BETULA 



BETULA 



499 



urticifdlia, Spach (B. urticifolia, Regel. B.dlbaasplenii- 

 J'olia, Hort.). Lvs. small, deep green, irregularly 

 incised. Var. variegata, Zabel (B. alba fbliis variegatis, 

 Hort.). An inconstant form with variegated Ivs. There 

 are also a number of geographical varieties as var. 

 carpatica, Koch; var. songarica, Regel; var. tortudsa, 

 Koehne; var. Murithii, Gremi, which are rarely met 

 with in cult, and horticulturally are of no importance. 

 In the wild state this species is generally found 

 in moist places, often in swamps, while the preceding 

 species prefers drier situations. 



11. papyrifera, Marsh. (B. papyrdcea, Ait. B. grdn- 

 dis, Schrad.). PAPER or CANOE BIRCH. Figs. 550, 551. 

 Tree, 60-80, exceptionally 120, ft.: branchlets slightly 

 glandular, hairy when young: Ivs. ovate, narrowed to 

 cordate at the base, acuminate, coarsely and usually 

 doubly serrate, pubescent on the veins beneath or 

 nearly glabrous, \ 1 A-^ 1 A in. long: strobiles peduncled, 

 1-2 in. long; scales with short and broad divergent 

 lateral lobes. Northern states from the Atlantic to 

 Pacific coast. S.S. 9:451. Em. 238. G.F. 8:223. H.T. 

 120,121. I.T. 4:125. Ornamental tree, with very 

 white trunk and a loose, graceful head when older. 

 Bark known for its use in making Indian canoes. Var. 

 cordifdlia, Regel (B. pyrifblia and B. platyphylla, Hort.). 

 Lvs. broadly ovate, usually cordate. S.S. 14:724. Var. 

 minor, Tuckm. Low, bushy tree with smaller Ivs. and 

 frs. Mts. of New England and X. Y. 



cc. Bark orange-broum: branchlets glandular and hairy 

 when young: lateral lobes of scales upright, shorter 

 than the middle lobe. 



12. occidentalis, Hook. (B. Lyalliana, Koehne. B. 

 Tea var. occidentalis, Dipp.). Tree, to 100 ft.: 



branches in older trees often pendulous: Ivs. ovate, 3-4 

 in. long, usually rounded at the base, acute, coarsely 

 and mostly doubly serrate, resinous while young and 

 villous on the veins, glabrous at maturity except on 

 the puberulous veins: strobiles cylindric, Iji-IJi 

 in. long; scales ciliate, with rhombic-ovate upright 

 lateral lobes, about half as long as the oblong middle 



lobe. B. C. to Wash. 



S.S. 14:725. 



BB. Wingsnarrower than 

 the nut: shrubs, 115 

 ft.: Ivs. small, short- 

 pelioled: cones erect, 

 c. Branchlets glandular, 



not pubescent. 

 13. glandulosa, 

 Michx. Only 1-tft.: 

 Ivs. short - petioled, 

 rounded or cuneate 

 at the base, 

 orbicular or 

 broadly ob- 

 jovate, ob- 

 ' tuse, dentate, 

 glabrous, J^- 

 1J-3 in. long: 

 strobiles pe- 

 duncled, J^- 

 3 4 m. long; 

 lobes of scales 

 nearly equal, 



550. Staminate catkin (natural size) and flowers s ' ' 8 " M v 

 (enlarged) of Betula papyrifera. spreading; 



wings of nut- 

 let sometimes as broad as its body. Newfoundland to 

 Alaska, south to Mich., and in the Rocky Mts. to 

 Colo. B.B. 1:510. 



cc. Branchlets pubescent or nearly glabrous, not glandular. 



14. pumila, Linn. Usually 2-8, rarely 15, ft.: branch- 

 lets tomentose or pubescent, at least when young: Ivs. 



orbicular or oval, acute or obtuse, coarsely dentate, pale 

 and glabrous or pubescent beneath, J^-2 in. long: 

 strobiles peduncled, 1^1 in. long; lateral lobes of the 

 pubescent scales spreading, shorter than the middle 

 one; wings of nutlet half as broad as its body or 

 narrower. Newfoundland to Minn., south to Ohio. 

 B.B. 1:511. W.B. 71. Var. fasti- 

 giata, Rehd. (B. humilis fasti- 

 giata, Hort.). Shrub, with upright 

 branches, forming a narrow pyra- 

 mid: branchlets soft pubescent: Ivs. 

 broadly rhombic to suborbicular, 

 1-1 % in- long, broadly cuneate at 

 base, pubescent beneath only on the 

 veins, resin-dotted on both sides. 



15. nana, Linn. Low, spreading, 

 rarely 4 ft. : Ivs. orbicular or cuneate- 

 obovate, crenate, rounded at apex, 

 glabrous, ^-^in. long: strobiles 551 Catkin of " Betula 

 nearly sessile, ]^-Y ? m. long; the papyrifera. (XH) 

 upper scales usually entire, the 

 lower ones 3-lobed; wings of nutlets very narrow. 

 Arctic N. E. Amer., N. Eu., Siberia. B.B. 1:511. 

 W.B. 71. A low, graceful shrub for rockeries and 

 rocky slopes. 



B. acuminata, Wall.=B. alnoides. B. alaskdna, Sarg. Allied to 

 B. occidentalis. Tree, to 40, rarely 80, ft.: bark grayish white: 

 branchlets densely glandular: Ivs. rhombic-ovate, lJ^-3 in. long, 

 truncate to broadly cuneate, pubescent on the veins beneath or 

 finally glabrous; petiole about 1 in. long: scales of strobiles ciliate. 

