Cardamine mangshanensis X. L. Yu, A. Liu & X. Li 2025, sp. nov.

Cardamine mangshanensis X. L. Yu, A. Liu & X. Li sp. nov. Figs 1, 2 Diagnosis. This new species is similar to C. macrophylla Willd., but it differs in the following characteristics: more prominent tubers, shorter plant height (10–25 cm vs. 20–115 cm), fewer cauline leaves (3–4 vs. 3–18), distinctly petiolulate leaflets (vs. sessile or occasionally with a short petiole), crenate leaf margin (vs. serrate), fewer flowers (4–10 vs. 10–30), white flowers (vs. purple or lilac, rarely white), an earlier flowering period (late February to mid-March vs. April to June) and shorter growth cycle in one year (ca. 3 months vs. ca. 8 months) (See Fig. 4, Table 1). Type. China. Hunan: Chenzhou City, Yizhang County, Mt. Mangshan, Hejiawan, in sparse forests within limestone areas, elevation ca. 650 m, 27 February 2021, Ang Liu & You-ke Gong HJW 01 (Holotype CSFI!, isotype CSFI!, HIB! & CSH!) (See Fig. 3). Description. Herbs perennial, delicate, 10–25 cm high. Rhizomes creeping, with tubers, 0.3–5 cm long. Stems erect, unbranched, surface furrowed, smooth. Cauline leaves 3–4, petiole 1.5–5 cm long, smooth, not auriculate at base, margin glandular serrate; terminal leaflets elliptic or oblong, (1.5 -) 2.5–4 (- 5.5) × (0.5 -) 1–2.5 (- 3) cm, sparsely pilose, petiole 0.5–1.5 cm long, base cuneate, margin crenate, rarely doubly serrate, apex acute, slightly caudate; lateral leaflets 2–4 pairs, sparsely pilose, petiole 0.5–2.5 cm long, base obliquely cordate or truncate, margin crenate, equal to or slightly smaller than terminal leaflets. Racemes 4–10 flowered, dense, inflorescence slightly elongated in fruit, pedicel 0.5–1.5 cm long. Sepals elliptic, ca. 0.5 cm long, green, glabrous or very sparsely pilose. Petals white, obovate, 1 cm long, blunt at the top and cuneate at the base. Stamens glabrous, ca. 6 mm long, filaments about 4 mm long, base slightly dilated, anthers purplish red. Pistils 5–7 mm long, ovary columnar, style slender, ca. 3 mm long, equal to or slightly longer than the ovary. Mature fruit not observed. Phenology. Flowering occurs from late February to mid-March. Interestingly, after completing seed propagation (before mid-April), the aboveground parts of the plant wither. Etymology. The specific epithet of this new species is derived from its type locality, Mt. Mangshan, one of the most famous mountains in southern Hunan. Distribution and habitat. This new species is currently known only from the limestone landform area of Mt. Mangshan, where it typically grows beneath sparse bamboo forests. Additional specimens examined (Paratypes). China. Hunan: Chenzhou City, Yizhang County, Mt. Mangshan, Hejiawan, in sparse forests within limestone areas, elevation ca. 650 m, 25 March 2020, Ang Liu & Xiong Li LAHJW 01 (CSFI!, HIB! & CSH!). Conservation status. Currently, only one population with a total of about 300 individuals has been found in the limestone areas of Mt. Mangshan. This population is located within the boundaries of Mangshan National Nature Reserve and is minimally affected by human activities. Based on the IUCN Red List criteria (IUCN 2024), the conservation status of the new species should be better categorized as ‘ Vulnerable, VU B 2 ab (ii) ’.