Wednesday, March 14, 2018

[Botany • 2018] Didymocarpus puhoatensis • A New Species (Gesneriaceae) from Vietnam


Didymocarpus puhoatensis X.Hong & F.Wen

in Hong, Li, Maciejewski, Wen & Do. 2018. 

Abstract
Didymocarpus puhoatensis, a new species from Vietnam is described and illustrated with photographs. The new species is morphologically similar to D. brevicalyx and D. epithemoides, but can be easily distinguished by a combination of characters. So far, five species have been recorded in the genus Didymocarpus from Vietnam.

Keywords: Didymocarpus, Gesneriaceae, plant taxonomy, Vietnam



Figure 1. Didymocarpus puhoatensis X.Hong & F.Wen
A Habitat B Adaxial surface view of leaf blade C Adaxial surface view of leaf blade D Cyme with flowers, showing the bracts E Lateral view of corolla, showing the calyx consisting of a tube. 

Figure 2. Flower of Didymocarpus puhoatensis X.Hong & F.Wen
 A–B Frontal view of corolla, showing the disc-like stigma C Top view of corolla D Upward view of corolla E Opened corolla, showing stamens and staminodes F Pistils without corolla.

Didymocarpus puhoatensis X.Hong & F.Wen, sp. nov.

Diagnosis: Although it is morphologically similar to D. brevicalyx, it differs by stem densely pubescent, orbicular purple bracts, apices of calyx lobes obtuse, filaments glabrous, staminodes 2; and also similar to D. epithemoides, but differs from the latter in having purple calyx, funnel-form corolla, 4–5 cm long, glabrous, dark purple-blackish, ovary glandular puberulent.

Etymology: The specific epithet is derived from the type locality, Pu Hoat Nature Reserve, Nghệ An Province, Vietnam.

Distribution and habitat: This new taxon is an endemic species from Pu Hoat Nature Reserve of Vietnam. The species grows on limestone rocks in tropical monsoon forest with sufficient seasonal run-off water, at an elevation of 390 m a.s.l. It distributes much lower in altitude and the habitat is much hotter and more humid than other species with stems of the genus.


 Xin Hong, Zhen-Long Li, Stephen Maciejewski, Fang Wen and Truong Van Do. 2018. Didymocarpus puhoatensis (Gesneriaceae), A New Species from Vietnam. In: Jin X-H, Shui Y-M, Tan Y-H, Kang M (Eds) Plant Diversity in Southeast Asia. PhytoKeys. 94; 87-93.  DOI: 10.3897/phytokeys.94.21650