Sedum xunvense Y.L. Xu & P. Li

Chai, Mao-Lin, Wu, Ya-Meng, Pu, Yang Zhang Jin-Bao, Chen, Bin, Xu, Yue-Liang & Li, Pan, 2024, Sedum xunvense, a new species from Southeast China, Phytotaxa 644 (4), pp. 258-270 : 263-266

Sedum xunvense Y.L. Xu & P. Li , sp. nov. ( Figs. 3–6 )

Type. China — Zhejiang, Jiangshan City, Jianglang Mountain , under forest by ravine, in mossy thicket, on rock wall, 252m, 1 June 2023, Y ueliang Xu & Pan Li, Xu2864 (holotype: ZM; isotypes: HZU, CSH, PE, KUN) .

Description. Herbs, annual, glabrous. Roots fibrous. Sterile stems absent. Fertile stem solitary, branched proximally, slender. Fertile stems erect, 7–17 cm; stems and inflorescence purplish-red, finely ribbed. Leaves flattened, alternate, withered at anthesis; leaf blade obovate to spatulate, (1.3–1.8) cm × (0.5–0.6) cm, rounded at tip, tapering to a 3–5 mm long pseudopetiole in lower and middle parts, base with short spur. Cymes, numerous-flowered, first stage tridentatebranched, later 2–3-forked-branched; flowers sessile; leaf-like bracts small, spatulate to obovate, (0.3–1.8) cm × (2–5) mm; sepals 5, unequal, spatulate to obovate, (2–4) mm × (0.8–2.8) mm, rounded at the tip, tapered at the base into a pseudopetiole c. 0.5mm long, detached, shortly spurred; petals 5, yellow, lanceolate, (4.5–5) mm × (~1) mm, base ca. 0.5mm connate; stamens 10, antesepalous filaments 3–3.5 mm long, antepetalous filaments 2.5–3 mm long, inserted at petal base ca. 0.5 mm, anthers reddish-brown; nectary scales 5, inverted trapezoidal, yellowish, (~0.25) mm × (~0.3) mm, truncated flat at tip; carpels 5, ovate-lanceolate, ca. 3.2–4 mm, base ca. 0.5 mm connate, stigma ca. 1 mm; ovules 8–13, long ovate terete, slightly compressed, surface densely covered with fine warty projections. Follicles light brown, oblique, 3–3.5 mm long, persistent stigma ca. 1 mm; seeds light brown, ellipsoid, 0.6–0.7 mm long, 0.25–0.3 mm in diameter, abaxially sparsely covered with fine papillate projections.

Distribution and habitat. Sedum xunvense has only been found on Jianglang Mountain, Jiangshan City, in southwestern Zhejiang Province. It grows in mossy thickets on rock walls and under the forest by the ravine at an elevation of 239 meters.

Phenology. Flowering and fruiting period from May to June.

Etymology. The species epithet is named after the Xunv Lake in Jianglang Mountain, where this new species was found.

Vernacular name. xū nǚ jǐng tiān (Chinese pronunciation); NJfffiƙ (Chinese name).

Conservation Status. Sedum xunvense is endemic to Jianglang Mountain, and it is currently known from a single rock by the trail, with less than 100 individuals. It could be easily destroyed or over-harvested. Therefore, S. xunvense should be classified as Critically endangered (CR) according to IUCN criteria B and C [6–8].

Additional specimen examined (paratypes). China - Zhejiang, Hangzhou City, Fuyang district, collected from cultivated individual, elevation ca. 20m, 29 May 2023, Yueliang Xu, Xu2860 (ZM).

Figures

FIGURE 3. Sedum xunvense Y.L. Xu & P. Li, sp. nov. A. Habitat, B. Population, C. Habit, D. Habit (cultivated), E. Habit, F. Root, G. Flower, H. Immature follicle.

FIGURE 4. The holotype of Sedum xunvense Y.L. Xu & P. Li, sp. nov.

FIGURE 5. Sedum xunvense Y.L. Xu & P. Li, sp. nov. A. Habit, B. Stem, C. Flower, D. Petals and stamens, E. Carpels and nectar scales, F. Follicle, G. Sepals.

FIGURE 6. Distribution map of Sedum xunvense (●).