|Betula subsp. var.||Birch|
Birch is the name of any tree of the genus Betula, in the family Betulaceae, closely related to the beech/oak family, Fagaceae. These are generally small to medium-size trees or shrubs, mostly of northern temperate climates. The simple leaves may be toothed or lobed. The fruit is a small samara, although the wings may be obscure in some species. They differ from the alders (Alnus, the other genus in the family) in that the female catkins are not woody and disintegrate at maturity, falling apart to release the seeds, unlike the woody cone-like female alder catkins.
Pests and diseases
See also: Betula classification birch
- Birches of North America include
- Betula alleghaniensis - Yellow Birch (B. lutea)
- Betula cordifolia - Mountain Paper Birch
- Betula glandulosa - American Dwarf Birch
- Betula lenta - Sweet Birch, Cherry Birch, or Black Birch
- Betula michauxii - Newfoundland Dwarf Birch
- Betula nana - Dwarf Birch or Bog Birch (also in northern Europe and Asia)
- Betula neoalaskana - Alaska Birch or Yukon Birch
- Betula nigra - River Birch or Black Birch
- Betula occidentalis - Water Birch or Red Birch (B. fontinalis)
- Betula papyrifera - Paper Birch, Canoe Birch or American White Birch
- Betula populifolia - Gray Birch
- Betula pumila - Swamp Birch
- Betula albosinensis - Chinese Red Birch
- Betula albosinensis var. septentrionalis - North Chinese Red Birch
- Betula alnoides - Alder-leaf Birch
- Betula austrosinensis - South China Birch
- Betula chinensis - Chinese Dwarf Birch
- Betula ermanii - Erman's Birch
- Betula grossa - Japanese Cherry Birch
- Betula jacquemontii (Betula utilis subsp. jacquemontii) - White-barked Himalayan Birch
- Betula mandschurica - Manchurian Birch
- Betula mandschurica var. japonica - Japanese Birch
- Betula maximowiczii - Monarch Birch
- Betula medwediewii - Caucasian Birch
- Betula nana - Dwarf Birch (also in northern North America)
- Betula pendula - Silver Birch
- Betula platyphylla (Betula pendula var. platyphylla) - Siberian Silver Birch
- Betula pubescens - Downy Birch, White Birch or European White Birch (also in northern Asia)
- Betula pubescens subsp. tortuosa - Arctic White Birch (subarctic Eurasia, Greenland)
- Betula szechuanica (Betula pendula var. szechuanica) - Sichuan Birch
- Betula utilis - Himalayan Birch
- Note: many American texts have B. pendula and B. pubescens confused, though they are distinct species with different chromosome numbers
Standard Cyclopedia of Horticulture
|Standard Cyclopedia of Horticulture|
Betula (ancient Latin name). Betulaceae. Birch. Ornamental deciduous woody plants grown chiefly for their bright green handsome foliage.
Trees or shrubs: winter-buds usually conspicuous, sessile, with several imbricate scales: Lvs. alternate, petioled, serrate or crenate: fls. monoecious, apetalous, in catkins, staminate formed in autumn and remaining naked during the winter, every scale bearing 3 fls., each with a minute 4-toothed calyx and with 2 stamens divided at the apex; pistillate catkins oblong or cylindrical, bearing 3 naked ovaries in the axil of every scale consisting of 3 connate bracts: fr. a minute nut, often erroneously called seed, with membranous wines, dropping at maturity with the 3-pointed scales from the slender rachis of the strobile.—About 35 species in N. Amer., Eu., N. and Cent. Asia, especially in the northern regions. No tree goes farther north than the birch, in N. Amer. B. papyrifera reaches 66° north latitude, and in Eu. B. pubescens goes to the N. Cape, and is still a forest tree at 70°.