 Alaska. S.S. 14:726. B. alleghaniensis, Brit. Intermediate be- 

 tween B. lenta and B. lutca. Bark either close and furrowed or peel- 

 ing off in thin flakes: young branchlets pubescent: Ivs. usually 

 cordate at base and pubescent beneath : strobiles ovoid-oblong, about 

 1 in. long; scales jiin. long, 3-lobed about to the middle. Que. 

 and Mich, to Ga. B. alnoides, Hamil. (B. acuminata, Wall. B. 

 cylindrostachya, Wall.). Allied to B. Maximowiczii. Tree, to 60 ft. : 

 young branchlets pubescent ; bark brown: Ivs. ovate-oblong to ovate- 

 lanceolate, 2)^-6 in. long, rounded at the base, doubly cuspidate- 

 serrate, with 10-13 pairs of veins: strobiles in racemes. Himalayas, 

 S.W. China. W.B. 90. B. alpestris, Fries=B. intermedia. B. 

 Borffffrevei, Zabel (B. papyrifera X B. pumila). Shrubby. Inter- 

 mediate between the parents, but more similar to B. pumila. Raised 

 at Hann., Muenden, Germany, from American seed. B. cserulea, 

 Blanch. Allied to B. pendula. Tree, to 60 ft.: young branchlets 

 hairy: Ivs. ovate, 2-3 H in. long, rounded or cuneate at base, acu- 

 minate, sharply serrate," dull bluish green above, slightly hairy 

 along the veins beneath: scales of strobiles similar to those of B. 

 populifolia. Vt., Me. S.M. 201. B. carpinif&lia, Sieb. & Zucc.= 

 B. grossa. B. carpiniffilia, Ehrh.=B. lenta. B. corylifiilia, Regel. 

 Allied to B. nigra. Lvs. broadly elliptic or obovate, 1 %-2 % in. long, 

 coarsely dentate, silky on the veins beneath, with 10-14 impressed 

 pairs of veins: strobiles cylindric. Japan. S.I.F. 2:14. W.B. 60. 

 The plant cult, under this name is usually B. Ermanii. B. cylindro- 

 stachya, Wall.=B. alnoides. B. dahfirica. Pall. Allied to B. pubes- 

 cens. Tree, to 60 ft.: bark brown: branchlets glandular, hairy when 

 young: Ivs. ovate, 1-2 in. long, pubescent on the veins beneath: 

 strobiles oblong; wings of nutlet half as broad as body or less. 

 Dahuria, Manchuria. Pallas, Fl. Ross. 39. B. excelsa. Ait. (B. alba 

 var. excelsa, Regel). Allied to B. pubescens. Large tree: bark yel- 

 lowish brown: young branchlets densely pubescent: Ivs. broadly 

 ovate to obovate, 1-2 J^ in. long, rounded or subcordate at the base, 

 acute, pubescent beneath: strobiles cylindric-oblong, upright or 

 nodding; lateral lobes of scales slightly shorter than the middle one 

 Of unknown origin. W.D.B. 2 : 95. N.D. 3 : 52. B. Jontinalis, Sarg. 

 (B. occidentalis, Nutt., not Hook. B. rhombifolia, Nutt., not 

 Tausch). Allied to B. occidentalis. Small tree, to 40 ft. or shrubby: 

 bark dark bronze color, lustrous: branchlets glandular: Ivs. broadly 

 ovate, 1-2 in. long, truncate to broadly cuneate, sharply, often 

 doubly serrate: strobiles cylindric-oblong, 1-1 ^ in. long; scales gla- 

 brous or puberulous. B. C. to Calif., east to Dak. and Colo. S.S. 

 9:453 (as B. occidentalis). B. frulicdsa. Pall. (B. Gmelinii. Bunge). 

 Allied to B. glandulosa. Shrub, to 15 ft.: branchlets glandular and 



E 



h 



pubescent: Ivs. ovate-elliptic, H~l % in. long, glabrous at length 

 and usually glandular beneath: strobiles oblong-cylindric, 5i-l in. 

 long, wings about as broad as nutlet. Siberia, Manchuria. Pallas, 

 Fl. Ross. 40. B. fflobisjnca, Shirai. Allied to B. ulmifolia. Tree, to 

 60 ft.: bark grayish brown: Ivs. broadly rhombic-ovate, 1 H-2^ in. 

 long, short-acuminate, unequally serrate, with about 10 pairs of 

 veins, pubescent on the veins beneath : strobiles subglobose or ovoid, 

 about 1 ^ in. long; scales deeply 3-lobed with spatulate lobes. 

 Japan. S.I.F. 1:21. W.B. 68. B. Gmflinii, Bunge=B. fruticosa. 

 B. grdssa, Sieb. & Zucc. (B. carpinifolia, Sieb. & Zucc.). Tree: 

 branchlets glabrous: Ivs. ovate, 2-4 in. long, unequally serrate, with 

 10-15 pairs of veins, pubescent on the veins beneath and glandular- 

 punctate: strobiles nearly sessile, elliptic-ovoid; middle lobe of the 

 scale slightly longer than the lateral ones. Japan. S.I.F. 1:22. B. 

 humilia, Schrank. Allied to B. glandulosa. Shrub, 2-6 ft.: branch- 

 lets glandular and slightly pubescent at first: Ivs. ovate or subor- 

 bicular, H-l \i in. long, crcnately serrate, glabrous: strobiles ovoid, 

 about Hin. long. N. and W. Eu.. N. Aria, G.W.H. 2:149. H.W.2: 



