Vaccinium jiuwanshanense Ying Qin, Yan Liu & Y.H.Tong, sp. nov. (Figs. 1 & 2). Type:— CHINA. Guangxi: Luocheng County, Jiuwanshan National Nature Reserve, Baihe protection station, elev. ca. 514 m, 5 May 2022, Ying Qin & Gao Xie GXQY20220505001 (holotype IBK!; isotypes IBK!, IBSC!). Diagnosis:—The new species is similar to V. subfalcatum Merrill ex Sleumer (1941: 475) in having narrow leaf blades with serrate margins (each serra with one short and black glandular hair at apex), obconical and densely pubescent hypanthium, and tubular-urceolate and pubescent corolla with 5 longitudinal ridges abaxially, but can be easily distinguished from the latter mainly by its 15–80 cm tall (vs. 2–5(–7) m) stem, dense (vs. scattered) leaves with acute (vs. long acute or subfalcate) apexes, pubescent (vs. glabrous or very sparsely pubescent) peduncle and rachis, bracteoles inserted near apex (vs. below middle) of pedicel, corolla with small teeth (vs. without teeth) at middle of longitudinal ridges, and stamens with ca. 0.1 mm long and downward (vs. ca. 0.7 mm long and upward) spurs on the back of anther tubules. Small evergreen shrubs. Stem 15–80 cm tall, (1–)1.5–5(–14) mm in diameter, with many raised and semiccular scars, base swollen, up to 6 cm in diameter, creeping firmly on the surfaces of rocks. Young branches green, pubescent, turning to gray-brown and glabrescent when older. Leaves dense; petiole 1–2 mm long, pubescent; leaf blade narrowly lanceolate, 1.7–3.1 × 0.4–0.7 cm, thinly leathery, cuneate-attenuate at base, acute and with a gland at apex; margin serrate, each serra with one short and black glandular hair at apex, adaxially pubescent and sparsely glandularhispidulous on mid-vein, trichomes becoming sparser or absent distally, abaxially sparsely glandular-hispidulous, with glandular protuberances on mid-vein; mid-vein raised on both surfaces; lateral veins 4–5 pairs, flat and obscure adaxially, slightly raised abaxially. Inflorescence shortly racemose, 1.5–3.3 cm long, pseudo-terminal or axillary, 3–7- flowered; peduncle 3–9.8 mm long, pubescent; rachis 4–15 mm long, pubescent. Bracts ovate, ovate-lanceolate to narrow-lanceolate, 5.8–14.5 × 2–3.9 mm, green or reddish, margin serrate at margin, glabrous or pubescent on midvein on both sides. Pedicel 2.7–4 mm long, pubescent, articulate with hypanthium; bracteoles 2, similar to bracts but smaller, 5.7–9.7 mm × 1.6–2.5 mm, inserted near apex of pedicel. Hypanthium green, obconical, 2.2–2.7 mm tall, 2.5–3.1 mm in diameter, densely pubescent; calyx limb 1.6–1.8 mm tall, divided nearly to base; lobes 5, broadly triangular, 1.3–1.5 mm tall, 1.6–1.9 mm wide, densely pubescent abaxially, glabrous adaxially, margin entire, apex acute. Corolla white, sometimes tinged reddish, rarely reddish, tubular-urceolate, 8.5–11.1 mm long, 4.5–6.5 mm in diameter, pubescent on both surfaces, with 5 longitudinal ridges abaxially, each longitudinal ridge with 1–2(–4) small teeth at middle, rarely teeth inconspicuous, 5-lobed at apex; lobes triangular, reflexed, ca. 1.3 × ca. 1.1 mm, pubescent on both sides, densely papillose adaxially and at the apical and marginal area abaxially, apex acute. Stamens (9–)10, 5.4–7.8 mm long; filaments white, flat, straight, 2.9–4.3 mm long, densely villous and papillose; anthers slightly dimorphic, dark-yellow, 2.5–3.6 mm long, thecae 1.4–1.8 mm long, densely papillose, tubules 1.1–1.8 mm long, with very small spurs at base abaxially, spurs