The birches are often conspicuous on account of their colored bark, and slender usually pendulous staminate catkins before the leaves and much smaller pistillate catkins, followed by subglobose to cylindric strobiles. The hard and tough wood is often used in the manufacture of furniture and of many small articles, in making charcoal, and for fuel; from the bark, boxes, baskets, and many small articles are made; also canoes from that of the B. papyrifera; in Russia and Siberia it is used in tanning leather. The sap of some species is used as a beverage. The birches are very ornamental park trees, hardy, except two or three Himalayan species, and especially valuable for colder climates. They are essentially northern trees and are short-lived in warmer regions, particularly mountain species like B. lutea, while B. nigra and B. lenta are better suited for a warmer climate than most other species. Their foliage is rarely attacked by insects, and turns to a bright or orange-yellow in fall. Their graceful habit, the slender, often pendulous branches, and the picturesque trunks make them conspicuous features of the landscape. Especially remarkable are those with white bark, as B. papyrifera, B. populifolia, B. pendula, B. Ermanii, and also B. Maximowiczii with yellow bark.
Most birches prefer moist, sandy and loamy soil; but some, as B. pendula and B. populifolia, grow as satisfactorily in dry localities and poor soil as in swamps and bogs, and they are especially valuable in replanting deserted grounds as nurses for other trees; both are comparatively short-lived trees.
Propagation is readily accomplished by seeds, gathered at maturity and sown in fall, or usually kept dry during the winter, or stratified; but B. nigra, which ripens its fruits in June, must be sown at once, and by fall the seedlings will be several inches high. The seeds should be sown in sandy soil, rather thick, as the percentage of perfect seeds is not very large, slightly or not at all covered, but pressed firmly into the ground and kept moist and shady. The seedlings must be transplanted when one year old. Rarer species and varieties are grafted, usually on B. lenta, B. papyrifera, B. nigra or B. pendula. Cleft or tongue-grafting in early spring, on potted stock in the greenhouse, is the best method. Budding in summer is also sometimes practised. Shrubby forms may also be increased by layers, and B. nana by greenwood cuttings under glass.
B. acuminata, Wall.-B. alnoides.—B. alaskana, Sarg. Allied to B. occidentalis. Tree, to 40. rarely 80, ft.: bark grayish white: branchlets densely glandular: Lvs. rhombic-ovate, 1½-3 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 between B. lenta and B. lutea. Bark cither close and furrowed or peeling off in thin flakes: young branchlets pubescent: Lvs. usually cordate at base and pubescent beneath: strobiles ovoid-oblong, about 1 in. long; scales ¼ in. 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: Lvs. ovate-oblong to ovate- lanceolate, 2½-6 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. Borggrevei, Zabel (B. papyrifera X B. pumila). Shrubby. Intermediate between the parents, but more similar to B. pumila. Raised at Hann.. Muenden, Germany, from American seed.—B. caerulea, Blanch. Allied to B. pendula. Tree, to 00 ft.: young branchlets hairy: lvs. ovate, 2-3½ in. long, rounded or cuneate at base, acuminate, 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. carpinifolia, Sieb. & Zucc.- B. grossa.—B. carpinifolia, Ehrh.-B. lenta.—B. corylifolia. Regel. Allied to B. nigra. Lvs. broadly elliptic or obovate, 1¾-2½ 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. cylindrostachya, Wall.-B. alnoides.—B. dahurica, Pall. Allied to B. pubescens. 