Tsuga formosana

Hayata (1908)

Common names

台灣鐵杉 tai wan tie shan [Chinese].

Taxonomic notes

Type: Taiwan, Mt. Morrison, S. Nagasawa, 1905 (holotype US 1053220). Syn: Tsuga chinensis var. formosana (Hayata) H.L.Li & H.Keng, T. chinensis subsp. formosana (Hayata) Silba, T. chinensis var. daibuensis S.S.Ying. Most recent authors have regarded this as a synonym or variety of T. chinensis, but molecular studies have shown it to be sister to T. sieboldii. The most recent common ancestor of the two species dates to approximately 7.8 million years ago, which approximately coincides with the age of the mountains of Taiwan (5-6 million years ago). There is then evidence of more recent introgression of T. formosana by T. sinensis of eastern China, which is plausible because the Taiwan Strait was dewatered during low sea level stands in the Pleistocene. There are comparable examples of introgression among other Taiwan conifers, including Cunninghamia konishii, Psuedotsuga wilsoniana, and Taxus wallichiana (Feng et al. 2021 and sources therein).

Description

Evergreen trees to 50 m tall and 200 cm dbh, with a crown of slender, horizontal, often pendulous branches. Bark dark gray to reddish brown, furrowed. Twigs yellowish, aging pale yellowish gray, hairy in grooves, with prominent pulvini (leaf bases). Leaves spirally arranged but appearing more or less 2-ranked, linear, flat, petiolate, 15-25 mm long, 2-3 mm wide, adaxially grooved, abaxially with 2 whitish stomatal bands, apex rounded or emarginate, a single resin duct beneath the vascular bundle. Seed cones terminal on lateral shoots, ovoid, 1.5-2.5 × 1.2-1.6 cm, the scales woody, persistent, suborbicular, lustrous yellowish brown, the margins slightly irregularly serrate. Seeds 7 mm long including the wing (Li 1975, Wu and Raven 1999, Li and Keng 1993).

Distribution and Ecology

Taiwan: Ilan, Kaoxiung, Miaoli, Nantou, Pingtung, Taichung, and Xinchu Xian (from 22°36'N to 24°29'N and from 120°44'E to 121°161E) at 1250-3536 m elevation. Commonly occurs in mixed broadleaf and conifer forest, dominated by Juniperus and Yushania (HAST 1999).

Remarkable Specimens

Ethnobotany

Observations

Taiwan collections reported for: Yushan National Park (23°28'N, 120°57'E), Lalashan Preserve (121°25'30"E, 24°44'00"N) (HAST 1999). Can be seen in Shei-Pa National Park (HAST 1999). Yushan National Park also looks like a good place to see it.

Remarks

Citations

Feng, Yuan-Yuan, Ting-Ting Shen, Cheng-Cheng Shao, Hong Du, Jin-Hua Ran, and Xiao-Quan Wang. 2021. Phylotranscriptomics reveals the complex evolutionary and biogeographic history of the genus Tsuga with an east Asian-North American disjunct distribution. Molecular Phylogenetics and Evolution 157:107066. https://doi.org/10.1016/j.ympev.2020.107066.

Herbarium of the Research Center For Biodiversity, Academia Sinica, Taipei [HAST]. 1999. Database output at http://www2.sinica.edu.tw:8080/hast/eindex.html, accessed 1999.03.15, now defunct.

Hayata, Bunzo. 1908. New Conifers from Formosa. Gardeners' Chronicle ser. 3, 43:194. Available: Google Books, accessed 2016.02.14.

Li, Hui-Lin and Keng, Hsuan. 1993. Flora of Taiwan, V. 1. Pinaceae, p. 580.

See also