Accepted Manuscript Phylogeny, biogeography and character evolution in the tribe Desmodieae (Fabaceae: Papilionoideae), with special emphasis on the New Caledonian endemic genera Florian Jabbour, Myriam Gaudeul, Josie Lambourdière, Guillaume Ramstein, Alexandre Hassanin, Jean-Noël Labat, Corinne Sarthou PII: DOI: Reference: S1055-7903(17)30402-5 https://doi.org/10.1016/j.ympev.2017.09.017 YMPEV 5927 To appear in: Molecular Phylogenetics and Evolution Received Date: Revised Date: Accepted Date: 31 May 2017 21 September 2017 22 September 2017 Please cite this article as: Jabbour, F., Gaudeul, M., Lambourdière, J., Ramstein, G., Hassanin, A., Labat, J-N., Sarthou, C., Phylogeny, biogeography and character evolution in the tribe Desmodieae (Fabaceae: Papilionoideae), with special emphasis on the New Caledonian endemic genera, Molecular Phylogenetics and Evolution (2017), doi: https://doi.org/10.1016/j.ympev.2017.09.017 This is a PDF file of an unedited manuscript that has been accepted for publication. 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Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Phylogeny, biogeography and character evolution in the tribe Desmodieae (Fabaceae: Papilionoideae), with special emphasis on the New Caledonian endemic genera Florian Jabboura, Myriam Gaudeula, Josie Lambourdièreb, Guillaume Ramsteina, Alexandre Hassanina, Jean-Noël Labata,, Corinne Sarthoua,* a Muséum national d’Histoire naturelle, Institut de Systématique, Évolution, Biodiversité, UMR 7205 ISYEB MNHN/CNRS/UPMC/EPHE, Sorbonne Universités, 57 rue Cuvier, CP 39, 75005 Paris, France b Muséum national d’Histoire naturelle, Service de Systématique Moléculaire, UMS CNRS 2700, CP 26, 75005 Paris, France  Deceased author. * Corresponding author. E-mail address: corinne.sarthou@mnhn.fr (C. Sarthou). ABSTRACT The nearly cosmopolitan tribe Desmodieae (Fabaceae) includes many important genera for medicine and forage. However, the phylogenetic relationships among the infratribal groups circumscribed using morphological traits are still poorly known. In this study, we used chloroplast (rbcL, psbA-trnH) and nuclear (ITS-1) DNA sequences to investigate the molecular phylogeny and historical biogeography of Desmodieae, and infer ancestral states for several vegetative and reproductive traits. Three groups, corresponding to the Desmodium, Lespedeza, and Phyllodium groups sensu Ohashi were retrieved in the phylogenetic analyses. Conflicts in the topologies inferred from the chloroplast and nuclear datasets were detected. For instance, the Lespedeza clade was sister to the groups Phyllodium+Desmodium based on chloroplast DNA, but nested within the Desmodium group based on ITS-1. Moreover, the New Caledonian endemic genera Arthroclianthus and Nephrodesmus were not monophyletic but together formed a clade, which also included Hanslia and Ohwia based on chloroplast DNA. The hypothetical common ancestor of Desmodieae was dated to the Middle Oligocene (ca. 28.3 Ma) and was likely an Asian shrub or tree producing indehiscent loments. Several colonization events towards Oceania, America, and Africa occurred (all less than ca. 17.5 Ma), most probably through long distance dispersal. The fruits of Desmodieae repeatedly evolved from indehiscence to dehiscence. We also showed that indehiscent loments allow for more variability in the number of seeds per fruit than indehiscent legumes. Modularity seems here to allow variability in the number of ovules produced in a single ovary. Keywords: Arthroclianthus, Desmodieae, Loment, Long distance dispersal, Nephrodesmus, New Caledonia. 