Ceratopteris baguangensis F. G. Wang & Zi Xiang Li

Li, Zixiang, Xia, Zengqiang, Lin, Lin, He, Chunmei, Luo, Lin, Xing, Fuwu & Wang, Faguo, 2024, Ceratopteris baguangensis (Pteridaceae), a new species of Ceratopteris from Guangdong, China, Phytotaxa 658 (2), pp. 216-226 : 218

Ceratopteris baguangensis F. G. Wang & Zi Xiang Li , sp. nov. ( Figs. 1–2 ).

Type:— CHINA. Guangdong Province, Shenzhen City, Dapeng Peninsula, Baguang Heritiera littoralia Wetland Park , 30 March 2023, Faguo Wang & Zixiang Li 6832 (holotype, IBSC-903804!).

Diagnosis: —Morphologically, Ceratopteris baguangensis shares some similarities with C. thalictroides and C. oblongiloba , such as the shape and size of the stipe, blades, and lobes in the fertile fronds. However, C. baguangensis has significantly narrower, shorter, more involute lobes and nearly palmately divided pinnae in the sterile leave, distinguishing it from C. thalictroides and C. oblongiloba (see Table 1 ).

Description: —Plant perennial, juicy, and soft, 26.5–35 cm tall. Rhizomes: short and erect, borne in a cluster of thick roots in the silt. Fronds: clusters, dimorphic. Sterile fronds: 22–35 cm long; stipe 5–15 cm long, 0.5–1 cm wide at base, green, terete, fleshy, smooth; blades obtriangular or narrowly oblong, 12–30 cm long, 12–20 cm wide, apex acuminate, base rounded–cuneate, 2–3 pinnate; pinnae 3–8 pairs, oblique, stipitate, obtriangular, nearly palmately divided, 3–5 cm long, 3 cm wide; lobes 2–5 pairs, alternate, oblique, stipitate, apex acuminate, acute, narrowly linear, revolute up to the main vein; ultimate lobe linear to acuminate, 1–3 cm long, ca. 0.2 cm wide. Fertile fronds: 25–40 cm long; stipes 8–20 cm long, 0.5–1 cm wide at base, green, terete, fleshy, smooth; blades obtriangular or narrowly oblong, 15–30 cm long, 12–20 cm wide, apex acuminate, base rounded–cuneate or rounded–truncate 3–5 pinnate; 6–9 pinnae pairs, oblique, obtriangular; lobes 3–8 pairs, incurved, narrowly linear, up to 2–8 cm long, up to 3–5 cm wide, involute; ultimate lobe linear to acuminate, 0.5–1.5 cm long, ca. 0.2 cm wide, close to each other. Spores: cylindrical, 50–65 μm in diameter, surface with parallel stripes ( Fig. 2 ). Tetraploid, 2n = ca. 154 or 156 ( Fig. 3 ).

Distribution and Habitat:— Ceratopteris baguangensis was first discovered in Baguang, Dapeng Peninsula of Shenzhen. Around 20 mature individuals were found growing in waters with a pH of 6.8 at Baguang Heritiera littoralia Wetland Park.

Etymology:— The park where it was found is called Baguang Heritiera littoralia Wetland Park , and the name is derived from the toponym.

Figures

FIGURE 1. The morphology of Ceratopteris baguangensis (photographed by Fa-Guo Wang). A. Mature plant in habitat; surrounded by other plants; B. Face of sterile fronds; C. Back of sterile fronds; D. The living plants; E. Fertile fronds.

FIGURE 2. Ceratopteris baguangensis F. G. Wang & Zi Xiang Li. a. Mature plant; b. Face of sterile fronds; c. Back of sterile fronds; d. Face of fertile fronds; e. Back of fertile fronds; f. Enlarged fertile frond anatomy/portion for sporangium; g. Spore; Drawn by Yunxiao Liu.

FIGURE 3. Chromosome number of Ceratopteris baguangensis in mitotic root-tip cells. (A) Metaphase chromosome of the tetraploid, 2n = 154 or 156; (B) Lined drawing of Figure A.