Sedum guangxiense Yan Liu & C. Y. Zou, 2025

Zou, Chun-Yu, Meng, Tao, Meng, Shi-Yong & Liu, Yan, 2025, A new species of Sedum (Crassulaceae, Saxifragineae) from Guangxi, China, PhytoKeys 252, pp. 287-299 : 287-299

Sedum guangxiense Yan Liu & C. Y. Zou sp. nov.

Figs 2 , 3

Type.

China • Guangxi: Fangcheng District, Na-suo Town, top of Nanshan . Elevation, 830 m; 21°44'49"N, 108°6'37"E, 24 April 2021. H. L. Chen ZCY 1978 (holotype: IBK!, isotype: PE!) .

Diagnosis.

Sedum guangxiense is similar to S. tosaense and S. emarginatum in its leaf shape and inflorescence type, but can be distinguished from the latter two by its erect stems in youth (vs. prostrate when young), much larger leaves (1.5–3.5 cm long vs. 1–2 cm), narrowly triangular petals (vs. narrowly elliptic-lanceolate and linear-lanceolate to lanceolate), ovate nectar scales (vs. subquadrangular and oblong) and larger, oblong anthers (rather than oblong-ovoid).

Description.

Biennial herb, fleshy, glabrous. Roots fibrous, with several adventitious roots in the leaf axils of the basal nodes. Stems stout, erect when young, with irregular branching, to 10–25 cm tall. Leaves alternate, base spurred, sessile, thick, spatulate to obovate, 1.5–3.5 cm long, 0.5–1 cm wide, apex usually retuse, rarely round, base long-attenuate. Inflorescences terminal, many flowered cymes, usually with three branches, each 2 - forked; bracts leaf-like, 5–10 mm long, 2–5 mm wide; flowers usually sessile, usually 5 -, sometimes 4 - or 6 - merous; Sepals usually 5, sometimes 4 or 6, free, green, fleshy, strongly unequal in size, spatulate to obovate, 3–8 mm long, 1–3 mm wide, apex usually retuse, rarely round. Petals usually 5, sometimes 4 or 6, yellow, narrowly triangular, 5–6 mm long, 1.1–1.5 mm wide, apex acuminate, slightly connate at base. Stamens usually 10, sometimes 8 or 12, shorter than petals, erect at anthesis, arranged in two whorls; antesepalous ones 3.5–4 mm, antepetalous ones 3–3.5 mm; anthers oblong, ca. 0.8 mm long, reddish-brown before dehiscence. Nectar scales ovate, 0.3–0.4 mm. Carpels usually 5, sometimes 4 or 6, connate at the base for ca. 0.3–0.5 mm, gibbous ventrally, 5–6 mm long; styles 1.6–2 mm long. Fruits star-shaped, many seeded follicles, spreading. Flowering April to May, fruiting May to July.

Distribution and habitat.

The species is known from Bai-shou Town in Yongfu County and Na-suo Town in Fangcheng District, Guangxi, China. It grows on mossy rocks in secondary broadleaf forests at elevations of 200–550 m (Fig. 4 ).

Etymology.

The specific epithet refers to the distribution in Guangxi Province, China.

Additional specimen examined

(paratypes). China • Guangxi: Yongfu County, Bai-shou Town , on mossy rocks along streams, elev. 263 m, 25°11'43.29"N, 110°49'42.89"E, 10 May 2021, C. Y. Zou & J. Q. Huang, ZCY 1977 ( IBK!) ; • Fangcheng District, Na-suo Town, the top of Nanshan , 21°44'49"N, 108°6'37"E, 19 April 2021, Y. G. Liu, Q. G. Yang & H. L. Cheng 1208 ( IBK!) .

Figures

Figure 2. Sedum guangxiense A plant in flower B sterile plant C inflorescence from below D flowering branch E strongly unequal sepals F side view of a flower with carpels removed, showing the sepals, petals, stamens and nectar scales G adaxial leaf surface H unripe follicles I carpels connate at the base in longitudinal section J ovules K abaxial leaf surface. A, photographed by Hai-ling Chen in Fangcheng District (corresponding to the holotype H. L. Chen ZCY 1978); B, C, photographed by Chun-Yu Zou in Yongfu County (corresponding to the paratype C. Y. Zou & J. Q. Huang, ZCY 1977).

Figure 3. Holotype of Sedum guangxiense, H. L. Chen ZCY 1978 (IBK).

Figure 4. Distribution of Sedum guangxiense Yan Liu & C. Y. Zou (pentagram stars) in Guangxi, China. The red pentagram star indicates the locality of the holotype (type locality).