BETULACEAE. — BETULA 461 



Betula japonica Siebold, var. mandshurica Winkler in Engler, Pflan- 

 zenr. IV.-61. 78 (var. mandschurica) (1904). — Nakai in Jowr. Coll 

 Sd. Tokyo, XXXI. 202 (Fl Kor. 11.) (1911). 



Betula alha, subspec. mandshurica Regel in Pull Soc. Nat. Mosc. XXXVIII. 

 pt. 2, 399, tab. 7, fig. 15 (1865); in De CandoUe. Prodr, XVI. pt. 2, 165 



<1868). 



Betula alba, var. vulgaris Franchet in Jour, de Bot. Xlil. 206 (1899). — Burkill 



in Jour. Linn. Soc. XXVI. 497 (1899). 

 Betula mandahurica Nakai in Tokyo Bot. Mag. XXIX. 42 (pro parte) (1915), 



Western Szech'uan: west of Tachien-lu, Cheto-shan alt. 2800- 

 3400 m., woodlands, September 1908 (No. 983; tree 10-20 m. tall, 

 girth 1.2-2.4 m., bark white; fruits); same locality, alt. 2800-3700 

 m., September 1910 (No. 4088; tree 10-25 m. tall, girth 1.5-2.4 m.; 

 bark gray); northeast of Tachien-lu, Ta-p'ao-shan, alt. 2800-3400 m., 

 July 9, 1908 (No. 983%- tree 10-20 m. tali, girth 1.2-2.4 m., bark white; 

 young fruits); near Monkong Ting, alt. 2800-3400 m., woodlands, 

 June 1908 (No. 983^; tree 10-20 m. tall, girth 1.2-2.4 m., bark white; 

 unripe fruits); around Suligpan, alt. 2800-3700 m., woods, August 

 1910 (No. 4636; tree 7-13 m. tall, girth 0.9-1.8 m., bark white; sterile); 

 around Tachien-lu, P. Soulie (No. 566, fide Franchet) ; without precise 

 locality, forests, altitude 2300 m., August 1903 (Veitch Exped. No. 

 4494; tree 10 m. tall, bark white; fruits). 



NORTHEASTERN ASIA. Ussuri: Olga Bay, Fr. Schmidt (type, ex Regel). 

 Korea: "Kyong-san, in monte Chiri-san," summer 1905, Shlki (fide Nakai). 



This Chinese White Birch seems geographically well separated from the other 

 forms of B. japonica Siebold, and I am not quite sure whether it is the same as 

 Regel's form. The only real difference 1 can detect are the very glabrous leaves, 

 which Regel gives as a character for his subspecies. 



From the European and western Asiatic Betula pendula Roth {Betula alha Lin- 

 naeus pro parte; Betula verrucosa Ehrhart), wnich also has quite glabrous leaves, 

 the Chinese form differs in the shape and especially in the short and regular denta- 

 tion of the leaves as well as in the shape of the fruiting bracts, which, however, is 

 variable. 



On the extreme west and northwest of Szech'uan at high elevations this is a com- 

 mon tree, but 1 only saw it scattered through mixed forests in which coniferous 

 trees predominated. However, I was told of vast forests of this Birch to the im- 

 tnediate west and south of Sungpan Ting. The bark is used for lining straw hata 

 and is an article of much value locally; it is used in great quantity in the district of 

 Shuang-hu Hsien on the Chengtu Plain. In general appearance the Chinese 

 White Birch resembles the North American B. papyri/era Marshall, but the bark 

 IS more persistent and not so white. Pictures of this tree will be found under 

 No. 178 of the collection of my photographs and also in my Vegetation of Western 

 China, No. 133. E. H. W. 