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. (B. alba var. excelsa. Regel). Allied to B. pubescens. Large tree: bark yellowish brown: young branchlets densely pubescent: Lvs. broadly ovate to obovate, 1-2⅓ in. long, rounded or subcordate at the base, acute, pubescent beneath: strobile 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. fontinalis, Sarg. (B occidentalis, Nutt., not Hook. B. rhombifolia. Null., 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. 1-1¼ in. long; scales glabrous or puberulous. B. C. to Calif., cast to Dak. and Colo. 8.S. 9:453 (as B. occidentalis).—B. fruticosa, Pall. (B. Gmelinii, Bunge). Allied to B. glandulosa. Shrub, to 15 ft.: branchlets glandular and pubescent: Lvs. ovate-elliptic, ½-1½ in. long, glabrous at length and usually glandular beneath: strobiles oblong-cylindric, ¾-1 in. long, wings about as broad as nutlet. Siberia, Manchuria. Pallas, Fl. Ross. 40.—B. globispica. Shirai. Allied to B. ulmifolia. Tree, to 60 ft.: bark grayish brown: Lvs. broadly rhombic-ovate, 1½-2½ in. long, short-acuminate, unequally serrate, with about 10 pairs of veins, pubescent on the veins beneath: strobiles subglobose or ovoid, about 1½ in. long; scales deeply 3-lobed with spatulate lobes. Japan. S.I.F. 1:21. W.B. 68.—B. Gmelinii. Bunge-B. fruticosa. —B. grossa, Sieb. & Zucc. (B. carpinifolia. Sieb. & Zucc.). 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. humilis, Schrank. Allied to B. glandulosa. Shrub, 2-6 ft.: branchlets glandular and slightly pubescent at first: Lvs. ovate or suborbicular. ½-1¼ in. long, crenately serrate, glabrous: strobiles ovoid, about ½in. long. N. and W. Eu., N. Asia. G.W.H. 2:149. H.W. 2: p.26. R.F.G. 12:1279.—B. intermidia. Thomas (B. alpentris. Fries. B. pubescens x B. nana). Shrub: Lvs. orbicular or ovate, ⅓-1 in. long, crenate-serrate, usually pubescent while young, and often glutinous, finely glabrous: strobiles oblong: lateral lobes of scale upright and usually shorter than the middle one. N. Eu.—Natural hybrid; very variable.—B. Jackii, Schneid. (B. lenta xpumila). Shrub: bark of the odor of B. lenta: Lvs. usually obovate, 1-2 in. long, usually with about 7 pairs of veins: strobiles oblong, ½-¾ in. long; lateral lobes of scales spreading, somewhat shorter than the middle one. Originated at the Arnold Arboretum. G.F. 8:245.— B. kenaica, Evans. Allied to B. occidentalis. Tree, to 40 ft. : bark grayish white or light reddish brown: branchlets glabrous, not or slightly glandular: Lvs. ovate, 1½-2 in. long, cuneate or rounded at the base, irregularly, often doubly serrate, glabrous: strobiles cylindric-oblong, about 1 in. long, glabrous. Alaska. S.S. 14:723.—B. Koehnei, Schneid. (B. papyrifera X pendula). Intermediate between the parents. Tree: branchlets sparingly pubescent: Lvs. ovate, 2-3½ in. long, usually truncate at base, acuminate; rather finely and doubly serrate: scales of strobiles similar to those of B. papyrifera. Origin unknown.—B. luminifera, Winkl. Allied to B. alnoides. Lvs. ovate, subcordate at the base, serrate with acuminate teeth, 3-5 in. long: strobiles solitary, 2-3 in. long. Cent. China, W. 92.—B. Mid-wedjewii, Regel. Allied to B. utilis. Tree: young branchlets hairy: Lvs. broadly ovate to obovate, 2-3 in. long, rounded or sometimes subcordate at the base, short-acuminate, glabrous or pubescent on the veins beneath: strobiles cylindric-oblong, 1-1¾ in. long; wings of nutlet often 4 times narrower than its body. Caucasus. Gt. 36, p. 384.—B. occidentalis, Nutt.. not Hook.-B. fontinalis.—B. Purpusii, Schneid. (B. lutea xpumila). Shrubby or small tree: Lvs. oblong-ovate, 1-2 in. long, with 7-9 pairs of veins, soft-pubescent beneath. Intro, to Eu. from Mich.—B. Raddeana, Trautv. Tree: Lvs. ovate-pubescent on the veins beneath, with 6-7 pairs of veins, 1-2 in. long: strobiles oblong, upright, ¾ in. long; wings as broad as nutlet. Caucasus.—B. rhombifolia, Nutt.-B. fontinalia.
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963