Cephalotaxus lanceolata (贡山三尖杉, Gongshan plum yew) description

Cephalotaxus lanceolata

K.M.Feng ex W.C.Cheng et al. 1975

Common names

贡山三尖杉 gòng shān sān jiān shān [Chinese], Gongshan plum yew.

Taxonomic notes

Type: China (中国), Yunnan (云南), Gongshan Co. (贡山县), west of Dulong River, 1900 m elevation, in broad-leaved forests near the river, 1959.11.18, K. M. Feng (冯国楣) 24347 (holo PE). Syn: Cephalotaxus fortunei Hook. var. lanceolata Silba 1990; Cephalotaxus talonensis W.C.Cheng & K.M.Feng ex S.G.Lu & X.D.Lang (2013), nom. inval.. This was treated as a good species by both Fu et al. (1999) and Farjon (2010), but Lang et al. (2013) determined that C. lanceolata is an illegitimate name, having previously been applied to a cultivar by Beissner (1901); they resolved the matter by reducing C. lanceolata to synonymy with the similar and more widespread taxon C. griffithii, a determination currently accepted by POWO. However, Yang (2023) rejected this argument, finding that Beissner "never accepted this name in any of his publications". The molecular analysis by Wang et al. (2022) (see Cephalotaxus) found that "Cephalotaxus lanceolata formed a distinct clade separate from C. griffithii, and morphologically differed from C. griffithii by lanceolate leaves and rounded base." That analysis showed that C. griffithii is synonymous with an earlier-named species, C. mannii.

Molecular analysis by Wang et al. (2022) found that C. lanceolata is sister to a clade comprised of C. hainanensis and C. mannii. This is a biogeographically interesting result as these three taxa have adjacent distributions and occupy subtropical and tropical mountains across much of SE Asia (from E India to Hainan Island in China).

Description

Trees to 20 m tall and 40 cm dbh, with an open or rounded crown of pendulous branches. Bark thin, smooth, exfoliating in thin flakes, purple weathering to gray-brown. Twigs slender, grooved between decurrent leaf bases, green turning reddish brown. Leaves pectinately arranged in two rows, the foliar unit forming a V-shape, spreading at 45-70° to twig axis, 4.5-10 cm long, 4-7 mm wide, straight or slightly falcate, narrowly lanceolate to linear-lanceolate, nearly sessile, base obtuse, apex acuminate or cuspidate, coriaceous, dark green above, pale green with two whitish stomatal bands below, upper midrib raised and continuous and 0.6 mm wide, lower midrib flat and slightly wider, stomatal bands each with 15-20 intermittent lines and bordered by slightly revolute leaf margins. Pollen cones not described. Seed cones solitary at base of lateral foliage twigs on 15-20 mm long slender peduncles. Fertilized ovules surrounded by a green aril 35-45 × 20-25 mm at maturity, when it becomes soft and turns greenish-brown with indistinct longitudinal striations, with a short mucronate apex. Seeds obovoid or ellipsoid, 30-40 × 16-20 mm. Seed maturity September to November (Fu et al. 1999, Farjon 2010).

Distribution and Ecology

China: Yunnan. This is the most restricted taxon of Cephalotaxus, only known to occur in extreme NW Yunnan at about (27.7°N, 98.3°E), in the headwaters of the Dulong River. The area is less than 5 km E of the Myanmar border, so the species may occur in Myanmar as well. The species is found scattered in evergreen broad-leaved forest at elevations of 1450-1970 m. Very little is known about its ecology (Farjon 2010, Yang and Liao 2018).

This species was most recently (2010) assessed as "Endangered". It has a very limited extent of occurrence and area of occupancy, with only one known population. There are mostly just seedlings left in the single known location, suggesting recent reductions in the population of reproductively mature trees. Although it may occur in adjoining parts of Myanmar, logging and deforestation have recently occurred in that area as well. These disturbances are likely to continue, with habitat being converted to agriculture and remaining forest degraded by timber harvest (although large-scale logging is now banned in the Chinese part of its range) and firewood collection. The species is not known to occur in any protected areas, nor is it the subject of any conservation programs. It might qualify as "Critically Endangered" (Yang and Liao 2018).

Remarkable Specimens

No data as of 2024.08.05.

Ethnobotany

Timber harvesting and clearing have been observed by botanists visiting the area, so there is probably some incidental harvest of this small tree as firewood or for local use.

Several alkaloids unique to C. lanceolata show high levels of activity against human tumor cell lines (He et al. 2013).

Observations

No cultivated specimens are known at this time (mid-2024) and access to the species in habitat would be difficult and would likely require collaboration with Chinese authorities.

Remarks

The epithet refers to the lanceolate leaves.

Citations

Beissner, L. 1901. Mitteilungen über Coniferen, Die Taxales. Mitteilungen der Deutschen Dendrologischen Gesellschaft 10: 73–74 & 117.

Cheng, Wan-Chun, and Li-Guo Fu. 1975. Gymnospermae Sinicae. Acta Phytotaxonomica Sinica 13(4):56–90.

He, Yi‐Ren, Yun‐Heng Shen, Bo Li, Bo Li, Lu Lu, Jun‐Mian Tian, and Wei‐Dong Zhang. 2013. Alkaloids from Cephalotaxus lanceolata and their cytotoxicities. Chemistry & Biodiversity 10(4):584-595.

Lang, Xue-Dong, Jian-Rong Su, Shu-Gang Lu, and Zhi-Jun Zhang. 2013. A taxonomic revision of the genus Cephalotaxus (Taxaceae). Phytotaxa 84(1): 1-24.

Liao, W. and Y. Yang. 2013. Cephalotaxus mannii. The IUCN Red List of Threatened Species 2013: e.T18625568A2804770. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T18625568A2804770.en, accessed on 2024.08.05.

Wang, Jie, Chao-Nan Fu, Zhi-Qiong Mo, Michael Möller, Jun-Bo Yang, Zhi-Rong Zhang, De-Zhu Li, and Lian-Ming Gao. 2022. Testing the Complete Plastome for Species Discrimination, Cryptic Species Discovery and Phylogenetic Resolution in Cephalotaxus (Cephalotaxaceae). Frontiers in Plant Science 13: 768810. https://doi.org/10.3389/fpls.2022.768810, accessed 2024.08.26.

Yang, Yong. 2023. Taxonomic Status and Nomenclature of Cephalotaxus lanceolata (Cephalotaxaceae). PhytoKeys 222:173–77. https://doi.org/10.3897/phytokeys.222.101974.

Yang, Y. and W-B. Liao. 2018. Cephalotaxus lanceolata, from Threatened Conifers of the World, accessed 2024.08.25.

Zhang, Jian-Wei, Ashalata D’Rozario, Xiao-Qing Liang, and Zhe-Kun Zhou. 2019. Middle Miocene Cephalotaxus (Taxaceae) from Yunnan, southwest China, and its implications to taxonomy and evolution of the genus. Palaeoworld 28(3): 381-402.