BETULA 



BETULA 



499 



urticifdlia, Spach {B. urticifdlia, Regel. B. dlba asplenii- 

 jblia, Hort.). Lvs. small, deep green, irregularly 

 incised. Var. variegata, Zabel (B. dlba foliis variegalis, 

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

 are also a number of geographical varieties as var. 

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

 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. pap3rrifera, jMarsh. (B. papyr&cea, Ait. B.grdn- 

 dis, Schrad.). Paper or Canoe Birch. Figs. 5.50, 5.51. 

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

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

 cordate at the base, acuminate, coarsely and usually 

 doubl}' serrate, pubescent on the veins beneath or 

 nearly glabrous, lli-^l'i 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. 

 cordifSlia, Regel (B. pyrifdlin and B. platyphylla, Hort.). 

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

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

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



cc. Bark orange-brown: branchlets glandular and hairy 

 when young: lateral lobes of scales upright, shorter 

 than the middle lobe. 



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

 ■papyracea var. occidentalis, Dipp.). Tree, to 100 ft.: 

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

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

 and mostly doubly serrate, resinous while young and 

 vill(5us on the veins, glabrous at maturity except on 

 the puberulous veins: strobiles cylindric, lli-lli 

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

 lateral lobes, about half as long as the oblong middle 



lobe. B. C. to Wash. 

 (liSSa& S.S. 14:725. 



im.Wings narrower than 

 the nut: shrubs, 1-16 

 ft.: lvs. small, short- 

 petioled: cones erect. 

 c. Branchlets glandular, 

 not pubescent. 

 13. glanduldsa, 

 Michx. Only 1^ ft.: 

 lvs. short - petioled, 

 rounded or cuneate 

 at the base, 

 orbicular or 

 broadly ob- 

 ovate, ob- 

 tuse, dentate, 

 glabrous, J^- 

 1}^ in. long: 

 strobiles pe- 

 duncled, li- 

 Sjin. long; 

 lobes of scales 

 nearly equal, 

 slightly 

 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. p&mila, Linn. Usually 2-8, rarely 15, ft.: branch- 

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



553. Staminate catkin (natural size) and flowers 

 (t-iilargcd) of Betula papyrifera. 



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

 and glabrous or pubescent beneath, }'2-2 in. long: 

 strobiles peduncled, J^-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. VV.B. 71. Var. fasti- 

 giata, Rehd. (B. hiimilis fasti- 

 giata, Hort.). Shrub, with upright 

 branches, forming a narrow pyra- 

 mid: branchlets soft pubescent: lvs. 

 broadly rhombic to suborbicular, 

 1-1 J 2 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. : lvs. orbicular or cuneate- 

 obovate, crenate, rounded at apex, 

 glabrous, J<C-?.iin. long: strobiles 551. catkin of Betula 

 nearly sessile, M-W"^. long; the papyrifera. (x'2) 

 upper scales usually entire, the 

 lower ones 3-lobed; wings of nutlets verv 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. ainoides. — B. alaskdna. Sarg. Allied to 

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

 branchlets densely glandular: lvs. rhombic-ovate, 1J2-3 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. alkghani crisis, Brit. Intermediate be- 

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

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

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

 1 in. long: scales ?4in. long. 3-lobed about to the middle. Que. 

 and Mich, to Ga. — B. ainoides, Hamil. (B. acuminata, Wall. B. 

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

 young branchlets pubescent: bark brown: lvs. ovate-oblong to ovate- 

 lanceolate, 2 ' 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. alpcstris. Fries=B. intermedia. — B. 

 Borggrcvei, 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, cseriilea, 

 Blanch, .\llied to B. pendula. Tree, to 60 ft.; young branchlets 

 hairy; lvs. ovate, 2-3 32 in. long, rounded or cuneate at ba.se. 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. carpinifdlia, Sieb. & Zucc.= 

 B. grossa. — B. carpinifolia, Ehrh.^B. lenta. — B. corylifdlia, Regel. 

 Allied to B. nigra. Lvs. broadly elliptic or obovate, 1 ^4-2 V2 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- 

 slachya. Wall. ^B. ainoides. — B. dahiirica. Pall. Allied to B. pubes- 

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

 young; lvs. 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. iB. alba 

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

 lowish brown: young branchlets densely pubescent: lvs. broadly 

 ovate to obovate, 1-2 J3 in. long, rovmded or pubcordate at the base, 

 acute, pubescent beneatli: 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.U. 3:.52. — B. /onlirtalis, Surg. 

 (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; lvs. broadly 

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

 doubly serrate; strobiles cylindric-oblong. 1-lH >"■ long; scales gla^ 

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

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

 .■Mlicd to B. glandulo-sa. Shrub, to 15 ft.: branchlets glandular and 

 pubescent: Iv.s. ovate-elliptic, M-l'A in. long, glabrous at length 

 and u.sually glandular beneath: strobiles oblong-cylindric. ?i-l in. 

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

 Fl. Ross. 40. — B. glohispica, Shirai. .Mlied to B. ulmifolia. Tree, to 

 GO ft.; bark grayish brown: lvs. broadly rhombic-ovate, 1 ^2-2 J-j in. 

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

 veins, pubescent on the veins beneath: strobiles subglobo.se or ovoid, 

 aijout 1 ' 2 in. long; scales deeply .S-lobed with spatulate lobes. 

 Japan. S.I.F. 1:21. W.B. 68.— B. Gm/(inii, Bunge=B. fruticosa. 

 — B. gr6ssa, Sieb. & Zucc. (B. carpinifolia. Sieb. & Zucr. ). Tree: 

 branchlets glabrous: lvs. 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. 

 ftumifi.s. Schrank. Allied to B. glandulosa. Shrub. 2-6 ft.; branch- 

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

 bicular, '2-I '4 in. long, crenately serrate, glabrous: strobiles ovoid, 

 about Jzin. long. N. and W. Eu., N. Asia. G.W.H.2:149. H.W.2: 



