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| Metapetrocosmea navicularis F.Wen, T.V.Do, Z.B.Xin & K.Tan, in Li, Tan, Do, Xin, Bai, He et Wen, 2025. Hình dáng giống thuyền || DOI: doi.org/10.3897/phytokeys.261.160454 |
Abstract
Based on morphological comparisons, literature reviews, and molecular systematic studies, a new species from South Vietnam, Metapetrocosmea navicularis F.Wen, T.V.Do, Z.B.Xin & K.Tan, has been confirmed. Morphologically, this new species resembles Metapetrocosmea tamiana (B.L.Burtt) Yin Z.Wang & P.W.Li in leaf peltate, bilabiate corollas, arcuate filaments, and slightly curved capsule, while it is distinguished from M. tamiana in having leaf blade ovate to ovate-elliptic, boat-shaped bracts 6–9 mm long, the ratio of corolla lobes length to corolla tube length consistently 1 : 3, corolla tube gradually narrowed from mouth to base, subcylindrical-infundibulate, 10–20-flowered or more, filaments pubescent near the top. Molecular phylogenetic analyses using the combined dataset of trnL-F and ITS sequences show that the new species is also most closely related to M. tamiana. The conservation status of this new species is assessed as Least Concern (LC).
Key words: Didymocarpoideae, Flora of Vietnam, Metapetrocosmea tamiana, morphology, phylogeny
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| Metapetrocosmea navicularis. A. Habitat; B. Plants; C. Leaves; D. Bracts; E. Frontal view of flower; F. Lateral view of corolla; G. Calyx lobes; H. Stamens; I. Opened corolla showing the interior surface of corolla tube, stamens and staminodes; J. Pistil and disc; K. Fruits; L. Micro-morphological characters of species seeds (Photos A, K were taken by Fang Wen; C, D by Qi-Yang Li and the rest were taken by De-Chang Meng). |
Metapetrocosmea navicularis F.Wen, T.V.Do, Z.B.Xin & K.Tan, sp. nov.
Diagnosis. Metapetrocosmea navicularis is similar to M. tamiana in macroscopic morphology, and phylogenetic analysis indicates that they are the closest relatives (Fig. 1). But it is easy to distinguish the new species from M. tamiana by its leaf blade ovate to ovate-elliptic (vs. cordate to nearly round, the following comparisons follow the same order), leaf densely puberulent adaxial (vs. with mixture of long and short pubescence adaxial), bracts 6–9 mm long (vs. ca. 2 cm long), the ratio of corolla lobes length to corolla tube length consistently 1 : 3 (vs. approximately 1 : 1), 10–20-flowered or more (vs. 4–6-flowered), corolla tube gradually narrowed from mouth to base, subcylindrical-infundibulate (vs. wider in upper part, abruptly contracted towards base, distinctly infundibulate), filaments pubescent near the top (vs. glabrous), style puberulent (vs. pubescent), and stigma arcuate (vs. nutant) (Table 2).
Vernacular name. “Hình dáng giống thuyền” (Understood as the bracts of this species are interpreted as naviculate shape). Its Chinese name is Chuán Bāo Dùn Yè Jù Tái (Chinese pronunciation); 船苞盾叶苣苔.
Qi-Yang Li, Ke Tan, Truong Van Do, Zi-Bing Xin, Xin-Xiang Bai, Song-Tao He and Fang Wen. 2025. Metapetrocosmea navicularis, A New Species of Gesneriaceae in Vietnam. PhytoKeys. 261: 87-98. DOI: doi.org/10.3897/phytokeys.261.160454
