Dryopteris sukungiana Z. Y. Zuo, 2022

Zuo, Zheng-Yu, Lu, Jin-Mei, Wang, Yue-Hua & Li, De-Zhu, 2022, Dryopteris sukungiana (Dryopteridaceae), a new species of the D. sparsa complex from Southwest China, Phytotaxa 533 (5), pp. 256-266 : 260-264

Dryopteris sukungiana Z. Y. Zuo , sp. nov. ( Figs. 1 & 2 ), in Chinese 云Dzfl毛ƃ (yún nán lín máo jué).

Type:— CHINA. Yunnan: Maguan , 103°59’ E / 22°50’ N, 1950 m alt., 22 June 2021, Z. Y. Zuo 4660 (holotype KUN-1519949; isotypes HITBC-0061304, KUN-1519950, PE-02354809) .

Diagnosis:— The scales of Dryopteris sukungiana are blackish brown and spreading ( Fig. 3E ), which is different from all other species in the D. sparsa complex ( Fig. 3D, 3F ). Dryopteris sukungiana is similar to the ‘typical’ Sino-Himalayan D. sparsa with erect rhizomes, deltoid or pentagonal tripinnatifid to tripinnate lamina, basal pinnae abruptly broadened toward the base ( Fig. 3A, 3B ), but differs in having glandular hairs and small fibrillose scales on the abaxial surface of the lamina and the indusia ( Fig. 3G, 3H ). It resembles the Sino-Japanese D. sparsa in the catadromous pinnules of the second pair of pinnae and glandular hairs on the indusia and the abaxial surface of the lamina ( Fig. 3H, 3I ); however, the lamina of the Sino-Japanese D. sparsa is ovate-deltoid, and the basal pinnae are gradually broadened ( Fig. 3C ). Dryopteris sukungiana also looks like D. angustipalea Darnaedi, M. Kato & K. Iwats. (1989a: 308) ; however, the latter is endemic to Indonesia, and in which the lamina is ovate-deltoid, the basal pinnae are gradually broadened toward the base, rachis and costae are glabrous.

Plants 30–60 cm tall. Rhizome erect, up to 8 cm long and 2 cm in diameter, clothed with blackish brown, linear- or ovate-lanceolate, spreading, entire scales. Stipe slightly shorter than lamina, ca. 17–38 cm, covered with glandular hairs when young, brown at base, with blackish brown linear- or ovate-lanceolate, spreading, entire, scales. Lamina papery, glossy, deltoid or pentagonal, ca. 26–53 × 18–35 cm, tripinnatifid to tripinnate, base not narrowed, apex acuminate, with glandular hairs on abaxial surface. Pinnae 9–17 pairs, deltate-lanceolate, up to 16 × 6 cm, apex caudate-acuminate; Basal 1–3 pairs opposite and alternate upward, oblique, stalked approximately 1–2 cm. Basal pinnae abruptly broadened toward the base. Pinnules 9–23 pairs, margin serrate to lobed, opposite at base and alternate upward, lanceolate to rounded, base broadly cuneate, asymmetrical, apex obtuse to truncate. Basal basiscopic pinnules of basal pinnae longest, ca. 5–8 × 2–3 cm, base widest, 2-pinnate. Pinnules of the second pair of pinnae catadromous. Rachis and costa clothed with glandular hairs and small fibrillose scales. Veins pinnate, forked, distinct on both surfaces. Sori close to costa on pinnules, with a wide sterile belt on both sides of costa distal to sori. Indusia orbicularreniform, entire, with glandular hairs. Reproductive mode and ploidy level: sexual tetraploid.

Additional specimens examined (paratypes): — CHINA. Yunnan: Baoshan , Z. Y. Zuo 1615 & 4937; Cangyuan, Z. Y. Zuo 2862; Kunming, J. M. Lu 179; Longling, X. Cheng et al., FB581 ; Tengchong, Z. Y. Zuo 1498, 1520 & 4949 .

Ecology and geographical distribution: — Dryopteris sukungiana was found in mountain forests at alt. 1900‒ 2450 m in the central, southern, and southwestern parts of Yunnan Province, China, and perhaps in other neighboring areas.

Etymology:— In honor of late Prof. Su-Gong Wu (Su-Kung Wu in Wide-Giles transliteration) (1935-2013), for his contributions to the taxonomic studies on ferns in China, and especially the contributions to collections and studies on the ferns of the Qinghai-Tibet Plateau. He also edited some sections of Dryopteris in Flora Reipublicae Popularis Sinicae and Flora of China.

Figures

FIGURE 1. Photos of Dryopteris sukungiana (Z.Y. Zuo 4660). A. Habit. B. Young plant. C. Rhizome. D. Portion of lamina. E. Sori on ultimate pinnules. F. Glandular hairs on the rachis and costa, an indusium, and small fibrillose scales on the rachis and costa. G. Scales of stipe.

FIGURE 2. Illustration of Dryopteris sukungiana. A. Plant. B. Ultimate pinnule. C. Indusium. D. Scales of stipe. (Drawn by Ling Wang, based on the holotype (Z.Y. Zuo 4660))

FIGURE 3. Morphological comparison of the Sino-Himalayan Dryopteris sparsa (A, D & G), D. sukungiana (B, E & H), and the Sino- Japanese D. sparsa (C, F & I). A–C. Frond. D–F. Scales of stipes. G–I. Details of ultimate pinnule.