Betula delavayi
Sponsor
Kindly sponsored by the Banks family in memory of Lawrence Banks CBE DL VMH
Credits
Hugh A. McAllister, Kenneth Ashburner, Paul Bartlett & Martin Deasy (2026)
Recommended citation
McAllister, H. A., Ashburner, K., Bartlett, P. & Deasy M. (2026), 'Betula delavayi' from the website Trees and Shrubs Online (treesandshrubsonline.
Synonyms
- Betula chinensis var. delavayi (Franch.) C.K.Schneid.
- Betula forrestii (W.W.Sm.) Hand.-Mazz.
- Betula delavayi var. forrestii W.W.Sm.
- Betula delavayi var. polyneura L.C.Hu
- Betula delavayi var. microstachya P.C.Li
Other taxa in genus
- Betula alleghaniensis
- Betula alnoides
- Betula ashburneri
- Betula bomiensis
- Betula × caerulea
- Betula calcicola
- Betula celtiberica
- Betula chichibuensis
- Betula chinensis
- Betula cordifolia
- Betula corylifolia
- Betula costata
- Betula cylindrostachya
- Betula davurica
- Betula ermanii
- Betula fargesii
- Betula fruticosa
- Betula glandulosa
- Betula globispica
- Betula gmelinii
- Betula grossa
- Betula gynoterminalis
- Betula humilis
- Betula kweichowensis
- Betula lenta
- Betula luminifera
- Betula lutea
- Betula maximowicziana
- Betula medwediewii
- Betula megrelica
- Betula michauxii
- Betula microphylla
- Betula middendorffii
- Betula murrayana
- Betula nana
- Betula nigra
- Betula occidentalis
- Betula ovalifolia
- Betula papyrifera
- Betula pendula
- Betula populifolia
- Betula potaninii
- Betula pubescens
- Betula pumila
- Betula raddeana
- Betula schmidtii
- Betula skvortsovii
- Betula tianschanica
- Betula utilis
- Betula utilis subsp. albosinensis
- Betula utilis subsp. jacquemontii
- Betula utilis subsp. occidentalis
- Betula utilis subsp. utilis
Editorial Note
This TSO article is an edited digest of the species account in Kenneth Ashburner and Hugh McAllister, The Genus Betula: A Taxonomic Revision of Birches (2013; repr. 2016).
Trees and Shrubs Online, 23 June 2026
Shrub or small tree 4–12 m. Young shoots densely silky-hairy with reddish glands; stipules hardly persistent. Twigs brown; second-year twig still pale brown with white lenticels. Buds narrowly ovoid, to 7 × 3 mm. Leaves with petiole to 8 mm, very dark green and moderately shiny above, yellow-green and dull or sometimes quite shiny below, elliptic-ovate, to 70(–90) × 40(–46) mm; length usually about twice the width but sometimes broader, rounded at base and acute at apex, convex and somewhat revolute at the margins, leathery with 8–12(–16) pairs of veins inserted about 5–6 mm apart, usually somewhat indented above; entering base of tooth but not running to sinus, (1–)2–3(–5) teeth between main secondary vein ends; weak basal veins usually present; sparsely hairy above, persistently silky-hairy along the midrib and veins below; reddish glands on lower surface when young; blade:petiole ratio c. 1:9. Male catkins to 3 terminal with up to 2 lateral, to 30 mm; scales peltate, overlapping towards the apex. Fruiting catkins to 32 × 15 mm, elliptic-oblong; peduncle < 5 mm; scales about 8.5 × 6 mm, margin ciliate, adaxial surface puberulent, abaxial glabrous; terminal lobe c. 4.5 mm, rhombic-oblong; lateral lobes c. 3 mm, oblong. Seed c. 3 × 2.5 mm; wing a narrow rim, c. 0.2 mm, 1/8 of nutlet width, opaque, more than one cell thick; styles 1 mm. Hexaploid: 2n=84.
Distribution China northwestern Yunnan, Lijiang, Zhongdian: southwestern Sichuan, Muli: also doubtfully recorded from western Hubei, eastern Xizang (Tibet), ?Gansu, ?Qinghai (in Li & Skvortsov 1999).
Habitat Broad-leaved forests and thickets, usually on limestone at 2400–4000 m asl.
USDA Hardiness Zone 6-7
Taxonomic note From the description in Flora of China (Li & Skvortsov 1999), Betula delavayi var. polyneura Hu closely resembles both B. delavayi and B. calcicola, but has more numerous veins; the status of this form is uncertain, and it may represent a distinct taxon. Betula delavayi var. microstachya P.C.Li, from western Sichuan, likewise deserves further study (Betula bomiensis is treated by Flora of China as a synonym of this variety).
With arching stems and handsome foliage, Betula delavayi is one of a poorly understood complex of western Chinese species that includes B. potaninii, B. calcicola and B. bomiensis, and which are separable largely by chromosome number and geographical distribution as well as minor morphological characters. Betula delavayi is distinguished by its ovate-elliptic, firm, leathery leaves with mostly 10–14 pairs of veins, and especially by the numerous small reddish glands on the underside of the leaf. The leaves of the other species mentioned are leathery, but totally eglandular and much more corrugated in appearance: those of B. potaninii have more numerous veins (9–21 pairs) and those of B. bomiensis are smaller, while B. calcicola – for many years treated as a variety of either B. delavayi or B. forrestii – can be distinguished by its much hairier shoots and usually much broader, more leathery leaves. In the wild Betula delavayi has been described as a tree of up to 12 m (McAllister & Ashburner 2013; Grey-Wilson 1988). Flora of China gives the height of B. delavayi as up to 8 m, but Lancaster described climbing a tree of about approx. 12 m and George Forrest similarly annotated some of his specimens as being up to that height.
Most collections identifiable as Betula delavayi, and all material known in cultivation, come from the limestone mountains of the Lijiang range in northwest Yunnan. The species was described from specimens collected by Père Delavay (Jean Marie Delavay, 1834–1895) above Mo so yn (Lankong), in Yunnan. However, several specimens from the Zongdian area, also in northwest Yunnan (Forrest 22036, 30831) certainly belong to this species, as do others from southwest Sichuan (see McAllister & Ashburner 2013). In Flora of China (Li & Skvortsov 1999), Betula delavayi is also cited for western Hubei, eastern Xizang (Tibet), and annotated ‘?Gansu, ?Qinghai’, but confusion with other species (especially B. bomiensis) and simple misidentifications of such a poorly understood species makes its complete distribution difficult to determine from the literature. Specimens collected near Lijiang by George Forrest, described as var. forrestii by Wright Smith, do not differ significantly from Delavay’s material.
To date the species has been little planted, but experience suggests that it requires soil which is well aerated yet never becomes too dry. It seems most likely to thrive in maritime areas on humus-rich soils. In this it appears to be similar to B. calcicola and will succeed in conditions similar to those required by rhododendrons, although it would be expected to survive on soils with higher pH. Cuttings of young plants root relatively easily and viable seed has been produced in cultivation where two clones have been grown together.