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| Aletris medogensis W.B.Ju, Y.L.Qiu & Bo Xu, in X. Li, Qiu, J.-T. Li, Xu, Yu et Ju, 2026. 墨脱粉条儿菜 || DOI: doi.org/10.1002/ece3.72654 |
ABSTRACT
The genus Aletris L. (Nartheciaceae) encompasses approximately 21–24 species distributed in East Asia and North America, yet taxonomic ambiguity persists due to overlapping morphological traits among closely related species. During fieldwork in southeastern Xizang, China, a morphologically distinct candidate species, Aletris medogensis, was discovered. To validate its taxonomic status and explore evolutionary relationships within East Asian Aletris, we integrated detailed morphological observation with comparative chloroplast phylogenomics. The newly proposed species is characterized by creeping stolons, narrow leaves, and glandular-pubescent inflorescences. Comparative analysis of 14 East Asian Aletris complete chloroplast genomes revealed a conserved quadripartite structure with species-specific variations, including pseudogenization of ycf1, loss of rrn4.5, and shifts in IR boundaries. Phylogenomic analyses strongly supported A. medogensis as a distinct species closely related to A. alpestris. We identified 18 hypervariable regions as potential molecular markers and detected signals of positive selection in genes ccsA, cemA, and rps12, suggesting adaptive evolution. This study confirms the recognition of A. medogensis as a new species endemic to the eastern Himalayas and demonstrates the utility of chloroplast genomics in resolving taxonomic complexity and understanding evolutionary mechanisms in Aletris.
Keywords: Aletris medogensis, comparative chloroplast genome analysis, East Asia, IR boundary dynamics, molecular markers, Nartheciaceae, selective pressure
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| Aletris medogensis. Lateral (a), front (b), and back (c) views of the flower. (d) Stamens. (e) Ovary and stigma. (f) Inflorescence. (g) Scape. (h) Bracteate leaf. (i) Leaf. (k) Roots. (l) Plant. |
Aletris medogensis W.B.Ju, Y.L.Qiu & Bo Xu, sp. nov.
Diagnosis: Aletris medogensis is morphologically most similar to Aletris alpestris, but it can be distinguished from the latter in having narrower leaves (0.45–0.9 mm wide vs. 1–2.5 mm wide) and an obtuse apex (vs. an acuminate apex); the flower pedicels are extremely short, the rachis has densely glandular hairs (vs. sparsely puberulent), the two bracts are unequal in length and shorter than the flowers (vs. one of them 1–4 × flower length). Lobes are obtuse to rounded at the apex (vs. the apex being obtuse to acute).
Etymology: Located in southeastern Xizang Autonomous Region, Medog (Pinyin spelling “motuo”) County is one of the biodiversity hotspots in China, which has rich plant diversity in the Eastern Himalaya (Qiu et al. 2022). The new species, Aletris medogensis, is found in this region and is named after the geographic location. Its Chinese name, mo tuo fen tiao er cai (墨脱粉条儿菜).
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| Habit of Aletris medogensis on moss-covered rocks along streams (photographed by Wen-Bin Ju). |
Xiong Li, Yong-Ling Qiu, Jiang-Tao Li, Bo Xu, Qi Yu and Wen-Bin Ju. 2026. Integrating Morphology and Chloroplast Genomics: A New East Asian Species of Aletris (Nartheciaceae) With Insights Into Regional Phylogeny and Evolution. Ecology and Evolution. DOI: doi.org/10.1002/ece3.72654 [05 January 2026]
