Betulaceae 



373 



6B. Shrub; leaves 1.5-4 cm. long; petioles 5-10 mm. long 9. B. apoiensis 



5B. Leaves broadly deltoid-ovate or narrowly so, distinctly broader below, smooth and more or less lustrous above, the teeth 



more or less spreading; petioles 5-35 mm. long; lateral nerves 7- to 12(-15)-pairccl 7. B. ermanii 



3B. Fruiting aments erect, sessile or subsessile, subglobose to oblong. 



9A. Leaves 1.5-4 cm. long, acute, with 4-8 pairs of lateral nerves; petioles 2-10 mm. long; shrub less tlian 1 m. high. 



lOA. Leaves usually acute at base, the lateral nerves 4—6 pairs; fruiting aments 1-1.5 cm. long, 3.5-7.5 mm. across; bracts 



equally 3-lobed, the midlobe slightly recurved at tip; boggy places 8. B. tateuiakiana 



lOB. Leaves usually rounded at base, the lateral nerves 6-8 pairs; fruiting aments 1-3 cm. long, 6-12 mm. across; midlobe of 



the bracts longer than the lateral ones, straight; rocky slopes 9. B. apoiensis 



9B. Leaves 4-10 cm. long, acuminate, with 8-15 pairs of lateral nerves; petioles 4-25 mm. long; fruiting aments 2-3.5 cm. long. 



IIA. Leaves broadly ovate; fruiting scales 13-15 mm. long 10. B. globispica 



IIB. Leaves narrowly ovate to more broadly so; fruiting scales 7-8 mm. long 1 1. B. grossa 



1. Betula maximowicziana Regel. B. candelae Koidz. hybrid between No. 3 and No. 6. Reported from Hokkaido, 

 Udai-kamba, Saihada-kamba. Tree with gray or orange- originally described from Kamchatka. 



gray bark peeling off into papery thin pieces, the branchlets 4. Betula davurica Pall. B. maackji Rupr. Ko-ono- 



red-brown, glabrous, lustrous; leaves broadly ovate to nearly ore, Yaegawa-kamba. Tree with gray-brown to gray bark, 



ovate-orbicular, 8-14 cm. long, 6-10 cm. wide, short-acuminate, the branchlets very resinous, pilose; leaves rhombic-ovate to 



deeply cordate at base, serrate, with glandular tipped teeth, narrowly ovate, 4-8 cm. long, acute or acuminate, irregularly 



scattered pilose while young above, slightly appressed pilose toothed, broadly cuneate at base, pilose on nerves beneath, the 



on nerves and later often becoming glabrous beneath, the lat- lateral nerves of 6 to 8 pairs, the petioles 5-15 mm. long, 



eral nerves of 10 to 12 pairs, the petioles 25-35 mm. long; slightly pilose; fruiting aments erect, short-pedunculate, 2-2.5 



fruiting aments 2-4 in a cluster, racemose, pedicellate, pendu- cm. long, narrowly oblong, the scales glabrous, lustrous, firm, 



lous, long-cylindric, (2-) 3-7 cm. long, 6-7 mm. in diameter; the midlobe deltoid, the lateral ones spreading, rounded, as 



fruiting scales glabrous, about 3 mm. long, 3-lobed, the lateral long as the midlobe; wings about half as wide as the nut. 



lobes ascending, shorter than the midlobe; nuts about 3 mm. Hokkaido, Honshu (centr. and n. distr.). Korea, Man- 

 long, the wings 2-3 times as wide as the body. May-June. churia, Ussuri, and Amur. 



Hokkaido, Honshu (centr. and n. distr.). s. Kuriles. Var. okuboi Miyabe & Tatew. Hidaka-yaegawa. Leaves 



2. Betula corylifoba Regel & Maxim. Neko-shide, with 7-9 pairs of lateral nerves; midlobe of fruiting scales 



Urajiro-kamba. Tree with grayish or whitish bark, the longer than the lateral ones. Reported to occur in Hok- 



branchlets glabrous or nearly so, dark purple-brown to dark kaido. 



red-brown; leaves elliptic, obovate or ovate, 4-8 cm. long, 5. Betula schmidtii Regel. Ono-ore-kamba. Tree 

