Familiar flora in a foreign land

It is a typical fall October day in the south. Strolling along a forested mountain trail, an invigorating breeze makes the fall colors dance in the sunlight. Recognizing the familiar leaf of a sweet gum burnished red, the fragrance of crushing a nearby sassafras leaf, or the emergence of the yellow spider-like autumn blooms of witch hazel evokes the joys of a stroll through the southern woods. Ah, the wonders of the Ozark forest -- or are these mountain forests in temperate eastern China?

If you start digging a hole in rich woods in an Ozark forest, then keeping digging until you again see the light of the day on the other side of the world, you may be surprised to see that the plants look very much like those here.

With the discovery of American ginseng (Panax quinquefolius) in 1716 by Joseph Francois Lafitau (1681-1746), a Jesuit missionary who had come to America in 1711 to work among the Mohawks above Montreal, botanists became aware of floristic similarities between eastern Asia and eastern North America.

The first Westerner to describe and depict Chinese ginseng (Panax ginseng) in a 1714 publication was Petrus Jartoux (1668-1720) a Jesuit missionary in North China. He described the range and habitat of ginseng in China, concluding, "All of which makes me believe, that if it is to be found in any other country in the world, it may be particularly in Canada, where the forest and mountains, according to the relation of those that have lived there, very much resemble these here."

Based on this hunch, two years later his Jesuit colleague, Lafitau, discovered American ginseng. This pattern of discontinuities in plant geography is called the interrupted Eastern Asiatic-Eastern North American disjunct range.

From these serendipitous beginnings, over the next 200 years botanists documented dozens of similarities involving 150 plant groups found only in eastern Asia and eastern North America. Most of these plants, including wildflowers, shrubs and trees are representatives of relatively primitive plant families that evolved in what is now southeastern China, and millions of years ago migrated to much of the northern hemisphere. Mountain building processes in western North America, Europe and elsewhere, along with Pleistocene glaciation, among other factors, isolated these plant groups in the eastern part of their respective continents. And so, a stroll in forests just outside my current location in Beijing, China, evoke an eerie familiarity amidst all that is foreign.