Lanonia yunnanensis R. P. Kuang et J. W. Qin, sp. nov. (Fig. 1–3)

Type:— CHINA. Yunnan, Wenshan Zhuang and Miao Autonomous Prefecture, Maguan County, Gulinqing Township, limestone mountain forest, 22.700°N, 103.970°E, 681m, 04 May 2024, Jia -Wei Qin & Ren -Ping Kuang ZC050302 (holotype: ♀, HNNU!); ibidem, 22.731°N, 103.995°E, 564m, 04 May 2024, Jia -Wei Qin & Ren -Ping Kuang ZC050401 (paratype: ♂, HNNU!).

Description:— Plants shrubby, evergreen, and dioecious, up to 2 m tall. Stems 37(14–55) cm long, 4.2(1.8–5.8) cm diameter, clustered. Leaves 9(5–17) per stem; ligules 10.2(6.0–16.0) cm long, soon disintegrating into fibers; sheaths and proximalmost part of petioles with scattered, brown scales; petioles 107.3(25.0–147.0) cm long, 1.0(0.7– 1.3) cm wide at the apex; petiole thorns usually stout, some bifid or in pairs, reddish-brown or dark brown, more or less regularly arranged on proximalmost part of petiole; hastulas raised, triangular, infolded; leaf blades 59.7(18.0–85.0) cm long, 70.2(20.0–95.0) cm wide; costas 50.3(42.5–55.0) cm long, 1.1(0.5–1.5) cm wide, narrow, continuous to apex of leaf, without an abaxial pulvinus; segments 5 or 7 per leaf in majority, mottled or not mottled, with minute, reddish-brown scales abaxially, with (on dried specimens) straight margins; middle segments 49.1(20.0–73.0) cm long, 47.5(10.0–67.0) cm wide at the apex (the middle segment width given above represents the total middle segment width, not half); apices of middle segments with adaxial splits not much deeper than abaxial ones. Inflorescences 34.9(27.0– 43.0) cm long; prophylls 7.3(4.0–11.0) cm long; peduncles 9.6(2.0–22.0) cm long; rachis bracts flattened, strongly ribbed, splitting apically and laterally and tattering along the ribs; rachillae slender and ribbed, densely covered with much branched, brownish-white hairs; staminate rachises 26.5(19.0–37.0) cm long; staminate partial inflorescences 2–3, branched to 2–4 orders; staminate rachillae 6(3–12), 17.1(14.0–21.5) cm long, 0.6(0.4–0.8) mm diameter; staminate flowers 2.0(1.5–2.1) mm long; sepals not pedicellate at the base, densely hairy; petals with a narrowed apex, solid internally; stamens with alternately long and short filaments and small, almost square anthers; filaments not elongate; pistillodes undivided; pistillate rachises absent or 28.5(20.0–37.0) cm long; pistillate partial inflorescences 1–2, branched to 1–2 orders; pistillate rachillae on proximalmost partial inflorescence 2(1–3), 17.6(11.0–25.0) cm long, 1.0(0.5–1.2) mm diameter; pistillate flowers 3.6(3.1–4.1) mm long; fruits size and shape not recorded, reddish; seeds 8(7–9) mm diameter, globose, with a curved basal intrusion.

Distribution and habit: Southwestern China, specifically in Maguan County and Hekou County, the China-Vietnam border areas of Yunnan Province, in tropical seasonal rainforests on limestone soils at elevations ranging from 149 m to 673 m (Fig. 4).

Phenology: Flowering April to May, fruiting October to November.

Etymology: The specific epithet "yunnanensis " is a Latinized adjective derived from the Chinese pinyin "Yún Nán" ("云南" in Chinese characters), referring to its distribution within Yunnan Province of China.

Additional specimens examined: CHINA. Yunnan, Honghe Hani and Yi Autonomous Prefecture, Hekou County, Nanxi Township, in the understorey of forest, 22°40′11.1″N, 103°56′13.8″E, 149m, 08 May 2012, Yu-Min Shui, Zhi-Yong Yu, Jiang-Hai He, Zhi-Guo Yang, Bo Ding, Xiang-Yu Tian & Huai-Chun Li 94653 (KUN).

Taxonomic notes: Lanonia yunnanensis is notable for its undivided middle segment that is significantly wider than lateral ones, and costa continuous to the apex of the leaf, without an abaxial pulvinus, a unique combination of characters shared exclusively with L. manglaensis (Henderson, Ninh & Nguyen) Henderson & Nguyen (2017: 165) within the genus.