1. Introduction The tribe Desmodieae (Benth.) Hutchinson is an Old World tribe of the legume subfamily Papilionoideae. It includes many important genera used for medicine and forage. The tribe Desmodieae comprises 32 genera and ca. 530 species that mostly inhabit tropical, subtropical, and warm-temperate regions, but also extend into the cool-temperate and sub-boreal regions of Eastern Asia and North America (Ohashi, 2005; Ohashi and Ohashi, 2012a; 2012b). Two genera, Arthroclianthus Baill. and Nephrodesmus Schindl., are endemic to New Caledonia. The Desmodieae are commonly erect and trifoliate herbs, shrubs or rarely trees, with fruits either composed of a single article (a legume) or of several segments (a loment; Ohashi et al., 1981) (Fig. 1). The loment consists of a single carpel that disarticulates into single-seeded segments when ripe (Spjut, 1994). Fruit characters are of high taxonomical value in Desmodieae and in Papilionoideae as a whole (e.g. segmentation, dehiscence, size, pubescence, isthmus margin in loments; Kirkbride et al., 2003). The Desmodieae have been once considered similar to tribe Phaseoleae (Polhill, 1981). They were subsequently shown to be a monophyletic group included within Phaseoleae sensu lato, and closely related to subtribe Kennediinae (Doyle and Doyle, 1993; Bruneau et al., 1995; Kajita et al., 1996; Doyle et al., 1997; Wojciechowski et al., 2004; Egan et al., 2016). A supertree using chloroplast DNA data (cpDNA; rbcL, matK, trnL intron; Lewis et al., 2005) placed the Desmodieae in the Millettioid/Phaseoloid clade, the single clade of the Papilionoideae subfamily characterized by a macromorphological apomorphy, pseudoracemose inflorescences (Wojciechowski et al., 2004). The phylogenies published by the Legume Phylogeny Working Group (LPWG, 2013, 2017) showed that the Desmodieae tribe is included within the Indigoferoid/Millettioid clade, together with Phaseoleae sensu lato, Psoraleeae, Abreae, and Indigofereae. Within the phaseoloid Fabaceae, The Desmodieae tribe was strongly supported as monophyletic (for seven of the eight cpDNA markers used; Stefanović et al., 2009), and was sister to Mucuna Adans. Based on morphological traits, Ohashi et al. (1981) defined three subtribes within the Desmodieae: the Bryinae, the Desmodiinae, and the Lespedezinae. Subsequent molecular analyses placed the Bryinae within the Pterocarpus clade of the Dalbergieae sensu lato (Bailey et al. 1997; Doyle et al. 2000; Lavin et al. 2001). Also, the genera Phyllacium Benn. and Neocollettia Hemsl. were moved from the subtribe Lespedezinae to the tribe Phaseoleae based on morphological, palynological, and molecular evidences (Bailey and Doyle, 1997; Doyle et al, 2000, Kajita et al. 2001). Two subtribes are now recognized within the Desmodieae: the Desmodiinae and Lespedezinae (Ohashi, 2005). The subtribe Desmodiinae shows a higher generic diversity in tropical South and South-East Asia (Dy Phon et al., 1994), while the centres of diversity of subtribe Lespedezinae are in temperate East Asia (Huang et al., 2010) and North America (Isely, 1998). The tribe was further circumscribed into three groups based on an analysis of the chloroplast gene rbcL (Kajita et al., 2001; Ohashi, 2005): the Lespedeza group (three genera) corresponding to the Lespedezinae subtribe, and the Phyllodium (12 genera) and Desmodium (17 genera) groups, together corresponding to the Desmodiinae subtribe (Table 1). The Lespedezinae subtribe has been extensively studied during the last decade. Phylogenetic analyses based on cpDNA regions (Kajita et al., 2001; Stefanović et al., 2009; Nemoto et al., 2010) and nuclear ribosomal ITS (Han et al., 2010) strongly supported the monophyly of the Lespedezinae subtribe, including the three genera Lespedeza Michx., Campylotropis Bunge, and Kummerowia Schindl. Campylotropis appeared as the sister group of Kummerowia and Lespedeza. Asia was inferred as the ancestral distribution of the subtribe (Han et al., 2010; Nemoto et al., 2010), and the disjunct distribution of Lespedeza, with eastern Asian and eastern North American species, would be the result of migration through the Bering land bridge during the Miocene (Xu et al., 2012). Later diversification and introgression may have yielded the present species