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with large, orbicular, eleven-divided leaves. These are planted 

 in masses at the edge of groves or against walls. There are some 

 genera represented by good-sized trees, which in America are 

 small and chiefly southern, such as Illicium and Styrax, arid 

 others not native in America at all, such as ginkgo and camphor. 

 The latter reaches a diameter of more than a meter, and has a 

 close but flaky gray mossy bark, a wide-spreading crown, and 

 elliptical acute leaves five cm. long. The huge historic ginkgo 

 tree, which furnished the material for the discovery of motile 

 male gametes, is one and a half meters in diameter, and at the 

 time of our visit was bearing a good crop of the plumlike fruit. 

 There is an immense variety of other gymnosperms, mostly 

 unlabeled, and many deciduous trees entirely unknown to us. 



As weeds in or around the garden, there are several species 

 occurring also in America, as Erigeron canadensis, Plantago major, 

 Trifolium repens, and a smartweed, either Polygonum acre or 

 something very much like it. Under the forest cover a day- 

 flower, Commelina, is very common, with a small grass, like an 

 Echinochloa on a small scale, a little mint resembling a Satureja, 

 and a liliaceous plant like a Solomon's Seal, but blooming at the 

 apex first, with white and red flowers five cm. across. Most 

 striking of all the herbaceous plants are Phryma leptostachya and 

 Polygonum filiforme Thunb. The former is of course just like 

 its American form. The smartweed has the general habit of 

 its American analog, P. virginianum, with broad clustered leaves 

 and a slender raceme. Its fruit is also of the same structure and 

 explosive at maturity, but is red instead of green. The two 

 species grow side by side in great profusion, just as they do in 

 moist woods in the eastern United States. 



The numerous identical or parallel species, the familiar generic 

 names, and the vegetational similarity all combine to make real 

 the close relationship of the floras of Japan and of eastern Amer- 

 ica, and to show in a striking way something of the present 

 -distribution of the arcto-tertiary flora. It was especially obvious 

 that most of the native trees had smooth bark. Since the mild 

 climate of modern Japan is something like that of the Miocene 

 period, it is entirely possible that the arcto-tertiary vegetation of 

 that time was typically smooth-barked. 