ca. 0.1 mm long, downward. Ovary inferior, pseudo-10-locular. Disc green, annular, densely pubescent. Style green, cylindrical, 7.5–9.3 mm long, densely papillose, very sparsely villous at base; stigma truncate. Berry globose, 4.1–6.7 mm in diameter, densely pubescent outside; fruiting calyx lobes persistent, inflexed, appressed to berry. Phenology: —Flowering in April and May, fruiting in July and August. Etymology: —The epithet is derived from the type locality Jiuwanshan National Nature Reserve, Guangxi, China. Vernacular name:—Aξψηq (Chinese pinyin: jiǔ wàn shān yùe jú). Taxonomic notes:— There are eight species of Vaccinium recorded in Jiuwanshan National Nature Reserve, viz. V. bracteatum Thunberg (1784: 156), V. guangdongense W.P.Fang & Z.H.Pan (1981: 112), V. iteophyllum Hance (1862: 223), V. japonicum Miquel (1863: 28) var. sinicum (Nakai in Nakai & Koidzumi 1922: 168) Rehder (1924: 56), V. longicaudatum Chun ex W.P.Fang & Z.H.Pan (1981: 110), V. mandarinorum Diels (1900: 516), V. supracostatum Handel-Mazzetti (1934: 3), and V. jiuwanshanense. The new species, V. jiuwanshanense, is special and easily distinguished from the other seven species in the reserve by its dense, small and narrow leaves, pubescent corolla with small teeth at middle of longitudinal ridges. Besides, it grows on river banks, while all the other species grow in montane forests or thickets. It is most similar to V. subfalcatum, a species distributed in S Guangxi and SW Guangdong of China, and N Vietnam. A detailed comparison between the two species is provided in Table 1. Distribution and ecology: — Vaccinium jiuwanshanense is only found in Jiuwanshan National Nature Reserve, Guangxi, China. It grows on the surfaces of rocks on river banks with an elevation of ca. 514 m. The new species is companied by Ficus abelii Miq., Macaranga henryi (Pax & K. Hoffm.) Rehder, Adina rubella Hance, Photinia stenophylla Hand. -Mazz., Musa balbisiana Colla, Iris speculatrix Hance, Hemerocallis citrina Baroni, Pogonatherum crinitum (Thunb.) Kunth, Blechnum orientale L., Odontosoria chinensis (L.) J. Sm., Osmunda vachellii Hook., etc. Conservation status: —At present, the new species has been discovered with 31 mature individuals growing along ca. 260 m long bank of the Baotan River. However, the Baotan River is ca. 50 km long, and there are other similar rivers in or near Jiuwanshan National Nature Reserve, such as Niubi River, Lalang River, Liaodong River, etc. Many sections of the Baotan River and banks of these rivers have not yet been investigated. The available data are not enough to evaluate the conservation status of the new species. Thus, according to Guidelines for using the IUCN Red List Categories and Criteria (IUCN Standards and Petitions Committee 2022), Vaccinium jiuwanshanense is assessed as data deficient (DD). Additional specimens examined (paratypes): — CHINA. Guangxi: Luocheng County, Jiuwanshan National Nature Reserve, Baihe protection station, elev. ca. 514 m, 2 August 2021, Ying Qin & Shi-Chang Dai GXQY20210802012 (IBK!); ibid., 1 May 2022, Ying Qin & Gao Xie GXQY20220501005 (IBK!); ibid., 17 May 2022, Ying Qin GXQY20220517001 (IBK!).

Published as part of Qin, Ying, Huang, Yu Song, Tan, Fei, Liu, Yan & Tong, Yi Hua, 2023, Vaccinium jiuwanshanense (Ericaceae), a new species from Guangxi, China, pp. 220-226 in Phytotaxa 591 (3) on pages 220-225, DOI: 10.11646/phytotaxa.591.3.4, http://zenodo.org/record/7800881