Taxonomic Studies on Malagasy Dalbergia (Fabaceae). III. Two New Species from Southeastern Madagascar and an Emended Description of the Rosewood Species Dalbergia maritima

Abstract

Abstract— The Malagasy rosewood species Dalbergia maritima has a long history of unsustainable exploitation for its beautiful, burgundy-colored heartwood. As currently circumscribed, D. maritima has a wide geographic distribution in eastern Madagascar and exhibits significant morphological, ecological, and genetic variation, suggesting it may comprise more than a single entity. Multivariate analyses of leaf, flower, and inflorescence characters as well as eco-geographic features reveal several morphologically well delimited entities with distinct habitat preferences and/or geographic ranges, which are consistent with results from recent phylogenomic and population genomic studies of Malagasy Dalbergia. Based on these findings, we describe and illustrate two new species from southeastern Madagascar comprising material previously assigned to D. maritima, viz. D. pseudomaritima, characterized by paniculate inflorescences and small, broadly elliptic to orbicular, glabrous leaflets, and D. razakamalalae, distinguished by racemose inflorescences with large flowers, and narrowly ovate to narrowly elliptic, glabrous leaflets. Dalbergia maritima is consequently re-circumscribed to include only populations from east-central Madagascar, within which we recognize two subspecies, D. maritima subsp. maritima, with glabrous leaves, inflorescence axes, and gynoecia, occurring in littoral forest habitats, and D. maritima subsp. pubescens, with indument on these structures, and growing in evergreen humid forest farther inland. Photos are provided for each taxon, along with line drawings for the two new species. Provisional IUCN Red List assessments indicate that all three species are Endangered, D. maritima and D. razakamalalae mainly because of selective logging for trade in their high-quality heartwood, and D. pseudomaritima primarily because of habitat degradation due to land clearing and fire for subsistence agriculture, which has important implications for their conservation and sustainable management.

A DNA barcode reference library for CITES listed Malagasy Dalbergia species

“…The recent studies performed on Malagasy members of this genus concur with our phylogenetic analyses in that supergroup 1 includes D. tricolor, D. chapelieri, D. pervillei, D. maritima, and D. normandii and supergroup 2 comprises D. monticola, D. peltieri, D. trichocarpa, D. bemarivensis, D. chlorocarpa, D. lemurica, and D. baronii (Crameri, 2020). Our results are consistent with and complementary to previous studies by Crameri (2020) andHassold et al (2016) regarding the phylogenetic position of the 12 species analyzed herein.…”

“…Our phylogenetic trees can also be used for differentiating species with ITS and in combination with rbcL . Our analyses confirm that the species of Malagasy Dalbergia are divided into two distinct groups (Crameri, 2020; Hassold et al, 2016; Vatanparast et al, 2013). The recent studies performed on Malagasy members of this genus concur with our phylogenetic analyses in that supergroup 1 includes D. tricolor , D. chapelieri , D. pervillei , D. maritima , and D. normandii and supergroup 2 comprises D. monticola , D. peltieri , D. trichocarpa , D. bemarivensis , D. chlorocarpa , D. lemurica , and D. baronii (Crameri, 2020).…”

“…et al (2013) on the phylogeny of Dalbergia indicate that the Malagasy species are divided into three clades, which also include the various African species. This aspect was confirmed byHassold et al (2016) andCrameri (2020) who concluded that, the two identified Malagasy clades diverge from African, American, and Asian Dalbergia, and the island was the subject of at least two independent colonization TA B L E 2…”

Characterization of the chloroplast genome of Dalbergia latifolia (Fabaceae) and its phylogenetic relationship with other Dalbergia species

“…The use of morphological keys for identification of Dalbergia species is challenging due to co‐occurrence of large numbers of closely related species leading to taxonomic uncertainties which has resulted in several revisions of genus (Crameri et al 2022). Ambiguity in species identification can have significant implications in National and International trade regulations and hamper strategizing conservation priorities.…”

Taxonomic Studies on Malagasy Dalbergia (Fabaceae). IV. A New Species from Central and Southern Madagascar and a Narrowed Circumscription for D. emirnensis

“…International de mand has been primarily for rosewood (Mason et al, 2016), whereas in Madagascar, palisander has mostly served the needs of the local market (Rasamoelina, 2001). The taxonomic identity of the Dalbergia species that have been most heavily exploited in Madagascar is largely unknown (Mason et al, 2016), although the highest quality rosewood reportedly comes from the east ern part of the island (Normand, 1988;Ratsimbazafy et al, 2016;Crameri et al, 2022a) and notably from the southern half of the Masoala Peninsula, where precious woods were exploited extensively in the 1960s (Schuur man & Lowry, 2009). Minimum quantitative estimates (Ratsimbazafy et al, 2016) indicated that 152,437 tons of rosewood (corresponding to about 350,430 trees) were harvested in the period between 1991 and 2014, of which 104,655 tons (ca.…”