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| Raphiocarpus taygiangensis C.H.Nguyen, K.S.Nguyen & Aver., in Nguyen, Phung, Nguyen, Averyanov, Truong, ... et Pham, 2023. |
Abstract
Raphiocarpus taygiangensis, a new species of Gesneriaceae family discovered in Tay Giang District, Quang Nam Province, Central Vietnam, is here described and illustrated. The new species is diagnosed by the combination of its stem up to 2 m long, sericeous hairs on young stem, leaf petiole and adaxial mid-vein, sparsely and minutely serrate leaf margin, axillary inflorescence spreading along stem, sparsely long gland-tipped hairs on peduncle, pedicel, calyx, outside corolla and pistil, calyx 5-disparted from base, purplish white flower with purple stripes inside corolla tube, and dish-shaped stigma formed by 2 semi-orbicular lobes horizontally expanding. Distinct features of the new species and its morphologically closest congener, Rhaphiocarpus axillaris, are compared and discussed. The conservation status of the described species is estimated as Vulnerable (VU D2) according to the IUCN Red List Criteria.
Keywords: endemism, flora of eastern Indochina, new taxon, plant diversity, plant taxonomy
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| Raphiocarpus taygiangensis C.H.Nguyen, K.S.Nguyen & Aver., sp. nov. A natural habitat B–D flowering plant in natural habitat E leaves F leaf margin G inflorescences H flowers, views from different sides I flower, frontal views J sagittal section of corolla showing inner surface with stamens and staminodes K flower tube inside and outside L, M stamens N staminode O calyx lobes P pistil, base of pistil and its apex with stigma Q young fruit. Photos by Cuong Huu Nguyen and Khang Sinh Nguyen, correction and design by Cuong Huu Nguyen. |
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| Raphiocarpus taygiangensis C.H.Nguyen, K.S.Nguyen & Aver., sp. nov. A flower front view B habitat C lateral view of flower and fruit; Raphiocarpus axillaris D.J.Middleton, D flower front view E habitat F lateral view of flower and fruit. Photos by Ly Van Nguyen (D–F), Cuong Huu Nguyen and Khang Sinh Nguyen, correction and design by Cuong Huu Nguyen. |
Raphiocarpus taygiangensis C.H.Nguyen, K.S.Nguyen & Aver., sp. nov.
Diagnosis: The new species differs from closest R. axillaris in serrulate leaves, purple spots and glandular hairs on abaxial surface of corolla, purple longitudinal stripes on median lobe of lower lip, and pubescent filaments stamens and pistil (Table 1).
Etymology: The species epithet refers to the name of the district of the type location (Tay Giang District in Quang Nam Province).
Cuong Huu Nguyen, Khoa Van Phung, Khang Sinh Nguyen, Leonid V. Averyanov, Vuong Ba Truong, Chu Van Tran, Hai Xuan Cao, Quan Ngoc Chu, Hau Bich Thi Vu and Thoa Kim Thi Pham. 2023. Raphiocarpus taygiangensis (Gesneriaceae), A New Species from central Vietnam. PhytoKeys. 218: 19-27. DOI: 10.3897/phytokeys.218.96511