diversity (Xu et al., 2012). Our aim was to provide a robust phylogeny of the tribe Desmodieae using combined chloroplast (rbcL, psbA-trnH) and nuclear (ITS-1) sequence data with a large genera sampling including the previously unanalysed genera Hanslia Schindl. and Leptodesmia (Benth) Benth. We also examined ancestral distribution areas and ancestral states for the habit, fruit type and number of seeds per fruit. Special emphasis was placed on the New Caledonian endemic genera Arthroclianthus and Nephrodesmus, for which a substantial sampling was available. Our results were used to: (1) verify the monophyly of the subtribe Lespedezinae; (2) assess the monophyly of the subtribe Desmodiinae and of each of the two groups defined by Ohashi (2005) within the Desmodiinae; (3) interpret ancestral distribution areas and ancestral states for the habit, fruit type and number of seeds per fruit; (4) specify the phylogenetic relationships of the two endemic New Caledonian genera Arthroclianthus and Nephrodesmus within Desmodiinae; and (5) date their origin in New Caledonia. 2. Materials and Methods 2.1. Taxonomic sampling The sampling included 25 genera out of the 32 recognized in the tribe (Ohashi, 2005; generic sampling ratio = 78%; Table 1). We investigated a total of 58 species of Desmodieae and four outgroup species listed in Table 2. The outgroup species were chosen based on Queiroz et al. (2015): the genera Vigna Savi and Phaseolus L. belong to the Phaseolinae, while Muellera L.f. and Fordia Hemsl. belong to the core Millettieae. Leaf material was either silica-dried in the field, in New Caledonia (for some species of Arthroclianthus and Nephrodesmus), or sampled from herbarium specimens preserved at the Paris Herbarium (Muséum national d’Histoire naturelle; code P). Taxa sampled, voucher information, and GenBank accession numbers are listed in Table 2. 2.2. DNA sequencing We analyzed the nuclear ribosomal ITS-1 and two chloroplast regions (rbcL and psbA-trnH), because these have been used successfully for phylogenetic studies of closely related plants (Shaw et al., 2005), and also for phylogenetic studies within Fabaceae and especially within Papilionoideae (Käss and Wink, 1997; Hu et al., 2002; Han et al., 2010; Nemoto et al., 2010). The chloroplast gene rbcL has been especially used to circumscribe the groups and genera within the Desmodieae tribe (Kajita et al., 2001). Herbarium or silica-dried leaf material was grounded into powder and total genomic DNA was extracted using the Qiagen DNeasy Plant Mini Kit (Valencia, California, USA). PCR amplifications of the two cpDNA markers (rbcL, psbA-trnH) and of the nuclear marker ITS-1 were prepared in 20 µl including 1 µl of non diluted genomic DNA, 2 µl of 10x Taq buffer (with 1.5 µM of MgCl2), 1 µl of dimethyl sulfoxide 2% (DMSO), 1 µl of bovine serum albumine (BSA), 0.8 µl of dNTPs (6.6 mM), 0.32 µl of each forward and reverse primers, 0.6 U Taq polymerase (Qiagen), and sterile distilled water. The following primers were used: rbcL1F (5’-ATGTCACCACAAACAGAAAC-3’) and rbcL724R (5’-TCGCATGTACCTGCAGTAGC-3’) for rbcL (Fay et al., 1997); psbA (5’GTTATGCATGAACGTAATGCTC-3’) and trnHGUG (5’CGCGCATGGTGGATTCACAATCC-3’) for psbA-trnHGUG (Sang et al. 1997; Tate and Simpson, 2003); ITS1 (5’-TCCGTAGGTGAACCTGCGG-3’) and ITS2 (5’GCTGCGTTCTTCATCGATGC-3’) for the nuclear maker ITS-1 (White et al, 1990). The PCR programs consisted of 35 cycles of 1 min of denaturation at 94°C, 1 min annealing at 53°C for rbcL, 56°C for psbA-trnH and 58°C for ITS-1, 2 min extension at 72°C and 10 min final extension at 72°C. PCR amplifications were performed in a Thermal cycler Biometra. The resulting PCR products were then checked on a 1% agarose gel with ethidium bromide. The PCR products were sequenced using Sanger sequencing on a 3730xl DNA Analyzer at Genoscope (Centre National de Séquençage, Evry, France). Forward and reverse sequences were visually edited and assembled using Sequencher v4.9 (Gene Codes Corp., Ann Arbor, Michigan, USA). All newly generated sequences were deposited in GenBank (Table 2). 