Thursday, April 23, 2020

[Botany • 2020] Crepidomanes shenzhenense (Subg. Crepidomanes; Hymenophyllaceae) • A New Filmy Fern Species from Guangdong, southern China

Crepidomanes shenzhenense Wang Hui & X. Yun Wang

in Wang, Zhao, Ravi & Lu, 2020. 

A new filmy fern, Crepidomanes shenzhenense (Hymenophyllaceae) is described from Shenzhen, Guangdong, southern China. Crepidomanes shenzhenense is a tiny fern characterized by having a broadly obovate lamina only with internal false veinlets and crenate to dissected margins of involucre lips. The new species is presently known from two localities in Shenzhen. The distinctiveness between the new species and three relevatives, C. parvifolium, C. megistostomum and C. latealatum complex, are presented in detail.

Keywords: Endangered species, filmy ferns, southern China, Pteridophytes

FIGURE 1. Crepidomanes shenzhenense Wang Hui & X. Yun Wang.
—A–B. Habits of the new species in situ.—C. Fronds with sori.—D–F. Sori from different individuals.—F. Internal false veinlets.—H. Portion of stipe showing hairs.

FIGURE 2. Crepidomanes shenzhenense Wang Hui & X. Yun Wang.
—A. Habit.—B. Portion of ultimate segment showing internal false veinlets and retused apex.— C. Internal false veinlets.—D. Hairs on the stipe.—E. Sorus with sporangia.—F. Sorus without sporangia.
(Drown by Cui Ding-han based on holotype)

Crepidomanes shenzhenense Wang Hui & X. Yun Wang, sp. nov. 

Diagnosis:— Crepidomanes shenzhenense resembles C. latealatum (van den Bosch 1863: 138) Copeland (1938: 60) but differs from the latter in having broadly obovate (vs. ovate to oblong or triangular) lamina, 1–4 (vs. 5–12) pairs of pinnae, involucre lips margin crenate to dissected (vs. entire), and sori only borne on the long acroscopic (vs. short acroscopic) segment .

Geographical distribution:— Crepidomanes shenzhenense is known only from two localities, Mt. Yangtaishan and Mt. Wutongshan, Shenzhen City, Guangdong, southern China, based on our fieldwork and herbarium investigations. 

Ecology:— Epilithic on wet granitic rock and cliff, near mountain stream in humid, under well shaded evergreen forest.

Etymology:— The specific epithet is from Shenzhen, a city located in southern China, where the new species was discovered.

Hui Wang, Guo-Hua Zhao, Baskaran Xavier Ravi and Shu-Gang Lu. 2020. Crepidomanes shenzhenense (Subg. Crepidomanes; Hymenophyllaceae), A New Filmy Fern Species from Guangdong, southern China. Phytotaxa. 440(2); 101–107. DOI: 10.11646/phytotaxa.440.2.2