Arachniodes nigrospinosa (Ching) Ching (1962: 258)

Lu, Ngan Thi, Wei, Hong-Jin, Vuong, Luong Dinh, Toan, Le Chi, Zhang, Li-Bing & Zhang, Liang, 2023, Cyrtomium calcis sp. nov. and six new records of the shield fern family (Dryopteridaceae) from Vietnam, Phytotaxa 583 (1), pp. 15-26 : 23-24

Arachniodes nigrospinosa (Ching) Ching (1962: 258)

≡ Polystichum nigrospinosum Ching (1931: 191) ( Fig. 7 )

Type:— CHINA. Guangdong: Tai-mo Mountain, opposite Hongkong Island, at the foot of granite, elev. ca. 2400 ft, 7 November 1907, C.G. Matthew s.n. (holotype PE 00984039!).

Voucher specimens examined:— VIETNAM. Vinhphuc Province : Tamdao National Park , Tam Dao Town to Rung Rinh Peak (The first Peak) and nearly Thach Ban Peak, elev. 1000–1300 m, 7 November 2009, Pingfong Lu et al. 19380 ( VNMN!) .

Distribution and habitat:— China (Guangdong, Guangxi, Guizhou, Taiwan), Vietnam (Vinhphuc). In ravines, on shaded wet rocks, forests; 500–1500 m.

Notes:—It is rare in Vietnam and only found in Tamdao National Park (ca. 80 km from Hanoi). Arachniodes nigrospinosa is similar to A. festina (Hance) Ching (1962: 257) in having creeping rhizome, 4-pinnate lamina, and papery and ovate-oblong or oblong-rhombic pinnules, but A. nigrospinosa has dense, coal-black, ovate-lanceolate, and spreading scales throughout base to upward (dark or reddish brown, lanceolate, upward glabrescent).

Additional specimens examined:— CHINA. Guizhou: dense shade, 500 m, 8 September 1930, Y. Tsiang 7024 (PE 00984036!); Guangdong: 800 m, October 2001, Yuehong Yan & Fuwu Xing 13239 (PE 01785153!), 700 m, January 2002, Yuehong Yan 504 (HUST 00002190!), 900 m, 01 October 2007, Xile Zhou, Hongfeng Chen 855 (HUST 00009827!); Guangxi: 13 November 1981, Dayaoshan Exp. 12514 (IBK 00189331!), 16 February 2016, Hongjin Wei JSL 3701 (CSH0113679!); Taiwan: Nantou , 960 m, 23°52’N, 120°58’E, R. Knapp 3656 (P!).

Figures

FIGURE 7. Arachniodes nigrospinosa (Ching) Ching.—A. Fronds.—B. Portion of rhizome and petiole showing broad-lanceolate and coal-black scales.—C. Abaxial view of portion of lamina showing pinnules and soral positions.—D. Abaxial view of frond.—E. Spore morphology (A–D. photo credits: Cheng-Wei Chen and Ping-Fong Lu).