480 WILSON EXPEDITION TO CHINA 



(1911); in Tokyo Bot. Mag. XXIX. 44 (1915). — Schneider, III. Handb. Lauh- 

 holzk. II. 48S, fig. 553 l-m, 554 a-b (1912). 



Betula exalata S. Moore in Jour, Liun. Soc. XVII. 386, t. 16, fig. 8-10 (1879). 

 Betula chinensiSf var. angusticarpa Winkler in Englcr, PJlanzenr. IV.-61j 67, 

 fig. 19K-L(1904). 



CHINA. Chili: Weichang, 1910, W, Purdom (No. 85; bush 1.8-3 m. tall; 

 flowers and old cones); Pohua-shan, near top of Mt. Conolly, alt. 1600-lSOO 

 m., July 1S77, E. Bretschneider (type, ex !Maximowicz). 



NORTHEASTERN ASIA. Mandshuria: Chien-shan, June 4, 190G, i?'. N, 

 Meyer (No. 90; fruits); same locality, alt. 300 m., F. Ross (No. 223, 428, 478, 553; 

 type of B. exalata, ex Moore and Burkill) ; prov. Mukden (ex Komarov). Korea: 

 " Districtus Mu-sang, Trajectus Czao-rieng, Fluvium Tumingan," May 23, 1897, 

 V, Komarov (flowers); "in montibus Nai-piang, supra 1000 m.," August 1901, 

 U. Faurie (No. 605; fruits); ** in montibus Hoang-hai-to," August 1906, U, 

 Faurie (No. 203; fruits); "in monte dcs diamants," June 24, 1906, U". Faurie 

 (No. 204; young fruits). 



Forms of this species sometimes much resemble B, davurica Pallas, which, as 

 far as I have seen, has the young branchlets always more or less covered with 

 glands, but otherwise they are glabrous or sparsely pilose, not silky-villose, as m 

 B. chinensis. In the specimen distributed by U. Faurie under No. 204 the leaves 

 are very similar to those of B. davurica Pallas, but the middle lobe of the fruiting 

 bracts is as long as in tj-pical B. chinensis and the pubescence of the young parts 

 is the same. See also under B. davurica Pallas. 



I do not know Betula collina Nakai (in Tokyo Bot. Mag. XXIX. 44 [1915]} 

 from northern Korea, " in Colle Ungil." According to the description it must be 

 very similar to B. chinensis Maximowicz. 



Sect. 3. HUMILES W. D. Koch, Syn. Fl Germ. Helv. ed. 2, 761 (1843). — Prantl 

 in Engler & Prantl, Nat. Pflanzenfam. HI. abt. 1, 45 (1887). — Koehne, Deutsche 

 Dendr. 107 (1893). — Schneider, III. Handb. Laubholzk. 1. 103 (1904). 



Betula, sect. Nanae Regel in Bull. Soc. Nat. Mosc. XXXVIIL pt. 2, 407 

 (1865). 



To this section belong also different American species. Several of the forms 

 referred here need a careful investigation. 



Subsect. a. Nanae Schneider, n. comb. 

 Betula, sect. Eubetula, subsect. Nanae Regel in De CandoUe, Prodr. XVI. 

 pt. 2, 162 (pro parte) (1868). — Winkler in Engler, PJlanzenr. 1V.-«1, 

 69 (pro parte) (1904). 



20. Betula nana Linnaeus, Spec. 983 (1753). —Regel in Bull. Soc. Nat Mosc. 

 XXXVIII. pt. 2, 407 (1865); De Candolle, Prodr. XVI. pt. 2, 171 (1868).-- 

 Dippel, Handb. Laubholzk. 11. 181 (1892). — Herder in Act. HorL Petrop. All- ou 

 (1892). — Koehne, Deutsche Dendr. 112 (1893). — Hempel & Wilhelm, ■^«^'"f * 

 Strducher, II. 26, fig. 132 E-H (1894). —Schneider, III Handb. Laubholzk. 1. lUo» 

 fig. 55 f-i (1904). — Winkler in Engler, Py^anzenr. 1V.-61, 69, fig. 20 D-F (1904). 

 Ascherson & Graebner, Syn. Mitteleur. Fl. IV. 406 (1911). — Marshall m Moss, 

 Cambridge Bnt. FL 11. 86, t. 88 (1914). 



Alnus nana Clairville, Man. d'Herb. 280 (1811). 

 Chamaebetula nana Opiz in Lotos Jahrb. Nat. V. 259 (1855). 

 Betula nana, var. genuind Regel, in Nouv. Mem, Soc. Nat. Mosc. XIII. pt. > 

 101, t. 9, fig. 1-8, 13 (Monog. Betulac. 43) (1861). 



