Rhododendron mingii (Ericaceae), a new species from Southeast of Yunnan, China Author Liu, Zhenwen 0000-0001-9397-2260 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China & Yunnan Academy of Forestry and Grassland, Kunming, China & Gaoligong Mountain, Forest Ecosystem, Observation and Research Station of Yunnan Province, Yunnan, China & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Yunnan, China & liuzw @ mail. kib. ac. cn; https: // orcid. org / 0000 - 0001 - 9397 - 2260 liuzw@mail.kib.ac.cn Author Liu, Ende 0000-0003-4424-9820 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China & liuende @ mail. kib. ac. cn; https: // orcid. org / 0000 - 0003 - 4424 - 9820 liuende@mail.kib.ac.cn Author He, Deming 0009-0005-9070-5235 The Management Bureau of Wenshan National Nature Reserve, Wenshan, China & tobming @ 126. com; https: // orcid. org / 0009 - 0005 - 9070 - 5235 tobming@126.com Author Ma, Yongpeng 0000-0002-7725-3677 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China & Lijiang Forest Biodiversity National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Lijiang 674100, Yunnan, China & mayongpeng @ mail. kib. ac. cn; https: // orcid. org / 0000 - 0002 - 7725 - 3677 mayongpeng@mail.kib.ac.cn Author Gao, Lianming 0000-0001-9047-2658 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China & Lijiang Forest Biodiversity National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Lijiang 674100, Yunnan, China & gaolm @ mail. kib. ac. cn; https: // orcid. org / 0000 - 0001 - 9047 - 2658 gaolm@mail.kib.ac.cn text Phytotaxa 2023 2023-10-05 619 1 97 104 http://dx.doi.org/10.11646/phytotaxa.619.1.5 journal article 10.11646/phytotaxa.619.1.5 1179-3163 8425798 Rhododendron mingii Y.P. Ma, L.M. Gao & E.D. Liu , sp. nov. ( Figure. 1 ) The new species resembles R. genestierianum by flower shape and petal color, but differs from the latter by the much shorter petiole and leaf, densely white powder on outer surface of petal, and slender and erect style ( Table 1 ). Type:— CHINA . Yunnan : Wenshan Prefecture , Maguan County , Laojun Mountain , ca. 2500 m , 14 May 2019 , E.D. Liu , Y. Yang & Y.Y. Li , OYY00214 ( holotype : KUN !) . TABLE 1. Comparison of Rhododendron mingii and R. genesterianum
Characters R. mingii R. genestierianum
Leaves Clustered at stem apex Alternate
Petiole 2–3 mm 8–15 mm
Leaf blade length 4–6 cm 6–15 cm
Leaf margin Leaf scales Sparse hairs Scales 6–8 × their own diameter apart Glabrous Scales 2–4 × their own diameter apart
Style Slender and erect Stout and sharply deflexed
Distribution range NW Yunnan, SE Tibet SE Yunnan
Shrubs, evergreen, 1–2 m tall; stem and branches glabrous, gray white, bark peeling. Petiole grooved, 2–3 mm long; leaves clustered at stem apex, leathery, oblong-lanceolate, 3–6(8) × 1–2 cm , base cuneate, apex caudate-acuminate, margin slightly revolute and fringed with sparse hairs; abaxial surface pale green, densely white powder, scales sparse, small, circular, about equal in size, brown; adaxial surface green, shiny; midrib grooved adaxially; lateral veins 10–12- paired, usually not obviously reaching the margin. Inflorescence terminal, umbellate, 5–9-flowered. Pedicel 1–1.5 cm , glabrous, white powder; calyx pruinose, rim-like, slightly lobed, 2–3 mm long, persistent; corolla campanulate, fleshy, pruinose, reddish purple, 1.2–1.6 cm long, tube 0.8–1.2 cm long, glabrous; stamens 10, unequal, 0.5–1.5 cm long, shorter than style, filaments glabrous, unequal, 0.4–1.2 cm long, anthers ca. 2 mm long, deep red; ovary scaly; style purple, 1.2–1.5 cm long, glabrous, slender and longer than corolla; stigma small, capitate. Fruit not known. FIGURE 1. Rhododendron mingii A. Flowing branch. B. Close-up view of leaf blade abaxial surface. C. Gynoecium. D. Stamens. E. Opened corolla. F. Habit. (A–E drawn by Y. Luo from the holotype). FIGURE 2. Maximum Likelihood tree based on the concatenate sequences of the three DNA barcodes ( rbcL , matK and ITS) under the General Time Reversible model. Bootstrap values (>50%) are shown along the clades. TABLE 2. Variable nucleotide sites of rbc L and ITS in the examined samples. A dot (.) indicates the same character state as the first sequence.
