BETULACEAE. BETtJLA 465 



Strobili sacpe nutantes et subcylindrici ; samararum alae nueula 

 aequilatae v. saepe latiores. Folia ut videtur satis breviter et 



anguste dentata 22. B. Middendorjjii. 



ft Amenta fructifera pcndula v. in 25. B. davurica suberecta, cylindrica v. 



subelliptica. Folia saepe mediocra, majora plus quam 5 cm. longa (v. 

 petioli 1 cm. longi v. longiores, v. amenta cylindrica et pendula), apice 

 plus minusve acamiaata v. sub triangul aria, nervis utrinque (4.-)5-7 



(-8). Arbores Sect. 4. EXCELSAE. 



Folia ovata v. ovato-oblonga, basi cuneata v. cuneato-rotunda. Strobili 

 suberecti, elliptici v. subcylindrici; bractearum lobus medius saepis- 

 sime distinctus angustusque lateralibus suberectis v. patentibus inter- 

 dum paulo recurvis longior; samararum alae nucula 3^ angustiores v. 

 rarius subaequilatae. Cortex trunci junioris gnseo-brunneus v. ex 

 parte flavua v. rubescens, lamellis laxis secedens. 



Subsect, a. Dahuricae. 



25. B. davurica. 

 Folia triangularia v. ovato- v. rhombico-triangularia. Strobili penduli v. 



subpenduli; bractearum lobi laterales fere semper margine supcriore 

 recurvatis, satis latis, lobus medius brevis, basi dilatatus comparate 

 satis reductus; samararum alae nucula aequilatae v. usque duplo 

 latiores , Subsect. b. Albae. 



26. B. japonica. 



F *- 



ENUMERATIO BETULARUM ASIAE ORIENTALIS 



NEC NON HIMALAYAE. 



Sect. 1. ACUMINATAE Kegel in Bull. Soc. Nat. Mosc. XXXVIIl. pt. 2, 



418 (1865). — Prantl in Engler & Prantl, Nat. Pflanzenfam. III. Abt. 1, 45 

 (1887).— Schneider, III. Handh. Laubholzk. I. 97 (1904), II. 882 (1912). 



Belulasier Spach in Ann. Sci. Nat. ser. 2, XV. 198 (1841). 



Belula, subg. Beiulaster Endlicher, Gen. Suppl. IV. 20 (1847). 



Belula, sect. Beiulaster Kegel, subsect. Acuminatae Kegel in De Candolle, 



Prodr. XVI. pt. 2, 179 (1864). — Winkler in Engler, Pflanzenr. 1V.-61, 88 



(1904). 



This section is well distinguished by the rather small and narrow bracts of the 

 fruiting catkins and by the broad winged seeds. The bracts of B. Maxiniowicziana 

 Kegel only are somewhat like those of the other sections. The fruiting catkins are 

 racemose or solitary', narrow-cylindric, long and pendulous. 



1. Betula Maximowicziana Kegel in De Candolle, Prodr. XVI.pt. 2, 180 (18G8). — 

 Franchet & Savatier, Enum. PL Jap. I. 4.56 (1875). — Shirai in Tokyo BoL Mag, 

 VIII. 321, t. 6, fig. 36-38 (1894). — Sargent, Sllva N. Am. IX. 48 (1896). — Shira- 

 sawa, Icon. Ess. For. Jap. I. 45, t. 23, fig. 1-8 (1900). — Mayr, Fremdl. Wald- & 

 Parkbaume, 449, fig. 108 (1906). 



Belula Maximowiczii Kegel in Ball. Soc. Nat. Mosc. XXXVIII. pt. 2, 418, t. 6, 

 fig. 1-8 (non Kuprecht) (1S65). — Kehder in Bailey, Cycl Am. Hort. 1. 158 

 (1900). — Schneider, III. Handh. Laubkolzk. 1. 97, fig. 53 c, 54 c-c* (1904); 

 II. 882 (1912). — Winkler in Engler, Pflanzenr. IV .-61, 89, fig. 22 D-F 

 (1904). — Henry in Elwes & Henry, Trees Gr. Brit. & Irel. IV. 976, t. 209, 



