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| Primula xideensis W.B.Ju, Hu Ju & Bo Xu, in J.-T. Li, X. Li, Liu, Xu, Hu, Meng et Ju, 2026. |
Abstract
We document and illustrate Primula xideensis, a new species collected from Xide County, Sichuan Province, China. Morphologically, it resembles P. stenocalyx, P. farinosa s.l., and P. pulchella, but differs by its roots densely covered with multicellular hairs; elliptic to obovate leaves with non-revolute, irregularly and deeply dentate margins, both surfaces efarinose, shortly hairy, and scabrous; tubular calyx parted to the middle; corolla mouth densely white-farinose; stamens positioned at mid-corolla tube in pin flowers and near the throat in thrum flowers; styles reciprocally placed; and an oblong capsule shorter than the persistent calyx. To clarify its phylogenetic placement, we constructed phylogenetic trees using two datasets: 63 complete chloroplast genome sequences and 75 nuclear ribosomal DNA internal transcribed spacer (nrITS) sequences. Both trees showed similar topologies, consistently placing the new species within a monophyletic group of Sect. Aleuritia, supporting its assignment to this section. For a deeper comparison between the new species and other members of Sect. Aleuritia, we incorporated chloroplast genomes of seven additional species from this section. The results revealed highly conserved chloroplast genomes among all eight species, with only minor differences between the new species and the others. Primula xideensis is currently known only from its type locality. Based on IUCN Red List criteria, its conservation status is assessed as Data Deficient (DD).
Keywords: Primula sect. Aleuritia; morphological taxonomy; chloroplast genomics; molecular phylogeny
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| Habitat of Primula xideensis sp. nov. |
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| Primula xideensis sp. nov. (A) fresh plants; (B) plant base, showing the roots and withered old leaves. (C) leaves; (D) Leaf abaxial surface and indumentum; (E) Corolla; (F) Bracts and calyx; (G) pin flower; (H) capsule; (I) seed; (J) thrum flower. |
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| Primula xideensis sp. nov. (A) habit; (B) leaves; (C) Leaf indumentum; (D) Bracts and calyx; (E) flowers: pin flower, thrum flower; (F) front of the flower; (G) capsule. |
Primula xideensis W.B.Ju, Hu Ju, Bo Xu sp. nov.
Diagnosis: Primula xideensis is most similar to P. stenocalyx, P. farinosa s.l. and P. pulchella, but differs by its roots densely covered with multicellular hairs, leaves with dentate to irregularly deeply dentate margins, both surfaces efarinose, densely short-hairy and scabrous, corolla mouth densely white-farinose, pin flowers with stamens inserted about the middle of the corolla tube and styles adjacent to the corolla throat, thrum flowers with stamens positioned near the corolla throat and styles inserted about the middle of the corolla tube, and an oblong capsule shorter than the persistent calyx.
Jiang-Tao Li, Xiong Li, Cheng-Wu Liu, Bo Xu, Jun Hu, Fan-Juan Meng and Wen-Bin Ju. 2026. Primula xideensis (Primulaceae), A New Species from Sichuan, China, Based on Morphological and Molecular Evidence. Plants. 15(12), 1829. DOI: doi.org/10.3390/plants15121829 [12 June 2026]
