白桦 Betula pendula subsp. mandshurica

  • Scientific Name: Betula pendula subsp. mandshurica (Regel) Ashburner & McAll.
  • Ref: Gen. Betula: 291. 2013
  • Synonyms:
    • Betula ajanensis Kom.
    • B. alaskana Sarg.
    • B. alba var. resinifera Regel
    • B. alba subsp. mandshurica Regel
    • B. alba var. tauschii Regel
    • B. austrosichotensis V.N.Vassil. & V.I.Baranov
    • B. cajanderi Sukaczev
    • B. demetrii I.V.Vassil.
    • B. grandifolia Litv.
    • B. japonica var. resinifera (Regel) H.J.P.Winkl.
    • B. kamtschatica (Regel) C.-A.Jansson
    • B. latifolia var. cuneifolia Nakai
    • B. mandshurica (Regel) Nakai
    • B. neoalaskana Sarg.
    • B. papyrifera subsp. humilis (Regel) A.E.Murray
    • B. pendula var. japonica (Miq.) Rehder
    • B. pendula subsp. kamtschatica (Regel) Shemberg
    • B. platyphylla Sukaczev
    • B. resinifera Britton
    • B. tauschii (Regel) Koidz.
    • B. verrucosa var. japonica (Miq.) A.Henry
  • English Common Name: Manchurian white birch, Japanese white birch, Siberian silver birch
  • Chinese Common Name: 白桦 báihuà
  • Japanese Common Name: シラカバ [白樺] shirakaba
  • Family: Betulaceae
  • Genus: Betula
  • Distribution: Temperate broad-leaved forests, shaded, S-facing slopes, ridges, dry, sunny slopes, marshes, forming vast, pure stands or mixed with Acer, Larix, Picea, Tilia, and other species of Betula; 700-4200 m. Gansu, Hebei, Heilongjiang, Henan, Jiangsu, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, SW and W Sichuan, SE Xizang, NW Yunnan [Japan, N Korea, E Mongolia, Russia (Far East, Siberia)]
  • Photo: 07/14/2008, Mt. Changbai, Jilin
  • Note: most common synonym: Betula platyphylla Sukaczev, Trav. Mus. Bot. Acad. Imp. Sci. St.-Petersbourg. 8:220. 1911.
Trees to 30 m tall; bark grayish white, exfoliating in sheets. Branches not pendulous, dark gray or dark brown, glabrous; branchlets brown, sparsely resinous glandular. Petiole slender, 1-2.5 cm; leaf blade triangular, ovate-triangular, rhombic-triangular, rhombic-ovate, or broadly ovate, 3-9 × 2-7.5 cm, abaxially densely resinous punctate, glabrous, bearded in axils of lateral veins, adaxially sparsely pubescent and resinous glandular when young, base truncate, broadly cuneate, or cuneate and subcordate, margin doubly or simply serrate, or incised-serrate, apex acute, acuminate, or caudate-acuminate; lateral veins 5-7(-9) on each side of midvein. Female inflorescence pendulous, oblong or oblong-cylindric, 2-5 × 0.6-1.4 cm; peduncle slender, 1-2.5 cm; bracts 5-7 mm, densely pubescent and ciliate, 3-lobed, middle lobe triangular-ovate, lateral lobes erect or spreading to recurved, ovate or suborbicular, slightly shorter to longer than middle lobe. Nutlet narrowly oblong, oblong, or ovate, 1.5-2 × 1-1.5 mm, sparsely pubescent, with membranous wings slightly longer than and about as wide as nutlet. Fl. Jun-Jul, fr. Jul-Sep. 2n = 28. (Flora of China)

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