2.3. Phylogenetic analyses Sequences were automatically aligned in MUSCLE v3.6 (Edgar, 2004) before the alignment was manually revised in BioEdit v.7.2.5 (Hall, 1999). Indels were coded using the simple coding method of Simmons and Ochoterena (2000) in SeqState (Müller, 2005). Both Bayesian inferences (BI) and Maximum Likelihood (ML) analyses were used to estimate phylogenetic relationships. Bayesian inferences were performed using MrBayes v.3.2.5 (Ronquist et al., 2011). For each region, the most adequate model of nucleotide substitution was identified under the Akaike information criterion in MrModelTest v.2.3 (Nylander, 2004): GTR+I+G for ITS-1 and rbcL, and GTR+G for psbA-trnH. For indels, we used the restriction site (binary) model with the option lset coding = variable. Two independent but parallel analyses were conducted using flat priors, starting from random trees and consisting of four chains each. The analyses were run for 5 million generations, sampling every 100 generations and with a 10% burnin. Analysis of output parameters, in Tracer v.1.6 (Rambaut et al., 2014), confirmed the convergence of chains and adequate burnin length. Post-burnin trees were pooled and 50% majority-rule consensus trees were computed with posterior probability (PP) estimates for all nodes. We ran separate analyses for each region, checked that there was no conflict between the topologies based on the two cpDNA regions, and concatenated the rbcL and psbA-trnH sequences to infer a single topology based on the combined cpDNA dataset. Comparison of the combined cpDNA tree with the nuclear ITS-1 tree, however, revealed supported contradictions (with PP > 0.8 and bootstrap support (BS) > 70%); both datasets were hence not combined. The ML analyses were performed in raxmlGUI 1.5.1 (Silvestro and Michalak, 2012; Stamatakis, 2014), using the same partitions and models of nucleotide evolution as for the BI. We performed 1000 rapid bootstrap replicates and searched for the best-scoring ML tree. 2.4. Molecular dating We implemented an uncorrelated lognormal relaxed clock approach in BEAST v.1.8.1 (Drummond et al., 2012), based on the combined cpDNA dataset. The prior for the ucld.mean parameter was uniform between 0 and 10E100, with an initial value of 1. A Birth-Death process was employed as tree prior, and other parameters were left to default values. Node calibration relied on one fossil and one secondary calibration point. A fossil of a Campylotropis species most similar to the extant C. macrocarpa (Bunge) Rehder was dated to 5.3 Ma (Guo and Zhou, 1992; Xu et al., 2012). We therefore modelled the stem node of C. macrocarpa by a uniform prior between 5.3 and 53.0 Ma. In addition, the crown node of tribe Desmodieae was dated to ca. 27.0 Ma by Simon et al. (2009). Therefore, we modelled the age of the tribe by a normal distribution with a mean of 27.0 and a standard deviation of 2.0 Ma. Two Markov Chain Monte Carlo (MCMC) analyses were run for 50 million generations, and sampled every 2000 generations. Tracer v.1.6 was used to confirm convergence among chains and adequate effective sample sizes (ESS > 200). Both chains were combined using LogCombiner 1.4.8, after discarding the first 10% generations as burnin. Trees were summarized in a maximum clade credibility tree obtained in TreeAnnotator 1.4.8, and visualized in FigTree 1.1.2 (available at <http://tree.bio.ed.ac.uk/software/figtree/>). 