Carex liboensis X. J. Zhao & X. F. Jin 2026, sp. nov.

3.Carex liboensisX. J. Zhao & X. F. Jin sp. nov. Figs 2 K, 2 L, 3 F – J Diagnosis. This new species is similar to Carex austrosinensis Tang & F. T. Wang ex S. Yun Liang in having central culms, leaf-like bracts and brown-green utricles but differs by lateral spikes rather densely flowered, base with peduncles enclosed in bract sheaths, nutlets with three angles shallowly constricted at middle. Type. China • Guizhou: Libo Xian, Shishang Forest Scenic Area; 25.273400, 107.895980; on limestone under forest; 22 March 2024; X. J. Zhao 2024032201 (holotype: ZJFC; isotype: ZM). Description. Herbs perennial. Rhizomes short, woody, stiff. Culms central, densely caespitose, 20–40 cm tall, trigonous, scabrous, base with brown or yellow-brown fibrous sheath. Leaves longer than culms, sometimes nearly equal in length; blades flat, nearly leathery, 1–1.5 mm wide, scabrous on both surfaces and margins. Bracts leaf-like, longer than spikes, lowest far longer than others, base sheathing; sheaths 4–20 mm long. Spikes four, racemose, remote; terminal spike staminate, thinly cylindrical, 2–3 cm long, 1–1.5 mm wide, densely flowered, base with a slender peduncle; lateral spikes androgynous, cylindrical, 2–3.2 cm long, 3.5–4 mm wide, staminate part 0.5–2 cm long, pistillate part 1–2 cm long, base with peduncles enclosed in sheaths. Staminate glumes obovate, brown, laterally pale brown, 3.5–4 mm long, apex acute, with 1 - veined dark brown costa dorsally. Pistillate glumes broadly ovate, pale brown, ca. 3 mm long, apex mucronate, with 1 - veined dark brown costa dorsally. Utricles brown-green, obovoid (beak excluded), obtusely trigonous, 5–5.5 mm long, longer than pistillate glumes, distinctly thinly veined, glabrous, base attenuate, apex gradually contracted into a ca. 1 mm long beak, orifice 2 - lobed with short teeth. Nutlets tightly enveloped, castaneous, rhombic-ovoid, trigonous, ca. 2 mm long, with three angles shallowly constricted at middle, sides slightly concave below, base with a short and curved stipe, apex abruptly contracted into a short, coiled beak; style base thickened; stigmas three. Etymology. The specific epithet “ liboensis ” refers to the type locality of this new species in Libo County of Guizhou Province. Phenology. Flowering and fruiting occur in late March. Conservation status. The new species is currently known only from the type locality. As surveys and collections at the type locality and in surrounding areas have been limited, its full geographic range, population size and trends, and potential threats remain insufficiently documented. Consequently, the available information is insufficient to determine whether the species meets any of the IUCN criteria for a threatened category. The species is therefore provisionally assessed as Data Deficient (DD) following the IUCN Red List Categories and Criteria (IUCN 2024). Notes. With its rhombic-ovoid nutlets and brown-green utricles (5–5.5 mm long), the new species is similar to Carex austrosinensis Tang & F. T. Wang ex S. Yun Liang. It differs from the latter in having rather densely flowered lateral spikes, peduncles enclosed in bract sheaths at the base, and nutlets shallowly constricted at the middle angles. In contrast, Carex austrosinensis possesses sparsely flowered lateral spikes, peduncles long-exserted from bract sheaths, and nutlets that are not constricted at the middle.