Updated description of Diospyrosdussaudii Lecomte (Ebenaceae), with lectotypification and notes on its distribution.

Sutee Duangjai,Kwanjai Khammongkol,Padungsak Suekaew,Aroon Sinbumroong,Wittawat Kiewbang,Porntawat Chalermwong,Somran Suddee,Sukid Rueangruea,Theerawat Thananthaisong

doi:10.3897/phytokeys.184.71045

Abstract

Diospyrosdussaudii is a poorly known species and previous descriptions lacked details about its female flowers and fruits. The species had not been recorded since type collections were made in 1913. As a result of our Diospyros research in Thailand, new specimens and data are now available for this species. In this study, we provide an updated morphological description, illustrations, lectotypification and a distribution map. The species was previously reported to be endemic to Laos; as such, the occurrences in Thailand greatly expand the distribution of the species. In addition, we analysed the phylogenetic relationships between D.dussaudii and other Diospyros species from Southeast Asia and other regions, using DNA sequence data from eight plastid regions. Our phylogenetic analyses indicate that D.dussaudii is closely related to D.castanea, D.dasyphylla and D.insidiosa. Their taxonomic affinities are discussed.

Highlights

The taxonomy of the genus Diospyros L. in Thailand is fairly well documented, some specimens do not fit species in the known flora of Thailand (Phengklai 1981, 2005; Duangjai et al 2018, 2020; Eiadthong 2020)
Based on examination of type specimens at P, we identified a male specimen of the unknown Diospyros from peninsular Thailand as D. dussaudii
After careful study of the protologue and type specimens (Fig. 1), we determined that our collections from peninsular Thailand matched the description and type specimens of D. dussaudii

Summary

Introduction

The taxonomy of the genus Diospyros L. in Thailand is fairly well documented, some specimens do not fit species in the known flora of Thailand (Phengklai 1981, 2005; Duangjai et al 2018, 2020; Eiadthong 2020) This was the case for specimens collected from Phu Langka National Park in Nakhon Phanom Province, north-eastern Thailand in 2013 and from Chumphon Province, peninsular Thailand in 2014. The leaves and buds of these specimens resemble those of D. dasyphylla Kurz, which occurs in Thailand Their fruits are globose or depressed-globose, ca. (Meliaceae), but different from those of D. dasyphylla, which has glabrous fruits When we compared these specimens with species known to occur in Indochina (Lecomte 1928, 1930), as well as specimens from the Muséum national d’Histoire naturelle (P), we observed similarities in the leaves and buds to a poorly known species from Laos, D. dussaudii Lecomte. We could not positively identify the specimens due to lack of detail on the female plants of D. dussaudii in the published descriptions and due to the absence of male specimens amongst our collections

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