30 WILSON EXPEDITION TO CHINA 



decidui, distincte lobati; stigmata 3, stylosa; stamina, circiter 12, antheris longis, 

 apice apiculatis. Capsulae elongatae, pedicellatae. 



1. Populus euphratica Olivier, Voy. Emp. Othoman. III. fig. 45-46 (1807). — 

 Wesmael in Mem. Soc. Sci. Hainaut, III. {Monog. Populus, 54, t. 10-13) (1869). — 

 Brandis, Forest Fl. Brit. Ind. 474, t. 63 (1874). — Hooker f., Fl. Brit. Ind. V. 638 

 (1888). — Burkill in Jour. Linn. Soc. XXVI. 536 (1839). — Dode in Mem. Soc. 

 Hist. Nat. Autun, XVIIl. {Extr. Monog. Ined. Populus, 16, t. 11, fig. 1, 1% 1=, l^) 

 (1905). — Gombocz in Math. Termesz. Kozl. XXX. 68 {Monog. Gen. Populi) (1908). 



Populus diversifolia Schrenk in Bull. Acad. Sci. St. Petersbourg, X. 253 (1842); 



in Fischer & Meyer, Enum. Alt. PI. Nov. Schrenk. 15 (1842). — Trautvetter, 



PI. Imag. Fl. Russ. 23, t. 16 (1844). — Dode in Mem. Soc. Hist. Nat. Autun, 



XVIII. {Extr. Monog. Ined. Populus, 15) (1905). 

 Balsamiflua deltoides Griffith, Icon. PI. Asiat. IV. t. 526 (1854). 

 Populus Ariana Dode in Mem. Soc. Hist. Nat. Autun, XVIII. {Extr. Monog. 



Ined. Populus, 16) (1905). 

 Populus Litwinowiana Dode, 1. c. 17 (1905). 



CHINA. Chili, Peking, R. Alcock (fide Burkill); Kanou, beyond the Great 

 Wall, P. J. Piasezkei (fide Maximowicz). Also in northern Africa and western 

 and central Asia. 



I doubt, however, if Alcock's specimen from Peking belongs to this species. 



2. Populus pruinosa Schrenk in Bull. Acad. Sci. St. Petersbourg, III. 210 (1845). 

 Wesmael in Mem. Soc. Sci. Hainaut, III. {Monog. Populus, 56, t. 14) (1869). — 

 Dode in Mem. Soc. Hist. Nat. Autun, XVIII. {Extr. Monog. Ined. Populus, 18, 

 t. 11, fig. 2») (1905). — Gombocz in Math. Termesz. Kozl. XXX. 72 {Monog. Gen. 

 Populi) (1908). 



Populus glaucicomans Dode in Mem. Soc. Hist. Nat. Autun, XVIII. {Extr. 

 Monog. Ined. Populus, 18, t. 11, fig. 2) (1905). 



TURKESTAN, SOUTHWESTERN SIBERIA. 



According to the photographs and notes taken by the well-known explorer F. N. 

 Meyer on February 19, 1911 in Chinese Turkestan for the Department of Agricul- 

 ture of the United States, P. pruinosa may be distinguished from P. euphratica 

 by the bark of old trunks. Meyer's photograph No. 5685 shows a trunk of P. 

 pruinosa with a distinctly and deeply grooved bark as in Ash and Elm trees, while 

 the photograph No. 5689 represents P. euphratica with a more or less shaggy bark. 



Sect. 2. LEUCOIDES Spach, Hist. Veg. X. 385 (1841). — Gombocz in Math. 

 Termesz. Kozl. XXX. 118 {Monog. Gen. Populi) (1908). 



Populus, subgen. Eupopulus Dode, sect. Leucoideae Dode in Mem. Soc. Hist. 

 Nat. Autun, XVIII. {Extr. Monog. Ined. Populus, 14 et 35) (1905). 



Folia ramulorum turionumque vix diversa subtus plus minusve discoloria, basi 

 glandulif era, superne stomatibus non praedita ; petioli basi cyhndrica, apice paulo 

 compressi, semper satis longi. Gemmae vix viscosae. Disci florum persistentes, 

 satis evoluti, fere ad basim lobati; stigmata 2-3, stylis elongatis; stamina 30-40, 

 antheris longis, apice apiculatis. Capsulae crassae, pedicellatae (an semper?), 

 villosae. 



3. Populus Wilsonii C. Schneider. See p. 16. 



4. Populus glauca Haines in Jour. Linn. Soc. XXXVII. 408, fig. (1906). — Gom- 

 bocz in Math. Termesz. Kozl. XXX. 157 {Monog. Gen. Populi) (1908). 