2.5. Biogeography and character evolution The distribution areas and character states of the extant species were coded according to Ohashi (1973), Kirkbride et al. (2003) and Lewis et al. (2005). We used a DispersalExtinction-Cladogenesis model (DEC; Ree and Smith, 2008) implemented in RASP v.3.2 (Yu et al., 2015) to infer ancestral biogeographical areas. Distribution ranges of extant taxa were coded as combinations of four geographic areas: (a) Asia; (b) Oceania; (c) Africa; (d) America. The condensed tree was the maximum clade credibility tree estimated in BEAST, and the maximum number of ancestral areas was not constrained. To infer the ancestral states for the morphological traits, we used maximum likelihood as implemented in Mesquite v.3.11 (Maddison and Maddison, 2016). Analyses were carried out on the Bayesian cpDNA tree (with 61 tips, after collapsing the branches leading to the two accessions of Ougeinia dalbergioides Benth.), taking into account branch lengths and using the Markov k-state one-parameter model, which is a generalization of the Jukes-Cantor model (Lewis, 2001) and assumes a single rate for all transitions between character states. The habit was coded using five states (including two combined states), namely: (1) Herb (Fig. 1A); (2) Subshrub (Fig. 1B); (3) Shrub (Fig. 1C) or tree (Fig. 1D); (4) Herb and subshrub; (5) Subshrub and shrub or tree. We defined three categories of fruit types: (1) Indehiscent loment (Fig. 1E-F, 1J-M); (2) Dehiscent legume (Fig. 1G-I); (3) Indehiscent legume (Fig. 1N). The size of the fruit characterized by the number of seeds in the fruit was coded using three states: (1) small fruit with up to 3 seeds; (2) average-sized fruit with up to 6 seeds; (3) long fruit with up to 7 seeds and more. For the species producing loments, this character corresponds to the number of articles. For this last character, personal observations (CS) on herbarium specimens were included in the matrix in order to decrease the number of missing data. The matrix of four characters coded for 61 species (including four outgroup species) is presented in Table 2. For comparison, we used parsimony in Mesquite to infer the ancestral states for the phenotypic traits (habit, fruit type, and number of seeds in the fruit). 3. Results 3.1. Phylogenetic relationships In total, our analyses included 62 species and 180 DNA sequences were newly generated. The ITS-1 alignment was 381-position long and included 100 coded indels, whereas the combined cpDNA alignment was 1444-position long (676 for rbcL and 768 for psbA-trnH) with 117 indels coded. Topologies of trees obtained from the BI and ML analyses were similar, only differing for groups with low support values. We hence showed the BS values on the tree topology obtained with the BI (Figs. 2 & 3). Based on the BI using the combined cpDNA dataset, we showed that the tribe Desmodieae is monophyletic (although moderately supported, PP = 0.83; Fig. 2), but there was a trichotomy including the two groups of Desmodieae and the Phaseoleae tribe based on ML. Within the tribe, three clades were identified. First, the clade whose crown node is noted D (PP = 1, BS = 96%; Fig. 2) partly corresponded to the Phyllodium group and included the genera Arthroclianthus Baill., Nephrodesmus Schindl., Hanslia Schindl., Ohwia H. Ohashi, Phyllodium Desv., Dendrolobium (Wight & Arn.) Benth., Droogmansia De Wild., Akschindlium H. Ohashi, Tadehagi H. Ohashi, and Aphyllodium (DC.) Gagnep. Second, the clade whose crown node is noted C (PP = 1, BS = 91%; Fig. 2) corresponded to the Desmodium group and was composed of Desmodium Desv., Hegnera Schindl., Uraria Desv., Christia Moench, Mecopus Benn., Codariocalyx Hassk., Leptodesmia (Benth.) Benth., Alysicarpus Neck. ex Desv., Melliniella Harms, Pseudarthria Wight & Arn., and Hylodesmum H. Ohashi & R.R. Mill. The genus Ougeinia Benth. in Miquel (belonging to the Phyllodium group) was sister to the Desmodium group but with very low support (PP = 0.52, BS = 36%; Fig. 2). Third, the group whose crown node is noted H (PP = 1, BS = 100%; Fig. 2) corresponded to the Lespedeza group. It was the earliest diverging of the tribe and included the genera Campylotropis, Kummerowia, and Lespedeza. Clade D was sister to the Desmodium group+Ougeinia, all together being sister to the Lespedeza