SALICACEAE. — POPULUS 31 



f Populus Jacquemontiana Dode in Mem. Soc. Hist. Nat. Autun, XVIII. 

 (Extr. Monog. Ined. Populus, 66, t. 12, fig. 108) (1905). 



INDIA. Bhutan. 



Through the kindness of the Keeper of the Herbarium of the Royal Gardens, Kew 

 three sheets of Haines' plant bearing the No. 826 have been loaned to the Arnold 

 Arboretum: one with fruits, collected June 1904, Labah ridge, alt. 2200 m.; an- 

 other with leaves, collected August 1904, Bhotan, without precise locality, alt. 

 2400 m. ; and the third with flowers only, collected April 1905, Pankasari ridge, 

 alt. 2700 m. In their shape and in the color of the upper surface the leaves resemble 

 those of P. Wilsonii Schneider, and are up to 20 cm. long and 18.5 cm. broad, the 

 petioles being up to 13.5 cm. long. The color of the under surface of the leaves is 

 glaucous, not whitish as in the dried leaves of P. Wilsonii, but the scarce pubescence 

 is almost the same in both, while in P. lasiocarpa Oliver even the mature leaves of 

 cultivated plants are hairy along the midrib and the main veins beneath. The 

 flowers of P. glauca are mostly bi-sexual, as indicated by Haines, otherwise the 

 perianth and the ovaries scarcely differ from those of P. Wilsonii, the perianth 

 of which is mostly not so largely developed and so deeply lobed as in P. glauca. 

 In this species the stigmas seem to be a httle shorter-stalked, but as far as I can 

 judge from the material before me all these characters of the flowers are too vari- 

 able to represent good distinguishing features. The fruits of P. glauca are roundish 

 and apparently a little more pubescent or villose than those of P. Wilsonii. Both 

 species need further study. 



5. Populus lasiocarpa Oliver. See p. 17. 



Sect. 3. TACAMAHACA Spach, Hist. Veg. X. 392 (1841). 



Populus, subgen. Eupopulus Dode, sect. Tacamahacae Dode in Mem. Soc. 

 Hist. Nat. Autun, XVIII (Extr. Monog. Ined. Populus, 14 et 34) (1905). 



Folia ramulorum turionumque inter se pleraque variabilia, subtus distincte dis- 

 coloria, albescentia, superne stomatibus plus minusve numerosis^ v. nullis praedita, 

 basi glanduhfera; petioH longitudine variabiles. Disci florum persistentes, margine 

 lobati v. crenati; stigmata 2-4, stylis brevibus v. nullis; stamina 18-60, antheria 

 oblongis v. subglobosis, baud apiculatis. Capsulae variabiles. 



6. Populus ciliata Wallich apud Royle, III. Bot. Himal. I. 346; II. t. 84" or 98, 

 fig. 1 (1839). — Wesmael in De Candolle, Prodr. XVI. 2, 329 (1868); in Mem. Soc. 

 Sci. Hainaut, III. 63 [Monog. Populus) (1869). — Brandis, Forest Fl. Brit. Ind. 

 475 (pro parte) (1874); Ind. Trees, MO (pro parte) (1906). — Stewart, Punjab PI. 

 204 (1869). — Hooker f., Fl. Brit. Ind. V. 638 (1888). — Collett, Fl. Siml. 481 

 (1902). — Dode in Mem. Soc. Nat. Hist. Autun, XVIII. (Extr. Monog. Ined. 

 Populus, 65) (1905). — Haines in Jour. Linn. Soc. XXXVII. 407 (1906). — Gom- 

 bocz in Math. Termesz. Kdzl. XXX. 116 (Monog. Gen. Populi) (1908). — Henry 

 in Elwes & Henry, Trees Gr. Brit. & Irel. VII. 1840, in adnot. (1913). 



INDIA. Western Himalaya to Bhutan : Kumaon, northern face of Choor, 

 R. Blinkworth (No. 2796 of Wallich's Cat., type; with ripe fruits) ; Srinaghur, Kam- 

 rup (No. 2796 B of Wallich's Cat.); Nain-tdl, alt. 2100 m. Strachey & Winterbottom 

 (No. 1); northwest Himalaya, without locahty (Lachen?), 2000-3000 m., T. 

 Thomson; Sikkim, without locality, 2-3000 m., /. D. Hooker; Chakrata, alt. 2300 

 m., June 26, 1912, K. Narayana Jyengar (a loftj^ tree with gray, smooth bark; 

 common in blanks in Deodar forests); same locality, May 5 and June 25, 1912, 



' According to Gombocz the plants of this section have no stomata on the upper 

 surface of the leaves. 



