Cladopus yangjiangensis X. T. Liu, G. Di Chen & B. Hua Chen 2024, sp. nov.
Creators: name: Zhang, Miao
name: Liu, Xiu-Ting
name: Tian, Min
name: Chen, Zhang-Xue
name: Huang, Ying-Lin
name: Chen, Guo-Di
name: Chen, Bing-Hua
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malpighiales
Podostemaceae
Cladopus
Cladopus yangjiangensis

description: Cladopus yangjiangensis X. T. Liu, G. Di Chen & B. Hua Chen sp. nov.
Figs 4, 5, 6, 7, 8
Diagnosis.
Cladopus yangjiangensis shares certain similarities with C. fukienensis and C. austrosinensis, such as comparable ovary lengths, and analogous stigma and capsule shapes. However, it is distinguished by several unique traits. The leaves of C. yangjiangensis are markedly elongated, measuring 18.7–26.7 mm, which is substantially longer than those of C. fukienensis (1.3–5.0 mm) and C. austrosinensis (up to 6 mm). The flowering shoots of C. yangjiangensis also exceed those of other two species, ranging from 4.2 to 13.1 mm, compared to 3.5–6.0 mm in C. fukienensis and 1.6–3.5 mm in C. austrosinensis. Additionally, C. yangjiangensis produces a greater number of bracts, with counts ranging from 20 to 54, in contrast to 12–36 in C. fukienensis and 8–14 in C. austrosinensis. Finally, the root width of C. yangjiangensis is notably narrower, at about 0.4 mm, compared to 0.4–1.3 mm in C. fukienensis and 0.5–1.3 mm in C. austrosinensis (Table 3).
Type.
China • Guangdong: Yangjiang City Yangxi County, Tangkou Town, Tongyou village, elevation 200 m, 21°49'N, 111°28'E, 24 December 2023, XT Liu & GD Chen 0001 (Holotype FNU! barcode FNU 0041314; isotype FNU! barcode FNU 0041315).
Description.
Perennial aquatic herb; roots narrowly ribbon-like, compressed, dorsiventral, succulent, ca. 0.4 mm width, 0.1–0.2 mm thick, adhere to the surface of underwater rocks, brick-red during winter, dark green during reproduction; stem short, arising from root branch axils (Fig. 4); flowering shoots obpyramidal, solitary, erect, 4.2–13.1 mm tall; leaves linear, in rosette on vegetative shoots, 3–8 in number, 18.7–26.7 mm long, deciduous at flowering; leaves on reproductive shoots palmate (also known as bracts), lobes 3–5 digitate, central lobe long, columns two, opposite, overlapping, bracts 20–54, upper leaves larger, diminishing towards apex, 1.5–1.9 × 1.1–2.0 mm, lobes rigid and coarse after water loss; flowers bisexual, solitary at fertile branch apex, enclosed in pale red spathe during early development; spathella globose, acumen short, 1.7 × 0.3 mm; tepals two, broadly linear, acuminate, 0.7–1.1 mm long; stamen single, 1.2–2.4 mm long; filament nearly cylindrical, slightly flattened, 0.9–1.3 mm long; anthers two, elliptical, yellow, ~ 0.6–0.9 mm long; Ovary single, pale yellow-green, ellipsoid, two-chambered, 1.2–1.7 × 0.9–1.1 mm; ovules ovate, 15–23 per chamber, attached to entire placenta (Figs 5, 6); capsule brownish, globose, smooth, 1.1–1.4 mm long; fruit stalk 1.2–1.7 mm long; seeds small, yellow, narrowly ovoid, 0.3–0.5 × 0.1–0.3 mm (Fig. 7).
Distribution and habitat.
Many other plants grow in the surrounding habitat, whose tree layer includes Archidendron clypearia (Fabaceae), Engelhardia roxburghiana (Juglandaceae), Aporosa dioica (Phyllanthaceae), Zanthoxylum avicennae (Rutaceae), Sterculia lanceolata (Malvaceae) and others; the shrub layer includes Acronychia pedunculata (Rutaceae), Rhaphiolepis indica (Rosaceae), Rubus leucanthus (Rosaceae, Ficus pyriformis (Moraceae), Glochidion lanceolarium (Phyllanthaceae), Garcinia oblongifolia (Clusiaceae), Melastoma sanguineum (Melastomataceae), Saurauia tristyla (Actinidiaceae), Adina pilulifera (Rubiaceae), Pavetta hongkongensis (Rubiaceae), and others; the vegetation layer includes Blechnopsis orientalis (Blechnaceae), Plenasium vachellii (Osmundaceae), Acorus gramineus (Acoraceae), Pandanus austrosinensis (Pandanaceae), Alpinia hainanensis (Zingiberaceae), Thysanolaena latifolia (Poaceae), Miscanthus floridulus (Poaceae), Pentasachme caudata (Apocynaceae) and others; and some exotic plants include Stauntonia obovatifoliola (Lardizabalaceae), Phanera erythropoda (Fabaceae), Rourea microphylla (Connaraceae) and others.
Phynology.
Flowering and fruiting season in November to February of the following year.
Etymology.
The Yang Jiang Chuan Tai Cao (阳江川苔草). The epithet yangjiangensis (阳江) refers to Yangjiang City, Guangdong Province, South China, where this new species was found.
Conservation status.
According to our investigation, Cladopus yangjiangensis was only found in a stream in Yangjiang City, Guangdong Province, China, and hence we suggest its placement in the Data Deficient category of IUCN (2022). In addition, according to the Updated List of National Key Protected Wild Plants (Decree No. 15) by the country’s State Forestry and Grassland Administration and the Ministry of Agriculture and Rural Affairs, all of the known genera of Podostemaceae found in China are classified as under national secondary protection. This new species should also be included on the national secondary protection list during the upcoming revision process.
description: Published as part of Zhang, Miao, Liu, Xiu-Ting, Tian, Min, Chen, Zhang-Xue, Huang, Ying-Lin, Chen, Guo-Di & Chen, Bing-Hua, 2024, Cladopus yangjiangensis (Podostemaceae), a new species from Guangdong, South China, redefining the phylogenetic relationships within Cladopus, pp. 231-249 in PhytoKeys 249 on pages 231-249, DOI: 10.3897/phytokeys.249.140342