PINACEAE. TSUGA DIVERSIFOLIA 51 



yama, near Aomori, where it is fairly common as a small tree at altitudes between 

 700 and 1000 m. above the sea. On the upper wind-swept slopes of Hayachine- 

 san in Rikuchu province it is reduced to scrub and with Abies Mariesii Mast, 

 covers a great area between 1600 and 2000 m. altitude. On the same mountain, 

 but near its base, this Tsuga is a common tree in the forests with Abies Mariesii 

 Mast., Pinus parviflora S. & Z. and Thujopsis dolabrata, var. Hondai Mak. In the 

 Nikko region and on the northern slopes of Fuji-san, between 1500 and 2000 m. alti- 

 tude, this northern Tsuga reaches its maximum development and forms nearly pure 

 forests. At its lowest level on the mountains of these regions it is associated with 

 Abies homolepis S. & Z., and at its upper limits with Abies Veitchii Lindl., and 

 growing with it throughout its altitudinal range are such conifers as Larix Kaempferi 

 Sarg., Thujopsis dolabrata S. & Z., Thuja Standishii Carr., Picea jezoensis Carr., 

 Pinus parviflora S. & Z. and broad-leaved trees like Betula Ermanii Cham., B. 

 corylifolia Regel, B. Maximowicziana Regel, Sorbus japonica Hedl., S. commixta 

 Hedl., Alnus hirsuta, var. sibirica Schneid., Prunus ssiori Schmidt and Quercus 

 mongolica, var. grosseserrata Rehd. & Wils. On the upper middle slopes of the 

 volcanic Mt. Ontake Tsuga diversifolia forms with Abies Veitchii Lindl., Picea 

 jezoensis Carr. and with occasional trees of Pinus koraiensis S. & Z. extensive 

 forests. It forms forests also on the granite Tsubakura-dake in the same province 

 of Shinano. I did not meet with this Tsuga south of these alps of Shinano, but 

 I have before me a specimen collected on Sobo-san in Bungo province, Kyushu. 

 In this connection it is interesting to recall that the species was founded by Maxi- 

 mowicz on material collected in an alpine region of this southern island. Very 

 probably this tree occurs on many of the high mountains in Kyushu, Shikoku 

 and southern Hondo, but it is plentiful only on the Shinano mountains and 

 northward. 



Like T. Sieboldii Carr. this Hemlock selects steep, rocky slopes and is seen at its 

 best in rich moist forests. When the forests are mixed there is usually a dense 

 undergrowth composed of dwarf Bamboo, Rhododendron Metternichii S. & Z., 

 R. brachycarpum G. Don, Enkianthus campanulatus Nichols., Viburnum furcatum 

 Bl., V. urceolatum S. & Z. and Menziesia pentandra Maxim., but where the Tsuga 

 forms pure or nearly pure forests, as on Tsubakura-dake in Shinano, the upper 

 middle slopes of Nantai-san and elsewhere in the Nikko region there is no under- 

 growth whatever and the large roots of the Hemlock trees are exposed. 



At its best, as seen in the Nikko region, on Fuji-san and in the Shinano province, 

 Tsuga diversifolia is as large and as handsome as its southern relative T. Sieboldii 

 Carr., but generally it is a smaller tree. The largest I saw measured 26 m. tall 

 and had a trunk 4 m. in girth, but the average is from 16 to 22 m. tall and from 2 

 to 2.5 m. in girth of trunk, and on wind-swept slopes in northern Hondo it 

 becomes reduced to scrub from 1.5 to 2 m. high. The branches are slender, hori- 

 zontally spreading, very numerous and are retained low down on the trunk, and 

 the outline of the crown is more or less pyramidal. Although abundantly distinct, 

 in general appearance this species closely resembles T. Sieboldii Carr., the bark is 

 similar, the branching, more especially in young trees, is more dense and intricate, 

 the leaves are shorter, crowded on the twigs and less lustrous, the cone is smaller 

 and its peduncle is less apparent and the wood is perhaps denser; but all these 

 characters are relative and old trees of these two species are sometimes difficult to 

 distinguish. The winter-buds of T. diversifolia are pyriform to subglobose, flattened 

 at the apex and often puberulous; the shoots are pubescent and these characters, 

 particularly the latter, best distinguish the species. The short, gray pubescence 



