Stimpsonia danxiacola Xiao L. Zhao, Yan S. Huang & Q. Fan 2026, sp. nov.

Stimpsonia danxiacola Xiao L. Zhao, Yan S. Huang & Q. Fan sp. nov. Figs 1, 2, 3, 4, 5 Type. China • Preserved from a flowering plant cultivated at Sun Yat-sen University, originally collected in Guangxi Zhuang Autonomous Region, Guilin City, Ziyuan County, Mount Bajiaozhai, along a mountain roadside, 26.2946, 110.7068, 583 m a. s. l., 20 January 2026, Li-Juan Liao & Xiao-Lan Zhao GX 24; • flowering material preserved on 7 May 2026, Xiao-Lan Zhao SD 001 (holotype: SYS [SYS 00237147]!). Diagnosis. The new species differs from Stimpsonia chamaedryoides and S. nanlingensis in its perennial habit (vs. annual), densely glandular-pubescent plants with viscid leaves, compound racemiform inflorescences (vs. simple racemiform), long pedicels (0.4–2.6 cm vs. 2.0–8.0 mm and ca. 0.3 mm, respectively), pale pink flowers (vs. white and white or pink), and longer style (ca. 1.2 mm vs. ca. 0.6 mm and 0.3 mm, respectively). It further differs from S. nanlingensis in having calyx lobes that become connivent in fruit (vs. reflexed or patent). Description. Perennial herbs, marked individuals can resprout in successive years in the wild, 22–27 cm tall, densely glandular-pubescent throughout. Stem erect, solitary, occasionally branched, densely glandular-pubescent. Basal leaves petiolate; petioles 2.0– 8.5 cm long, densely glandular-pubescent; blades elliptic to broadly ovate, 2.8–6.0 × 2.1–4.6 cm, green, chartaceous, with deeply cordate bases, densely glandular-pubescent on both surfaces, margins irregularly dentate. Cauline leaves alternate, 0.2–3.0 × 0.2–2.8 cm, densely glandular-pubescent on both surfaces; petioles gradually shortened upward; blades orbicular, with deeply cordate bases, dentate margins, and gradually reduced upward. Flowers axillary, solitary, arranged in a lax, spreading compound-racemiform inflorescence 13–27.6 cm long; primary branches 6.2–15 cm long, secondary branches 1.2–3.9 cm long; whole inflorescence densely glandular-pubescent; pedicels 0.4–2.6 cm long, densely glandular-pubescent. Calyx ca. 2.1 mm long, densely glandular-pubescent, 5 - lobed nearly to the base; lobes reflexed at anthesis, gradually connivent in fruit. Corolla pale pink, ca. 4.8 mm long, 5.0–7.0 mm in diameter; tube ca. 3.0 mm long; lobes 5, obovate, 1.5–2 × 1.6–3 mm, apex emarginate, sometimes irregularly undulate, internally pubescent. Stamens ca. 1 mm long, labrous; anthers basifixed, subovoid, ca. 0.2 mm long, introrse. Ovary superior, ovoid, glabrous. Style ca. 1.2 mm long, persistent and exserted in fruit; stigma capitate. Capsule globose, ca. 3.0 mm in diameter, densely glandular-pubescent, shorter than the persistent calyx, dehiscent along dorsal sutures, valves spreading outwards. Seeds ca. 16 per capsule, depressed-globose, ca. 0.6 mm diam., brownish; testa conspicuously reticulate-foveolate with irregular lumina and slightly raised muri, and with a dark depressed area and a minute protrusion at the center. Phenology. Flowering from April to October; fruiting from May to October. Etymology. The specific epithet refers to the danxia landscape. The Chinese name is “ 丹霞假婆婆纳 (dān xiá jiă pó pó nà) ”. Distribution and habitat. S. danxiacola is currently known from the danxia landscape of Ziyuan County, Guilin City, Guangxi (Fig. 6). Putative additional populations of this species occur in the adjacent Mount Langshan area of Hunan Province, as inferred from specimen records in the Chinese Virtual Herbarium (https://www.cvh.ac.cn/spms/detail.php?id=eee5d835). It grows along mountain roadsides in moist soil at elevations of 300–650 m. Provisional conservation status. The type locality lies near a hiking trail in the Danxia Scenic Area, which is subject to heavy tourism pressure and anthropogenic disturbance. This species is currently known from only a single confirmed locality: Bajiaozhai, Ziyuan County, Guilin City, Guangxi Zhuang Autonomous Region, at an elevation of 583 m, with approximately 40 mature individuals at this site. However, the full distribution range, population size, and habitat preference of this species remain poorly investigated. Considering that it may potentially occur in other underexplored danxia landscape habitats across the region, the currently available data is insufficient to accurately evaluate its conservation status. Following the IUCN Red List Categories and Criteria (IUCN 2001, version 3.1), we therefore propose a provisional conservation classification of Data Deficient (DD) until its actual distribution and population status are comprehensively clarified through further field investigations. Additional specimens examined. Stimpsonia danxiacola: China • Cultivated at Sun Yat-sen University, from living material originally collected in Guangxi Zhuang Autonomous Region, Guilin City, Ziyuan County, Mount Bajiaozhai, along a mountain roadside, 1 January 2026, Li-Juan Liao & Xiao-Lan Zhao GX 25; • fruiting material gathered on 26 May 2026, Xiao-Lan Zhao SD 002 (SYS [SYS 00237148!, SYS 00237149!]). • Hunan: Xinning County, Mount Langshan, under rocks, 300 m a. s. l., Y. B. Luo 2279 (PE). Stimpsonia chamaedryoides: China • Zhejiang Province: Nanping City, Pucheng County, Zhongxin Town, within Jiulongshan National Nature Reserve, alt. 888.39 m, 13 April 2018, Xin Zhong, Shang Qu, Shu-Bo Huang ZX 01647 (CSH); • Jiangxi Province: Zixi County, Matoushan Town, Zhuyan Mountain, 27°48'49"N, 117°13'27"E, 17 Oct 2025, Yan-Shuang Huang JX 16 (SYS!); • Zhejiang Province: Baishanzu, in valley forest, 16 April 2013, Fang-Gang Zhang BSZ 0128 (ZMNH); • Jiangsu Province: Changzhou City, Liyang City, Songling of Liyang, 27 Apr 2007, Q. X. Liu et al., LS- 072, (NAS, NAS 00579254); • Fujian Province: Nanping City, Da'anyuan of Wuyi Mountain, roadside, 21 Jun 2017, S. Z. Liu 3975, (XMBG, XMBG 0010427). Stimpsonia nanlingensis: China • Guangdong Province: Ruyuan Yao Autonomous County, Nanling National Forest Park, 24°55'N, 113°03'E, 650 m a. s. l., 8 May 2016, G. H. Huang 160033 (IBSC!); • Guangdong Province: Ruyuan Yao Autonomous County, Nanling National Forest Park, 24°57'N, 113°03'E, 1153 m a. s. l., 2 Jan 2026, Qiang Fan, RY 23 (SYS!).