and Old World Birches. 185 



Betula microphylla. 



Professor Sargent has recently referred"^ to the fact that the 

 writer identifies the common brown-barked tree or half-shrub 

 of the Rocky Mountains with Bnnge's Betida riiicrophylla 

 described from the Altai of central Asia. Professor Sargent, 

 however, was unwilling to identify the American tree with 

 Bunge's species, and he accordingly proposed for it the new 

 name B. fontinalis. But a further comparison of B, fon- 

 tinalis and an authentic branch from the Altai of Bunge's 

 species sent from the Imperial Herbarium of St. Petersburg 

 to the Gray Herbarium, some of the original Tyan Shan mate- 

 rial of Kegel's B, cdha, subsp. soongorica\ in the Gray Her- 

 barium and in the United States [N'ational Herbarium, the 

 figures of Kegel's B. fruticosa^ var, cuneifolia^X and lastly 

 the original detailed full-page description by Bunge of his 

 B. inicrophylla^% has more firmly convinced the writer that 

 all three of these trees described from the Altai and the Tyan 

 Shan ranges are one species, B. microphylla, Bunge ; and that 

 this species differs from B. r hoinb if olia^^wii.^B. occidentalism 

 Nutt. and of many other authors, not Hook. B. fontinalis^ 

 Sargent) only in growing among the mountains of central 

 Asia rather than among those of northwestern America. 



A comparison of Bunge's original description of Betida 

 microphylla with JN^uttall's description of his B. occidentalis^l 

 the tree subsequently called by Sargent B. fontinalis, shows 

 no definite character of leaves, strobiles, samaras, nor twigs 

 upon which the two may be separated ; and Bunge's words, 

 " epidermide trimci flavescente neque alba, primo intuito dis- 

 tinctissima,"T[ are certainly not inapplicable to the small tree of 

 northwestern America described in tlie Botany of California 

 " with close dark-colored bark (at length light brown)."^"*^ Fur- 

 thermore, if ^ve compare with the branch of B. microphylla 

 sent from St. Petersburg to the Gray Herbarium the original 

 specimen of Kuttall's B. rho7nhifolico\-\ (preserved in the Gray 

 Herbarium and referred by Sargent to B. fontinalis), and 

 such specimens as Macoun's from the ISTorth Saskatchewan and 

 Dawson's from the Columbia River (Herb. Geol. Surv. Can., 

 :N'os. 23,620, and 23,621) or F. W. Anderson's material from 

 McCarthey Mts., Montana (U. S. Xat. Herb. I^o. 25,261), we 

 shall be perplexed to make out points of distinction. If we 

 also compare with some of the original material of Regel's 

 B. alba, subsp. soongorica, /S microp)hylla from 5,000 ft. in 



* Bot. Gaz. xxxi, 239. 



t Bull. Soc. Imp. Nat. Mosc. (1868) vi— repr. Enun. PL Semenow. (1869)99. 



X Regel, Mon. Bet. (1861) 35. t. 7. figs. 16-23. 



i^ St. Petersb. Mem. Savans Etrang. ii (1835) 606— reprint, Fl. Alt. Suppl. 84. 



f Nutt., Svlva. i, 22, t. 7 (1842). 1 Bunge, 1. c. 



** Watson, Bot. Cal. ii, 79. ff Nutt., 1. c. 24, t. 8. 



