pungent and less palatable. By Thanksgiving ,watercress has shed it’s straggly summer growth and its fast-growing leaves are tender, lush and vibrant. Take it from waters that are free from pollutants, as the leaves can uptake toxins and heavy metals from water. Of course, you should wash it well before consuming the leaves.

Botanists now call it Nasturtium officinale, after a few years of suffering through the Latin Watercress, Water Cress, Nasturtium officinale, Rorippa nasturtium-aquaticumname Rorippa nasturtium-aquaticum. It is not to be confused with our garden nasturtium with its bright orange and yellow flowers. That plant, Tropaeolum majus hails from the Andes, and borrows  its common name from the Latin name of watercress, given their similar flavors, though they are unrelated in every respect. The essential oil in watercress leaves have organosulphur compounds that give them their bite and distinctive flavor.

It is impossible to determine where this plant originates. It occurs in virtually every country with cool fresh, running water. It was observed in America as early as 1630, and was likely already here before Europeans arrived. Here is a plant that defies all cultural and geographic barriers and blurs the line between food and medicine.

Copyright 2013 Steven Foster. Photos created 19 October 2013, Spring Creek, Rockbridge, Missouri

Derived from Eureka Nature column, 24 October 2013, Eureka Springs Independent Newspaper

Images of the Petra Siq

By Steven Foster

Here’s a link to 96 images I took along the Siq at Petra. The Siq is a narrow gorge split between mountains forming the main passage into the Nabataean city of Petra, a UNESCO World Heritage site in Jordan. Along the way one sees an impressive carved water channel and carved symbols of Nabataean gods. The natural sandstone is of spectaular beauty. Petra is an ancient city believed built by Nabataean Arabs around the 300 B.C.E., though remains of a neolithic settlement 10,000 years old are found at this extraordinary site where local Bedouin tribes lived among the ruins into the 1980s.