 2.5-5 cm. wide, rather thin, acute, coarsely doubly toothed, the with dark gray bark peeling off into small thick pieces, the 

 base obtuse to rounded, vivid green and glabrous above, branchlets dark-brown, resinous-glandular and pilose while 

 glaucous and slighdy appressed-pilose on nerves beneath, the young; leaves narrowly ovate-ellipdc to ovate, acuminate, with 

 lateral nerves of 8 to 14 pairs, the petioles 7-15 mm. long, irregular suberect small teeth, rounded to broadly cuneate at 

 white-silky while young; fruidng aments erect, short-peduncu- base, 4-8 cm. long, rather dull, appressed-pilose on nerves be- 

 late, 3-4 cm. long, oblong-cylindric, the fruiting scales thinly neath, the lateral nerves of 9 to 10 pairs, the petioles 5-10 mm. 

 long-pilose, 12-15 mm. long, 3-lobed, the lateral lobes ascend- long, pilose; fruiting aments short-pedunculate, oblong-ey- 

 ing, about half as long as the midlobe; nuts ovoid-orbicular, lindric, 2-3 cm. long, 8-9 mm. in diameter, erect, the scales 



about 3 mm. long, narrowly winged on both sides. Moun- 5-6 mm. long, shghtly resinous, short-ciliolate, the midlobe 



tains; Honshu (Kinki Distr. and easrw.). linear-lanceolate, the lateral ones obliquely ascending, about 



3. Betula platyphylla Sukatschev var. japonica (Miq.) half as long as the midlobe, subacute; nuts ovoid, about 2 mm. 



Hara. B. japonica Sieb., non Thunb.; B. alba var. japonica long, with very narrow wings. Honshu (centr. and n. 



Miq.; B. alba var. tauschii Regel, pro parte; B. tauschii (Regel) distr.). Korea, Manchuria, and Ussuri. 



Koidz. Shira-kaba, Shira-kamba. Tree with white bark, 6. Betula chichibuensis Hara. Chichibu-minebari. 



the branchlets dark purple-brown, with resinous glands while Tree; branchlets densely villous while young, scarcely glandu- 

 young; leaves broadly deltoid-ovate, 5-7 cm. long, 4-6 cm. lar; leaves ovate or oblong-ovate, 3-6 cm. long, 1.5-3.2 cm. 

 wide, truncate at base, acuminate, doubly toothed, glabrous or wide, short-acuminate, minutely and unequally duplicate- 

 sparsely short-pilose beneath, usually with tufts of axillary serrate, rounded to broadly cuneate at base, densely white- 

 hairs, rather dull above, the lateral nerves weak, of 6 to 8 villous at least on the nerves beneath, lateral nerves of 14 to 

 pairs, the petioles 1-3 cm. long, rather slender; fruiting 18 pairs, the petioles 4-7 mm. long, white-villous; pistillate 

 aments short-cylindric, pendulous, pedunculate, 3-4.5 cm. aments cylindric, short-peduncled, erect, 1.5-2.5 cm. long, 7-10 

 long, 8-10 mm. in diameter, the scales 3.5-4.5 mm. long, mm. wide, the scales 3.5-5 mm. long, deeply 3-lobed, pubes- 

 puberulous outside, the lateral lobes spreading, obovate, 2-3 cent and eglandular on back, the lateral lobes slighdy shorter 

 times as long as the midlobe; nuts narrowly obovate to ovate, than the median; nuts ovate, 2-3 mm. long, scarcely winged. 



1.5-2.2 mm. long, puberulous, the wing 1.5-2 times wider Honshu (Chichibu). 



than the nuts. Highlands; Hokkaido, Honshu (centr. and 7. Betula ermanii Cham. B. incisa Koidz.; B. shi}(p]{i- 



n. distr.) ; locally abundant. ana Nakai Dake-kamba, Take-kamba. Tree or large 



Var. kamtschatica (Regel) Hara. B. alba var. \am- shrub with gray-brown to gray-white bark peeling off into 



tschatica Regel Ezo-no-shira-kamba. Leaves often broadly thin pieces, the branchlets resinous when young, soon becom- 



cuneate at base. Occurs with var. japonica. The typical ing brownish purple; leaves deltoid-ovate to broadly so, 5-10 



phase occurs in the cooler areas of e. Asia. cm. long, 4-7 cm. wide, acuminate, irregularly mucronate- 



Betula X avaczensis Komar. Oku-Ezo-shira-kamba, is a toothed, rounded to shallowly cordate, thinly pilose on nerves 



