Allium brevipedicellatum Xiao W. Li & Bo Yang sp. nov. (Figs 1–3). Type:— CHINA. Helan Mountain of Inner Mongolia, arid hillside, 38.501 2972, 106.130 9824, 2429 m of elevation, 18 July 2025, Shi Wenjie NMGHLS-250718124 (holotype: PE, isotypes: PE; Figure 2). Diagnosis:— Allium brevipedicellatum can be distinguished from its two similar species, Allium bidentatum Fisch. ex Prokhanov (1929: 83) and Allium tenuissimum Linnaeus (1753: 301) by the presence of a creeping rhizome, with the outer bulb tunics membranous and yellowish-brown; the very short pedicels of only 1–2 mm long and the purplish-red perianth segments (Table 2) (Flora of China Editorial Committee, 1980). Perennial herb with rhizomes, cylindrical bulbs 3–5 mm in diameter, slender and clustered; outer tunics thin, yellowish-brown, splitting into fibers. Leaves narrowly linear, semicylindrical, solid, grooved adaxially, 0.5–1 mm wide, up to 10 cm long, shorter than the scape; scape with longitudinal ridges, cylindrical, erect, 10–25 cm long, 1 mm in diameter, lower part covered by leaf sheaths. Spathe unilaterally split or bifid, membranous, persistent. Inflorescence hemispherical, small, 1–1.5 cm in diameter, compact with 5–15 (rarely more) flowers; pedicels nearly equal in length, very short to subsessile, 1–2 mm long. Flowers purplish-red. Tepals 6 in two whorls; outer tepals oblong, apex acuminate, 4–5 mm long, 2–3 mm wide; inner tepals oblong-ovate, apex obtuse, 5–6 mm long, 3–4 mm wide. Filaments white, nearly equal in length, slightly shorter than tepals; inner filaments with basal portion dilated into an ovate shape (about 1/2–2/3 of filament length), without teeth; anthers elliptical, purplish-gray or purple. Ovary subglobose, base with concave nectariferous pit, 2 ovules per locule. Style longer than ovary, not exserted beyond perianth. Capsule and seeds not studied. Phenology: —flowering and fruiting from June to September. Etymology: —The species epithet derives from the pedicels of this species which are 1–2 mm long, significantly shorter than those of other Allium plants. Vernacular name: —The Chinese name is ‘ ñDz¨’ (duǎn gěng jiǔ). Distribution and habitat: — Allium brevipedicellatum is distributed in areas at an elevation of 2200 to 2700 meters on the eastern slope of Helan Mountain, including Huangqigou, Ruqigou and Suyukougou (Ningxia Hui Autonomous Region), and on the western slope, including Halawugou and Nansigou (Inner Mongolia Autonomous Region) (Fig. 4). Its typical habitats include stony slopes, rock crevices of mountain ridges, shrubbery and grassland communities. Furthermore, the Flora of Inner Mongolia states that the species under discussion is also distributed in Langshan and Zhuozishan of the Inner Mongolia Autonomous Region, as well as in the Qilian Mountains (Gansu Province and Qinghai Province) (Zhao et al. 2020). Discussion: —In the course of our review of the pertinent literature, we observed that The Flora of Helan Mountains described Allium brevipedicellatum as Allium kansuense (Zhu et al. 2012). However, both “Flora Reipublicae Popularis Sinicae” and “Flora of China ” treat A. kansuense as a synonym of A. sikkimense (Flora of China Editorial Committee 1980, Wu & Raven 2000). A thorough examination of the original description of A. kansuense reveals that it is distinguished by its leaves, which measure 2–5 mm in width. The scape apex is characterized by a curved configuration, and the flowers exhibit a vibrant blue hue, with tepals that measure 6–8 mm in length. The filaments are also blue in colour (Regel 1889). These traits are consistent with those of A. sikkimense, thereby providing a rationale for the proposed merger. In contrast, the specimen under scrutiny exhibited markedly divergent morphological characteristics, including leaves measuring approximately 1 mm in width, an erect scape, purple-red flowers with tepals measuring 4–5 mm in length, and white filaments. These distinctions deviate markedly from the description of A. kansuense and differ from all currently known Allium species (Table 1). In terms of species distribution, A. sikkimense grow on mountain slopes, in grasslands and at the edges of forests, as well as under shrubs, at elevations between 2.400 and 5.000 meters. They prefer relatively moist environments. Allium brevipedicellatum is found in areas with elevations between 2.200 and 2.700 meters. It typically grows on rocky slopes and in the crevices of mountain ridges in relatively arid conditions. It is evident from the analysis of field measurements and the description in The Flora of Helan Mountains that this taxon warrants recognition as a distinct species. This conclusion necessitates its reclassification and formal description. During the literature review, it was found that Fu's dissertation mentioned this species and used the name " Allium sessiliflorus " (Fu 2023). According to Article 30.9 of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN), this name does not constitute valid publication as the formal description process has not yet been completed. Therefore, a formal redescription of this species is provided herein. The Helan Mountains and the adjacent eastern Alxa–western Ordos region form one of China's eight major biodiversity centers, representing the core of the Alxa-Ordos Biodiversity Hotspot. This area is of particular ecological significance due to its status as one of only two such centers in northern China and the sole one in the arid northwest. Floristic surveys in the Helan Mountains are of pivotal importance in order to unravel the origin and evolution of the Alxa desert flora and to reconstruct the environmental history of the Central Asian arid belt (Li et al. 2012). The discovery of this species is significant as it enhances our understanding of the biodiversity of Allium and has the potential to provide insights into the evolutionary history of the genus. The study of this subject may provide critical insights into the complex ecological relationships that exist among sympatric plant species in the Helan Mountains. This would serve to further emphasize the scientific importance of the region.

Published as part of Yang, Bo, Wang, Wenqiang, Dai, Rui, Xu, Hao, Hao, Shuxiang, Fan, Yuke, Liang, Yongliang & Li, Xiaowei, 2025, Allium brevipedicellatum (Amaryllidaceae), a new species from the Helan Mountains in China, pp. 91-98 in Phytotaxa 732 (1) on pages 93-95, DOI: 10.11646/phytotaxa.732.1.9, http://zenodo.org/record/18423282