Sinosenecio yaanensis K. Huang & Z. X. Fu 2025, sp. nov.

Sinosenecio yaanensis K. Huang & Z. X. Fu sp. nov. Figs 1, 2, 3 Type. China • Sichuan Province, Ya’an City, Tianquan County, Xingye Township, 29°52'36.89"N, 102°45'14.70"E, elev. 1,500–1,600 m, growing in humid forest understory with shade, 29 April 2025 (fl.), Ke Huang & Zhixi Fu 8550 (holotype: SCNU!) (Fig. 3). Diagnosis. Sinosenecio yaanensis resembles S. chienii and S. homogyniphyllus in being scapigerous herbs with solitary, erect stems and palmately veined ovate to ovate-cordate radical leaves, but differs by its subcoriaceous blades with marginal whitish blotches adaxially and purplish red abaxially, densely fulvous-villous petioles, 3–10 capitula with about 8 ray florets bearing the longest ligules (11–12 mm), and achenes lacking a pappus (Table 1). Description. Scapigerous perennial herbs. Rhizomes short and stout, 1.5–3.5 mm in diam., with numerous fibrous roots. Stem solitary, erect, scapiform, 16–24 cm tall, simple, pale brown, sparsely pilose with white hairs. Leaves several, radical, rosulate, densely fulvous villous as the stems, long petiolate, petioles 6–12 cm long; blade ovate or ovate-cordate, with marginal whitish blotches, 4.5–9 × 4–8.5 cm, subcoriaceous; adaxially green, densely white-pubescent, especially along veins; abaxially purplish red, sparsely pubescent, with reddish-brown hairs on veins; margin villous; palmately veined, lateral veins 3–5 pairs, base cordate, margin entire with slight serration, apex acute. Capitula 3–10, 2–3 cm in diameter, arranged in a terminal corymb; peduncles slender, 3–8 cm long, green to pale brown, minutely and sparsely puberulent, with several linear bracts subtending the corymb. Receptacle slightly raised and pubescent. Involucres campanulate, 6–8 × 3–4 mm, ecalyculate; phyllaries 8–10, lanceolate, 6–7.5 × 1.5–2 mm; herbaceous, sparsely puberulent outside; green, apically purplish, acuminate. Ray florets ca. 8; corolla tube 1.3–2.3 mm long, glabrous; rays yellow, oblong, 11–12 × 3–4 mm, 4 - veined, apically 3 - denticulate. Disc florets numerous; corolla yellow, 4–5 mm long, with ca. 2–3 mm tube and campanulate limb; lobes ovate-oblong, ca. 1 mm long, apically acute. Anthers oblong, ca. 2 mm long, basally obtuse. Style branches ca. 0.5 mm long, recurved, apically truncate. Achenes cylindric, 2.4–3 mm long, smooth, glabrous. Pappus absent. Floral micromorphological characters. The filament collar of S. yaanensis consisted of uniformly sized cells (Fig. 2 I), and the anther endothecial cell wall thickenings were strictly polarized (Fig. 2 J). Phenology. Flowering from April to May; fruiting from May to June. Etymology. The specific epithet is derived from the type locality, Ya’an City, Sichuan Province, China. The proposed Chinese name is “ 雅安蒲儿根 ”, pronounced as “ yǎ ān pú ér gēn ”. Distribution and ecology. The new species is currently known only from its type locality, i. e. Tianquan county, Ya’an city in western Sichuan, China (Fig. 4). It grows in the humid, shaded forest understory at an altitude of 1,500–1,600 m above sea level. Conservation status. Sinosenecio yaanensis is currently recorded only from Tianquan County, Ya’an City, Sichuan Province, China. Field investigations revealed an estimated population of approximately 400–500 mature individuals confined to a narrow distribution range. According to the IUCN Red List Categories and Criteria (IUCN 2024), this meets the criteria for Vulnerable (VU) status under criterion D 1, which applies to taxa with fewer than 1,000 mature individuals.