ACERACEAE. — ACER 95 
woods, abundant, alt. 1800-2100 m., May and September 1907 (No. 
274, in part); Hsing-shan Hsien, woods, abundant, alt. 1500-2100 m., 
May 19 and October 1907 (Nos. 274, in part, 430); Kuan Pao, Chang- 
yang Hsien, woods, alt. 1200-1800 m., December 1907 (No. 683, in 
part, fruits); Patung Hsien, woods, alt. 1500-1800 m., May 1907 
(No. 274, in part); South Wushan, woods, common, alt. 1200-1800 m., 
May 11, 1907 (No. 274, in part). 
Part of No. 274 represents A. tetramerum, var. lobulatum Rehder (in Fedde Rep. 
Nov. Sp. I. 174 [1905]) which passes gradually into the type and is perhaps better 
considered only a slightly different form. "This and the type are restricted to 
Hupeh. The specimens of Szech'uan differ in their leaves being generally ovate to 
ovate-oblong in outline, not or only very slightly lobed and usually 3-nerved at 
the base. In regard to other characters they show marked differences, and the 
following three varieties can be distinguished. 
Acer tetramerum, var. betulifolium Rehder, n. var. 
Acer betulifolium Maximowiez in Act. Hort. Petrop. XI. 108 (1890). 
Western Szech'uan: Sungpan, woodlands, alt. 2400-2800 m., 
August 1910 (No. 4511); southeast of Sungpan, alt. 3000-3200 m., 
August 1910 (4512); Wa-ssu country, Wén-chuan Hsien, alt. 1800- 
2400 m., July and September 1908 (No. r9or); alt. 2100-2500 m., 
October 1910 (No. 4102). Kansu: banks of the river Lumbu, south 
of Mt. Chagolo, July 11, 1885, S. N. Potanin. Northern Shensi: 
G. Giraldi (Nos. 2118, 2119, 7137, in herb. Florence). 
With the recent material collected by Wilson in northwestern Szech'uan at 
hand I have come to the conclusion, that A. betulifolium cannot be separated 
specifically from A. tetramerum. Sungpan is situated only about 80 miles south- 
west of the type locality and Wén-chuan Hsien about 100 miles south of Sung- 
pan, so that apparently the variety betulifolium is restricted to the northwestern 
part of the range of the whole species. It is chiefly distinguished from the type 
by its ovate or oblong-ovate leaves, not or only very slightly lobulate, glabrous or 
glabrescent and usually three-nerved at the rounded or sometimes cuneate base 
and by the broader wings of the fruits. 
Acer tetramerum, var. betulifolium f. latialatum Rehder, n. forma. 
Recedit a varietate praecedente praecipue racemis elongatis ad 18 
em. longis et alis latioribus leviter introrsum falcatis, ad 14 mm. latis. 
Western Szech'uan: southeast of Sungpan, woodlands, alt. 
2400-3000 m., August 1910 (No. 4104, in part). : 
A very striking plant in fruit with its long pendulous racemes and broad wings. 
Acer tetramerum, var. elobulatum Rehder, n. var. 
Acer tetrameram Rehder in Sargent, Trees and Shrubs I. 171, t. 85 (in part as 
to the Szech’uan specimens and fig. 7) (1905). 
