THE ROMANCE OF OUR TREES-II, THE GINKGO 



ERNEST H. WILSON 



Assistant Director, Arnold Arboretum 



The Oldest Cultivated Nut Tree, Now Rapidly Coming into Popular Favor 

 as an Ornamental on Account of its Wide Adaptability, Hardiness, Free- 

 dom from Disease and General Character. It Forms a Direct Link 

 with Life on the Earth That Was Extinct Even Before Man Appeared 



[Editor's Note: This series of articles which will be continued in successive issues, introduces a new note in dealing 

 with some of the best known and essential garden material. The purpose of these articles is to interpret the vivid stories that 

 plants tell of themselves and of the life of the world. Next month will tell the story of the Cedar of Lebanon.] 



|HIS sole survivor of an 

 extensive family once 

 rich in species and dis- 

 tributed over the tem- 

 perate regions of both North and 

 South Hemispheres in prehistoric 

 periods of the Earth's history, is 

 unique among existing trees. It 

 boasts a whole catalogue of pecu- 

 liarities and is not closely related 

 to any living family nor group in 

 the whole Vegetable Kingdom. 

 Its leaves, it is true, resemble the 

 pinnae of the common Maiden- 

 hair Fern; but its plum-like fruit 

 is not a fruit in the true botanical 

 sense of the term but a seed some- 

 what resembling that of the Cali- 

 fornian Nutmeg (Torreya calif or- 

 nica) or that of the Cycads; it is 

 fertilized by a motile sperm like 

 the Cycads, Ferns, and Club 

 Mosses; its shoots are of two 

 forms like those of the Larches, 

 and like them it loses its leaves 

 in autumn. 



But whilst it possesses these 

 points of similiarity with a num- 

 ber of plants it is closely related to none but constitutes 

 a family of its own which forms an obscure connecting link 

 between the Yew family, the Cycads, the Ferns and their 

 allies. It is hardy in New England as far north as Hanover, 

 New Hampshire, in Minneapolis, and in Canada, but does not 

 seem happy in north Pacific states; is unaffected by summer 

 droughts and thrives under city conditions as well as in the 

 pure air of the country; is not known to be attacked by any 

 pest, insect or fungoid, and lives to a great age. It transplants 

 readily when of large size, as a tree on Boston Common testi- 

 fies. The Japanese think nothing of moving trees 40 feet 

 tall and more than a foot in diameter of trunk. An avenue 

 of Ginkgo trees of this size was planted in 1914 on the boule- 

 vard leading from the terminal station in Tokyo and not one 

 died. However, in this connection it must be remembered 

 that Japan enjoys a more generous summer rainfall than 

 North America does. 



ESSENTIALLY A WELL-GROOMED TREE 

 An intimate view of the Ginkgo in Boston Public 

 Gardens, showing the clean-cut character throughout 



The fossil evidence is insufficient 

 to prove the existence of members 

 of the Ginkgo family in the age of 

 the Coal measures (Carboniferous 

 period) but there is a strong suspi- 

 cion of their presence in the next 

 (Permian or Triassic system) as 

 fossils from Virginia show. 



From the rocks of the Chalk 

 Age (Cretaceous) of North Amer- 

 ica, Greenland, and Vancouver 

 Island, species have been named 

 which are probably identical with 

 that living to-day. From the 

 Tertiary period fossils of several 

 species have been described from 

 widely separated parts of the 

 Northern Hemisphere and it may 

 be concluded with approximate 

 certainty that the present Ginkgo 

 biloba flourished at that period; 

 also that it was a common tree 

 in the present temperate circum- 

 polar regions of the whole North- 

 ern Hemisphere. 



TH E close of the Tertiary pe- 

 riod was marked by a glacial 

 epoch which, in Europe and North America in particu- 

 lar, destroyed much of the vegetation. In eastern North 

 America the ice-cap extended as far south as Philadelphia 

 (Lat.40°N.)as the scarred rocks, erratic boulders and detritus 

 amply testify. This ice-cap did not reach any part of China, 

 Korea or Japan proper, though of course the climate there 

 was very considerably modified by its influence. The glacia- 

 tion of North America, Greenland, Europe and western Si- 

 beria probably caused the extinction of the Ginkgo in those 

 lands, whereas in the Orient, thanks to the milder climate 

 which obtained, it survived. 



But to-day the Ginkgo, statements to the contrary not- 

 withstanding, no longer exists in a wild state, and there is no 

 authentic record of its having ever been seen growing spon- 

 taneously. Travellers of repute have searched for it far 

 and wide in Japan, Korea, Manchuria and China but none 

 has succeeded in solving the secret of its home. 



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