Pinus wangii

Hu et W.C. Cheng 1948

Common names

毛枝五针松 maozhi wuzhensong [Chinese], Guangdong white pine, thông năm lá thừa lưu [Vietnamese].

Taxonomic notes

Synonym: Pinus parviflora var. wangii (Hu & W.C.Cheng) Eckenw. 2009. Type: China, Yunnan, Xichou Xian, Fadou, C.W. Wang 85830. Businský (2004), relying on ordination of a small group of morphological characters, describes three subspecies: a type, a subsp. varifolia previously described as a species but not generally recognized, and P. kwangtungensis as a subspecies of P. wangii. He also segregates two new species from P. wangii: P. eremitana and P. orthophylla. All of these taxa, except P. kwangtungensis, are now generally treated as synonyms of the widespread and diverse eastern Chinese/Indochinese species P. fenzeliana.

For discussion of systematics relative to other species in subsection Strobus, see Phylogeny of East Asian white pines.

Description

Monoecious evergreen trees to 20 m tall and 60 cm dbh, typically with a umbrella-shaped or irregular crown of wide-spreading branches. Bark first smooth and thin, later becoming scaly and flaky, darkening to dark brown or gray-brown. Twigs slender, red-brown, initially pubescent, glabrous or with remnants of pubescence in grooves in the second to third year, turning gray-brown. Buds ovoid to cylindrical, not resinous. Leaves in fascicles of 5, held by deciduous sheaths of flimsy, brown scales, spreading or curved slightly towards the twig, 2.5-6 cm long, pliant, straight or curved, 1-1.5 mm thick, green, with stomatal lines on the two adaxial surfaces. Pollen cones in small clusters, short cylindrical. Seed cones variable in size and shape, from short ovoid to long cylindrical, initially erect on stout peduncles, becoming curved down to pendulous, 4-10(-15) cm long, solitary or in 2's or 3's. Seed scales soft woody, flexible at base, cuneate to oblong; apophyses rhombic, curved or more or less straight, not recurved, ripening to yellowish brown or dark brown, weathering gray-brown; apex thin and straight or slightly incurved, rarely upcurved; umbo terminal, small and sunken or obtuse. Seeds obovoid or ellipsoid, 8-10 × 6 mm, wing ca. 16 × 7 mm (Farjon 2010).

"It has many characters in common with both P. kwangtungensis and P. fenzeliana, the principal differences are the length of the needles, size of the cones (slightly shorter and smaller than P. kwangtungensis or P. fenzeliana) and the colour and degree of pubescence of the first year shoots" (Luu and Thomas 2004).

Distribution and Ecology

China: SE Yunnan (Malipo, Maguan, Xichou); possibly also in Viet Nam--there's been considerable debate on this point that as of 2017 remains unresolved (Farjon 1998, Hiep et al. 2004, Luu and Thomas 2004, Loc et al. 2017). Occurs in a monsoonal tropical climate at elevations of 500-1,800 m in steep, cliffy limestone karst areas, often associated with Quercus variabilis and other, mostly small-leaved, evergreen trees and shrubs (Hiep et al. 2004, Farjon 2010). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001).

A 2011 attempt to inventory the species found it extant in three counties of Wenshan prefecture: Xichou, Maguan and Malipo. A total of 358 individuals were found, with a timber volume of 22.8 m³. Malipo county was the distribution center with 335 individuals; Xichou county and Maguan county had 13 individuals and 10 individuals respectively. The species was found to be severely threatened by illegal logging (Yun et al. 2012). As of 2013, P. wangii clearly warranted "Endangered" status. It was then known from just nine herbarium collections from four localities, with an extent of occurrence of 1,633 km² and an area of occupancy of 80 km² or less. No conservation reserves or actions have been put in place to prevent its further decline (Farjon 2013).

Remarkable Specimens

Ethnobotany

White pines everywhere are highly regarded for their attractive, easily worked wood, and there seems to have been some timber exploitation of this rare species, but no specifics are known (Farjon 2010). It is rarely seen outside of major botanical gardens.

Observations

Remarks

The epithet remembers Chinese botanist C.W. Wang, who collected the type specimen.

Citations

Businský, R. 2004. A revision of the Asian Pinus subsection Strobus (Pinaceae). Willdenowia 34(1):209–257.

Farjon, Aljos. 2010. A Handbook of the World's Conifers. Leiden, Netherlands: Brill Academic Publishers.

Farjon, Aljos. 2013. Pinus wangii. The IUCN Red List of Threatened Species 2013: e.T32368A2816540. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T32368A2816540.en. Downloaded on 19 May 2020.

Hiep, N. T., P. K. Loc, N. D. T. Luu, P. I. Thomas, A. Farjon, L. V. Averyanov, and J. C. Regalado Jr. 2004. Vietnam Conifers: Conservation Status Review 2004. Fauna & Flora International, Vietnam Programme, Hanoi.

Hu, H. H. and W C. Cheng. 1948. Some new trees from Yunnan. Bulletin of the Fan Memorial Institute of Biology, ser. 2, 1(2):191.

Loc, P. K., P. V. Te, P. K. Long, J. Regalado, and L. V. Averyanov. 2017. Native conifers of Vietnam – a review. Pakistan Journal of Botany 49(5):2037–2068.

Yun, Z., J. Hong, Y. WenZhong, Z. ShanShan, and X. ZhenYong. 2012. Study on stock of Pinus wangii, an extremely small population species. Journal of West China Forestry Science. 41(3):80–83.

See also