Amentotaxus yunnanensis

H.L. Li 1952 (p. 197)

Common names

Vietnamese: Thông tre vân nam, Sam bông (FIPI 1996).

Taxonomic notes

Syn.: Amentotaxus hatuyenensis Hiep 1996. Hiep's species was only known from a few locations in Viet Nam and differed from A. yunnanensis only in the color of the stomatal bands. Molecular studies (Phan et al. 2014, Gao et al. 2016) subsequently showed that collections of A. hatuyenensis fall entirely within the range of variation seen in A. yunnanensis.

Description

Tree to 20 m tall and 25 cm dbh, with a wide, ovate crown. "Twigs opposite, smooth or slightly lined, green or glaucous, turning yellow, yellowish or yellow-grey after 2-3 years. Leaves subopposite, arranged into 2 rows, 3.5-10(15) cm long and 8-15 mm wide, narrowly lanceolate or linear, straight or curved on upper part, obtuse or pointed with subrounded or broadly cuneate base. Margin slightly revolute. Midrib evident above, flat beneath, two bands of stomata on both surfaces, usually white or grey, 2-4 mm wide. In leaf-buds, band of stomata often narrower. Female cone spike-like, with 4-6 spikes at the branch-tips, 10-15 cm long. Each stamen bears 4-8 anthers (usually 6-7). Fruit often solitary on the annual branches, downcurved, ovate, 2.2-2.8 cm long and 1.4 cm wide. Pericarp violet-red when mature, slightly covered with white powder. Stalk stout, 1.5 cm long, lower part flat, upper part quadrangular" (FIPI 1996).

Distribution and Ecology

Viet Nam and China: Yunnan. In Viet Nam found in primary forest of Lao Kai province, above 700 m elevation on Hoang Lien Son mountain. Mesic tree, shade-tolerant when young. Usually mixed with Chamaecyparis hodginsii or Podocarpus neriifolius (FIPI 1996). Hardy to Zone 9 (cold hardiness limit between -6.6°C and -1.1°C) (Bannister and Neuner 2001).

Distribution data from GBIF (2022). A. yunnanensis is green.

The IUCN (2017) assessed A. yunnanensis as "vulnerable" based on (1) an ongoing but gradual population decline of 30-50% in the past 75 years, and (2) a relatively wide area of occurrence in Viet Nam, considerably greater than in Yunnan, where it is still assessed as "Endangered".

Remarkable Specimens

No data as of 2023.02.23.

Ethnobotany

Wood used for furniture. Seeds contain oil. Can be planted as a shade or decorative tree (FIPI 1996).

Observations

In Viet Nam, where it is endangered, it is protected in Hoang Lien Son Nature Reserve (FIPI 1996).

Remarks

The epithet refers to China: Yunnan.

Citations

Gao L.M., Y. Li, L. K. Phan, L. J. Yan, P. Thomas, K. P. Long, M. Möller, and D. Z. Li. 2016. DNA barcoding of East Asian Amentotaxus (Taxaceae): Potential new species and implications for conservation. Journal of Systematics and Evolution 55(1):16–24.

Hiep, N.T. 1996. Flore du Cambodge, Laos et Viet Nam 28:126.

Li Hui-Lin. 1952. A taxonomic review of the genus Amentotaxus. Journal of the Arnold Arboretum 33:192-198. Available: Biodiversity Heritage Library, accessed 2021.12.19.

Phan K. L., K. L. Phan, T. M. L. Le, and G. S. Nguyen. 2014. Molecular characterization of Amentotaxus hatuyenensis N.T. Hiep (Taxaceae) based on ITS1 partial sequence. VNU Journal of Science: Natural Sciences and Technology 30(3S):46–52.

See also

The species account at Threatened Conifers of the World.

Nguyen Tien Hiep, Phan Ke Loc, Nguyen Duc To Luu, Philip Ian Thomas, Aljos Farjon, Leonid Averyanov, and Jacinto Regalado Jr. 2004. Vietnam Conifers: Conservation Status Review 2004. Hanoi: Fauna & Flora International, Vietnam Programme.

Luu, Nguyen Duc To and Philip Ian Thomas. 2004. Cay La Kim Vietnam / Conifers of Vietnam. Darwin Initiative. ISBN 1 872291 64 3. Available: http://www.ceh.ac.uk/sections/bm/conifer_manual.html, accessed 2006.03.08, now defunct. The authors provide a description, range map, conservation status, drawings and photos, and a wealth of additional information.