Species Position rbc L 71 155 238 251 273 381 530 ITS 148 193 216 247 423 462 493 520 541
R. mingii sp. nov A G T A C G C C A A C T C C T G
R. hanceanum 1 • • • • T • • • • G • C • • • A
R. hanceanum 2 • • • • T • • • • G • C • • • A
R. longistylum • • • • • T • • • G T C • • • A
R. baihuaense 1 • • • • • • • • • G • C • T • •
R. baihuaense 2 • • • • • • • • • G • C • T • •
R. genestierianum B444 • • • • • • • • • G • C T • C •
R. genestierianum B445 • • • • • • • • • G • C Y • C •
R. tephropeplum 2 G C A G • • T T • G • C • • • A
R. tephropeplum 1 G • A G • • • • G G • C • • C •
R. xanthostephanum B691 G • A G • • • • R G • C • • C •
R. xanthostephanum B692 G • A G • • • • G G • C • • C •
R. xanthostephanum B693 G • A G • • • • G G • C • • C •
TABLE 3. Variable nucleotide sites of mat K in the examined samples. A dot (.) indicates the same character state as the first sequence, ‘_’ indicates an alignment gap.
Species Position mat K 39 67 74 80 88 123 126 244 250 251 252 258 278 496 569 620 637 664 669
R. mingii sp.nov G C G G C T T A T A G A G C G A T T G
R. hanceanum 1 • • • T • • • • • • • • • • • • C • •
R. hanceanum 2 • • • T • • • • • • • • • • • • C • •
R. longistylum • • • T • • • • • • • • • • T • • • •
R. baihuaense 1 • • • T • • • • • • • • • • • • • • •
R. baihuaense 2 • • • T • • • • • • • • • • • • • • •
R. genestierianum B444 • • • T • • • • • • • • • • • • • • •
R. genestierianum B445 • • • T • • • • • • • • • • • • • • •
R. tephropeplum 2 C T T T T T C T _ _ _ G A T • C • C •
R. tephropeplum 1 C • T T A T C T _ _ _ G A T • C • • C
R. xanthostephanum B691 C • T T A T C T _ _ _ G A T • C • • C
R. xanthostephanum B692 C • T T A T C T _ _ _ G A T • C • • C
R. xanthostephanum B693 C • T T A T C T _ _ _ G A T • C • • C
Distribution and ecology :—To date, Rhododendron mingii has only been found from the type locality of Laojun Mountain, Malipo County, SE Yunnan of China ( 104°34’E , 22°57’N ). It grows in evergreen bushes on the summit of Laojun Mountain at an elevation of ca. 2500 m , co-occurring with R. maguanense Feng (1983: 268) and R. sinofalconeri Balfour (1916: 272) . Phenology :— Rhododendron mingii flowers from April to May. Etymology :—The specific epithet is in honor of Prof. Tien-Lu Ming, a taxonomist of the genus Rhododendron . Notes: —Base on morphological and phylogenetic evidence in the present study, we are still unable to make an accurate subsectional placement for the new species, due to no clear boundaries between subsections Tephropepal and Genestieriana ( Figure 2 ). Morphologically, R. mingii is similar to R. genestierianum , but the most contrasting character distinguishing them is the characteristic of style ( Table 1 ). In general, whether a slender or deflexed style is the key trait to define subsections in section Rhododendron . However, there is exception for the subsection Moupinensia , which is including three species and R. moupinense Franchet (1886: 33) has slender style whereas the remaining two have deflexed styles. The newly discovered R. mingii would further raise the interesting topic regarding the importance of style characteristics in defining subsection or species within section Rhododendron .