Homostylium argyropholium Z. X. Fu. A. Habit 2025, comb. nov.

2.Homostylium argyropholium(Hand. - Mazz.) Z. X. Fu comb. nov. Figs 4, 5 ≡ Aster argyropholis Hand. - Mazz., Acta Horti Gothob. 12: 208. 1938. ≡ Sinosidus argyropholis (Hand. - Mazz.) G. L. Nesom, Phytoneuron 2020-64: 13. 2020. Type: China, Sichuan, Kangding (Tatien-lu), frutex fere metralis in declivo aprico, 2 Jul 1922, H. Smith 2258 (holotype, UPS, v- 080214!) (Suppl. material 1: fig. S 25). Type. China • Sichuan, Kangding (Tatien-lu), frutex fere metralis in declivo aprico, 2 Jul 1922, H. Smith 2258 (holotype, UPS, v- 080214!) (Suppl. material 1: fig. S 25). Description. Shrubs, 93–228 cm tall. Leaves subleathery, alternate, elliptic, oblong, or lanceolate-ovate, 1–4 × 0.3–1.6 cm; midvein abaxially prominent, lateral veins apparent, pinnate; margin subundulate to entire, revolute, glandular-punctate, upper leaves smaller; adaxially green, moderately scabridulous, minutely glandular, resin-dotted, scabrous; abaxially densely lanate or greyish-white arachnoid-tomentose. Capitula 4–10 (- 20), with 15–20 ray florets, in corymbiform synflorescences, terminal on axillary branches. Peduncles slender, 2–7 mm, bracteoles linear. Involucres campanulate, ca. 5 mm long, 8 mm in diameter. Phyllaries 4–5 seriate, imbricate, pubescent to glabrescent, outer phyllaries oblong, 1 × 0.5 mm, inner phyllaries ovate, 4–5 × 1 mm. Distribution. China, S and W Sichuan, SE Xizang, NW Yunnan (Fig. 5). Habitat. Alpine and subalpine slopes, under forests, grasslands, riverbanks. 2100–3100 m. Phenology. Flowering May to October. Fruiting August to October. Etymology. It is derived from the Greek “ argyros ”, meaning “ silver ”, and “ pholis ”, meaning “ skin ” or “ scale ”, combined with the Latin neuter suffix “ - um ”. The specific epithet likely refers to the silvery, scale-like, glandular punctate on the leaves. Notes. This species is similar to Homostylium albescens var. discolor. However, it can be distinguished by its fewer capitula borne at the branch tips, narrower involucre, and white buds in the leaf axils. H. polium bears soft and white arachnoid-tomentose on the abaxial leaves, particularly resembling H. argyropholium. However, it has much smaller leaves, and inflorescences borne on lateral branches, allowing for easy differentiation from H. argyropholium.