Whittieria hengduanensis Z. L. Liang & Li Bing Zhang, 2024

Liang, Zhen-Long & Zhang, Li-Bing, 2024, Discovery of Whittieria hengduanensis sp. nov. (Ophioglossaceae) from Southwest China demonstrates a unique intercontinental disjunct pattern in plants between the Himalaya and the Americas, PhytoKeys 249, pp. 27-36 : 27-36

Whittieria hengduanensis Z. L. Liang & Li Bing Zhang sp. nov.

Figs 2 , 3

Type.

China • Sichuan: Yajiang County, Jiaonibao Village , elev. 2750 m, 30°6'10.93″N, 101°1'49.79″E, in the shrubs in dry and hot river valleys, 15 July 2021, Z.-L. Liang, L.-S. Jiang & Q. Yu LZL 1959 (holotype CDBI!) .

Diagnosis.

Whittieria hengduanensis is similar to W. engelmannii but the former has up to 25 (– 50) roots per rhizome and 10–20 large areolae per trophophore, whereas the latter has fewer than 15 roots per rhizome and 0–8 areolae per trophophore.

Description.

Plants 10–13 cm tall. Rhizomes erect, cylindrical, diam. 6–7 mm, with numerous black residual trophophore stalks. Leaves 1–2 per rhizome. Roots fleshy, up to 25 (– 50) per rhizome, ca. 0.6 mm diam. Leaf stalks 4.5–7.5 cm long, 1.5–2 mm diam.; the lower part is buried in the soil, grey. Trophophores nearly circular to ovate, papery, 1.6–6 cm long, 1–3 cm broad at the middle, apex acute, narrowed toward the base. Venation complex-reticulate (also called “ double venation ” with small areolae inside a large areola), with included veinlets. Sporophores arising at ground level, the base is slightly attached to sporophores; stalks 3.5–7 cm long; spike 1.2–1.8 cm long, ca. 2.5 mm diam., 16–23 pairs of sporangia per spike.

Geographical distribution.

This species is found in western Sichuan (Batang, Daocheng, Daofu, Derong, Maerkang, Xiangcheng, Yajiang, Yuexi), northwestern Yunnan (Lijiang, etc.), and eastern Xizang (Mangkang, Zayu).

Habitat.

This species grows in basic soil under shrubs in dry and hot river valleys at elevations of 2500–4000 m.

IUCN Red List category.

Based on the field investigations, this species has a relatively wide distribution and large population sizes in southwest China and should be classified as Least Concern (LC), based on current information and following the International Union for Conservation of Nature and Natural Resources guidelines ( IUCN 2024).

Etymology.

The species epithet henduanensis is based on the distribution of this species in the Hengduan Mountain.

Additional specimens examined.

China • Sichuan: Daocheng county , Aug. 23, 1937, T. T. Yu 12889 ( PE 01622937 ) ; 23 Aug. 1981, Qingzang Exp. 4234 ( PE 01384314 ) • Aug. 17, 1973, s. c. 2519 ( KUN 0803070 2519) • Daofu , 18 Sept. 1934, Harry Smith 12236 ( PE 00405282 ) • 16 Aug. 1960, Sichuan Drug Exp. 15532 ( NAS 00143448 ) • Derong , 03 Aug. 1981, Qingzang Exp. 3174 ( PE 01384316 , PE 01384315 , HITBC 053830 ) • Maerkang , 18 Jul. 1960, Sichuan Drug Exp. 22092 ( NAS 00143451 ) • Yuexi , 22 Sept. 1960, Sichuan Drug Exp. 26220 ( NAS 00143450 ) • Xiangcheng , 31 Jul. 1981, Qingzang Exp. 3115 ( PE 01384313 , HITBC 053829 ) • 12 Sept. 1937, T. T. Yu 13319 ( PE 00405281 , PE 00405283 , PE 00405286 ) • Xizang: Zayu , Sept. 1935, C. W. Wang 66172 ( PE 00405289 ) ; Sept. 1935, C. W. Wang 66236 ( KUN 0803067 ) • 13 Aug. 1961, Xizang Complex Exp. 2703 ( PE 00405290 ) • 16 Aug. 1965, Yongtian Zhang & Kaiyong Lang 1541 ( KUN 0803072 ) • Yunnan: Lijiang , 04 Jul. 1965, Jinsha River Exp. 4539 ( PE 01593067 ); T. T. Yu 13319 ( KUN 0803063 ) .

Figures

Figure 2. Whittieria hengduanensis A, B habitat C lower portion of plant showing stem and roots D individuals in different sizes E trophophores and sporophore stalks F sporophore G veins showing complex-reticulate venation.

Figure 3. Whittieria hengduanensis A, B habit C trophophore and base of sporophore D sporophore spike E veins showing complex-reticulate venation.