Cephalotaxus harringtonia var. wilsoniana (Hayata) Kitam.
Endemic to Taiwan where logging and the the conversion of native forest to Cryptomeria japonica plantation has caused a decline in the population.
Description
Taxonomic Notes
In the second edition of Flora of Taiwan 1 (1994), as well as in a horticultural compilation (Tripp 1995) this taxon was treated at species rank. In Flora of China Vol. 4 (1999) it is treated as a variety under C. sinensis. The morphology of these species is rather similar, but evidence from DNA appears to point to a closer affinity with the Japanese species C. harringtonii. This classification, first proposed by the Japanese botanist Siro Kitamura, is here accepted as the most likely true reflection of relationships.
Distribution
Endemic to Taiwan. Widely distributed in the following counties: Chiayi, Hsinchu, Hualien, Nantou, Yilan & Taipei.
Habitat and Ecology
This taxon occurs in deciduous/evergreen forest at middle elevation (ca. 1500–2000m). These forests are dominated by Fagaceae, Lauraceae, Pinaceae (Pinus, Pseudotsuga, Tsuga), and a variety of other trees; C. harringtonii var. wilsoniana forms a small understorey tree tolerant of shade. In more open situations, e.g. after forest disturbance, it can hold its own and resprout from the base or roots to form a dense bush.
Human Uses
Rare in cultivation and probably restricted to a few botanic gardens.
Conservation Status
Global status
Endangered B1ab(iii,v)+2ab(iii,v)
Global rationale
This variety has a small extent of occurrence (4375km²) and area of occupancy (294km²), which are within the thresholds for listing as Endangered. The population is severely fragmented and there is continuing decline due to the loss of habitat as a result of clearance to make way for Cryptomeria plantations. It is therefore listed as Endangered under criteria B1and B2.
Global threats
The native forests, in which Cephalotaxus harringtonii var. wilsoniana is a rare tree, have been under pressure of conversion after logging to plantations with mainly Cryptomeriajaponica. The species is known from several localities concentrated, but not restricted, to the northern part of Taiwan, where such conversions have been widespread.
Conservation Actions
It occurs in several reserves including Taroko National Park.
References and further reading
Chia Ju Yang, Ching-Te Chien, Yue Ken Liao, Shun-Ying Chen, Jerry M. Baskin, Carol C. Baskin and Ling-Long Kuo-Huang (2011). Deep simple morphophysiological dormancy in seeds of the basal taxad Cephalotaxus. Seed Science Research 21:215-226.
Hao, D.C., Xiao P.G., Huang B.-L., Ge G.B. & Yang L. (2008). Interspecific relationships and origins of Taxaceae and Cephalotaxaceae revealed by partitioned Bayesian analyses of chloroplast and nuclear DNA sequences. Plant Systematics and Evolution 276:89-104.
Lu, S.Y. & Pan, F.J. (1996). Rare and Endangered Plants in Taiwan I.
Yang, Y. & Luscombe, D 2013. Cephalotaxus harringtonii var. wilsoniana. The IUCN Red List of Threatened Species. Version 2015.2.
