vi INTRODUCTION 



a continental species which just reaches Japan and this is true of the Chinese 

 White Pine (P. Armandi Franch.) now known to grow spontaneously on the 

 southern islands of Tanega-shima and Yaku-shima. This species also grows in 

 Formosa. The dwarf P. pumila Regel has a wide range of distribution in north- 

 eastern Asia as well as on the mountains of Japan from central Hondo north- 

 ward. Of the Spruces only Picea jezoensis Carr. is actually known to grow on the 

 mainland of eastern Asia, although it is probable that the species growing in 

 Korea and now referred to P. Schrenkiana Fisch. & Mey. is not that species 

 but is the same as the newly discovered P. Koyamai Shiras. Larix dahurica, 

 var. japonica Maxim, apparently reaches the continent and it is doubtful if this 

 is really different from the type species. The other Japanese members of the sub- 

 family Abieteae are endemic. 



The subfamily Taxodieae is represented by the endemic Sciadopitys verticillata 

 S. & Z. and by Cryptomeria japonica D. Don. The latter tree was discovered 

 on the Chusan Islands in China by James Cunningham in 1701, but it is doubt- 

 ful if it is really indigenous anywhere outside of Japan. Of the subfamily 

 Cupresseae, Chamaecyparis obtusa S. & Z. also grows in Formosa and Thuja Stan- 

 dishii Carr. in Korea. Except Juniperus conferta Pari, and the little known J. 

 procumbens Sieb. no species of Juniper is peculiar to Japan, although the var. nip- 

 ponica of J. communis L. and var. Sargentii of J. chinensis L. must be so considered 

 in the present state of our knowledge of these plants. Of the Japanese Taxaceae 

 none is endemic. Torreya nucifera S. & Z. grows on the island of Quelpaert off the 

 coast of southern Korea but is otherwise confined to Japan. Taxus cuspidata 

 S. & Z. grows in Korea and in eastern Siberia and is represented in China and 

 Formosa by the var. chinensis Rehd. & Wils. Cephalotaxus drupacea S. & Z. reaches 

 central China but is more generally represented there by the var. sinensis Rehd. 

 & Wils. The two species of Podocarpus also grow in the Liukiu Islands and in 

 Formosa. The Ginkgo is planted in Japan as in China and is probably unknown 

 in the wild state. Three Chinese trees (Cunninghamia lanceolata Hook., Cupressus 

 funebris Endl. and Thuja orientalis L.) are sparingly planted in temple grounds 

 and gardens in Japan but are uncommon and since they are not indigenous all 

 further reference to them in these pages will be omitted. 



In Japan the distribution of many conifers is clearly defined and often limited. 

 Of the Abieteae only Picea jezoensis Carr., Pinus parviflora S. & Z. and Pinus 

 pumila Regel are common to Hondo and Hokkaido though it is possible that 

 Pinus densiflora S. & Z. may grow on these two islands. Of the other Pinaceae 

 which grow in Hondo only Juniperus conferta Pari, and J. chinensis, var. Sar- 

 gentii Henry grow also in Hokkaido. The two species of Podocarpus are con- 

 fined to the warm parts of Shikoku and Kyushu in the south; the Torreya is only 

 questionably wild north of latitude 36, but the Cephalotaxus is common as far 

 north as central Hokkaido and Taxus cuspidata S. & Z. is also found in the Kuriles 

 and in Saghalien. The circumpolar Juniperus communis L. just reaches northern 

 Hokkaido and is found also in the Kuriles and in Saghalien; the var. montana 

 Ait. is found in Saghalien. These two Junipers are the only American and Euro- 

 pean conifers found within the limits of the Japanese Empire. 



In the case of many species it is clearly demonstrated that climate is the all- 

 important factor in limiting the distribution of conifers in Japan, yet it cannot 

 be claimed that this has anything to do with the absence of such hardy trees as 

 Picea jezoensis Carr. and Larix Kaempferi Sarg. from Hondo north of the Nikko 

 region. Again, it is curious that no Larch is indigenous in Hokkaido, yet Larix 



