Tuesday, May 8, 2018

[Botany • 2018] Mazus sunhangii (Mazaceae) • A New Species Discovered in Central China Appears to Be Highly Endangered

Mazus sunhangii  D. G. Zhang & T. Deng

in Deng, Zhang, Kim, et al., 2016. 

Mazus sunhangii, a new species of Mazaceae from central China is described and illustrated based on evidence from morphology and molecular phylogeny. This new species is morphologically similar to M. puchellus and M. omeiensis but differs in erect habit, inflorescence position, leaf pattern and corolla color. Phylogenetic analysis based on four chloroplast DNA regions (rbcL, rps16, trnL-F, and psbA-trnH) identified the new species as the independent lineage sister to the other East Asian Mazus species. The new species is known only from a single location in Mt. Shennongjia area in northwest Hubei province, at the elevation of 760 m. The species grows on the limestone cliff, and, because a tourist arterial highway is located along this cliff, its habitat can be easily disturbed or destroyed. We propose that the only known species location is recognized as critical habitat (i.e., as the habitat required to ensure the persistence of a species) and the species listed as Critically Endangered based on the International Union for Conservation of Nature Red List Categories and Criteria B2a.

Fig 2. Images of living plants of Mazus sunhangii D. G. Zhang & T. Deng.
A, habitat; B, population; C, habit; D, individual; E, inflorescence; F, flower; G, ovary and style; H, stamen. 

Mazus sunhangii D. G. Zhang & T. Deng, sp. nov. 

Distribution and habitat: Mazus sunhangii is so far known only from a single location in the SNNR, the northwest part of Hubei Province, central China (Fig 4). The climate here belongs to subtropical monsoon, which is cool, foggy and humid (annual rainfall ca. 1770 mm). The only discovered population comprises less than 500 individuals growing along the steep moist limestone cliff up to the height of 200 m (Fig 2A and 2B). The total area occupied by the species is not more than 2 km. The other two species occupying the same habitat with M. sunhangii are Eriophorum comosum Wall. and Adiantum capillus-veneris L. The valley at the base of the cliff is covered by evergreen and deciduous mixed forest dominated by Cyclobalanopsis gracilis, Platycarya strobilacea and Carpinus viminea.

Etymology: The species is named in honor of Prof. Hang Sun, a Chinese botanist who made a significant contribution to our knowledge of the flora of China.

Tao Deng, Xiao-Shuang Zhang, Changkyun Kim, Jian-Wen Zhang, Dai-Gui Zhang and Sergei Volis. 2016. Mazus sunhangii (Mazaceae), A New Species Discovered in Central China Appears to Be Highly Endangered.  PLoS ONE. 11(10): e0163581.  DOI: 10.1371/journal.pone.0163581