Picea retroflexa Mast.

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Credits

Article from New Trees by John Grimshaw & Ross Bayton

Recommended citation
'Picea retroflexa' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/picea/picea-retroflexa/). Accessed 2024-03-28.

Genus

Common Names

  • Tapao Shan Spruce

Synonyms

  • P. asperata Mast. var. retroflexa (Mast.) W.C. Cheng

Glossary

Critically Endangered
IUCN Red List conservation category: ‘facing an extremely high risk of extinction in the wild’.
glaucous
Grey-blue often from superficial layer of wax (bloom).

References

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Credits

Article from New Trees by John Grimshaw & Ross Bayton

Recommended citation
'Picea retroflexa' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/picea/picea-retroflexa/). Accessed 2024-03-28.

Tree to 45 m, 1–1.5 m dbh. Bark light brown, smooth then flaking in young trees, becoming grey-brown or grey, rough and scaly. Crown columnar or narrowly conical. Branchlets short, firm, thick, light brown or orange-brown, glabrous or with ferruginous pubescence, pulvini strongly developed; vegetative buds resinous. Leaves spreading radially, curved forwards, light green or glaucous-green, pungent, quadrangular or transversely rhombic in cross-section, (1–)1.2–1.8(–2.5) × (0.12–)0.15–0.2 cm, apex acute. Male strobili 2–3.5 cm long, reddish yellow. Cones terminal, sessile, oval-oblong or cylindrical to conical, 8–13 × 2.5–4 cm, purplish red when immature, purplish or reddish brown when mature, finally shiny brown. Seed scales obovate-oblong, convex, 1.5–2 × 1.2–1.5 cm, upper margins rounded or obtuse, slightly erose-denticulate, straight or slightly reflexed. Seeds dark brown or red-brown, ovoid-oblong, 0.3–0.4 cm long, wings pale brown or yellowish brown, obovate-oblong, 1–1.5 × 0.5–0.7 cm. Farjon 1990. Distribution CHINA: western Sichuan (north and west of Kangding). Habitat Subalpine forest on north-facing slopes between 3000 and 4000 m asl. USDA Hardiness Zone 6. Conservation status Vulnerable. Illustration Farjon 1990. Cross-references B181 (as P. asperata var. retroflexa), K203.

According to Bean (1976b), Picea retroflexa was introduced by Wilson (Wilson 4083), and it seems probable that most if not all of the specimens in cultivation today are derived from this collection, as no recent gatherings have been traced. In the wild, according to Wilson (Sargent 1916), it makes large gaunt trees with rather glaucous foliage, but in cultivation the leaves tend to be green. It has a limited presence in the United Kingdom, the two largest specimens having been measured at 19 and 15 m in Windsor Great Park in 2000 (Johnson 2003). The Wilson collection is also grown in North America (for example, at the Morton Arboretum).

Related to this species and the other members of the Picea asperata complex is P. aurantiaca Mast., discovered by Wilson in western Sichuan in 1903. This appears to have a narrow range southwest of Kangding (Rushforth 1987a), where it is considered to be endangered. According to Wilson (Sargent 1916), the mature trees are very narrow, with pale grey or whitish bark. The name relates to the orange coloration of the new shoots, which fade slowly to grey after several years. This interesting-sounding tree has a toe-hold in cultivation, with one mature specimen listed in the catalogue of the Arnold Arboretum (Anon. 2003). Material has been distributed from there to the Hørsholm Arboretum, Denmark, resulting in a small number of grafted specimens in Europe (K. Rushforth, pers. comm. 2007). The identity of other specimens in the P. asperata complex collected by Wilson should be investigated.