group. In our sampling, twelve genera were represented by several species, and four of them were nonmonophyletic: Arthroclianthus, Nephrodesmus, Desmodium, and Alysicarpus (Uraria and Lespedeza were also possibly paraphyletic, but the associated support values were low; PP = 0.76, BS = 20% and PP = 0.77, BS = 68%, respectively). In particular, Arthroclianthus and Nephrodesmus species were intermingled in the phylogeny, and formed a highly supported clade with Hanslia and Ohwia (PP = 1, BS = 87%). Based on ITS-1, the monophyly of the tribe Desmodieae was strongly supported (PP = 1, BS = 100%; Fig. 3). The Phyllodium group was composed of four lineages, two of which included in the basal trichotomy of the tribe: one consisted of Tadehagi and the other of Akschindlium and Droogmansia (PP = 1, BS = 99%; Fig. 3). The third lineage was the genus Ougeinia, and the fourth clustered most genera of the group with PP = 0.76 and BS = 51%. Ougeinia, the main part of the Phyllodium group and all the remaining genera of Desmodieae formed an unresolved and poorly supported clade (PP = 0.64, BS = 32%). The Desmodium group was paraphyletic since the genus Hylodesmum was sister to the Lespedeza group (PP = 1, BS = 84%) and Hylodesmum+the Lespedeza group was sister to the remaining genera of the Desmodium group (PP = 0.90, BS = 57%). Last, the Lespedeza group was retrieved with high support (PP = 1, BS = 96%). Considering the three groups Phyllodium, Desmodium, and Lespedeza, there was one supported conflict between the cpDNA and ITS-1 topologies involving the position of the Lespedeza group. It was retrieved as basal to the tribe and sister group to the groups Phyllodium+Desmodium based on cpDNA, but nested within the Desmodium group and most closely related to genus Hylodesmum based on ITS-1. Within each group, the relationships were similar based on cpDNA and ITS-1, albeit with a few exceptions: i) in the cpDNA phylogeny, Phyllodium and Dendrolobium were grouped (PP = 1, BS = 100%) and Phyllodium+Dendrolobium was sister to Arthroclianthus+Nephrodesmus+ Hanslia+Ohwia with PP = 0.98 and BS = 82% whereas in the ITS-1 phylogeny, Dendrolobium was included in the Arthroclianthus+Nephrodesmus+Hanslia+Ohwia+Dendrolobium clade with PP = 0.95 and BS = 75%. ii) Arthroclianthus and Nephrodesmus formed a supported clade based on ITS-1 (PP = 0.99, BS = 82%), whereas they were grouped with Hanslia and Ohwia based on cpDNA (PP = 1, BS = 87%) because of the position of Nephrodesmus francii (Harms) Schindl. clustering with Hanslia and Ohwia (PP = 0.97, BS = 80%). Also, the respective nonmonophyly of Arthroclianthus and Nephrodesmus relied on a moderate support value in the ITS-1 phylogeny (PP = 0.86, BS = 63%) whereas it was more supported in the cpDNA phylogeny (since N. sericeus Schindl. was sister to several Arthroclianthus species with PP = 1 and BS = 98%). Last, the relationships among Arthroclianthus and Nephrodesmus samples differed between the cpDNA and ITS-1 topologies, e.g., A. angustifolius Hochr., A. balansae Schindl., and A. macrobotryosus Hochr. were grouped with PP = 1 and BS = 82% based on the cpDNA, whereas A. deplanchei Hochr. appeared more closely related to A. angustifolius and A. balansae than A. macrobotryosus based on ITS-1. iii) Alysicarpus was monophyletic based on ITS-1 (PP = 0.99, BS = 100%) whereas it was paraphyletic based on cpDNA, but it must be noted that this paraphyly relied on a moderate support value in the cpDNA topology (PP = 0.84, BS = 55%). iv) Hegnera and Desmodium heterocarpon (L.) DC.+D. heterophyllum (Willd.) DC. were grouped based on cpDNA (PP = 0.95, BS = 51%), but not based on ITS-1. 3.2. Molecular dating Our molecular estimations suggest that the tribe Desmodieae started to diversify 28.3 Ma (95% CI 24.5–32.1 Ma; Fig. 4, crown node A), and that the Phyllodium, Desmodium, and Lespedeza groups started to diversify 20.5 Ma (15.0–25.6 Ma), 17.5 Ma (12.7–22.4 Ma; crown node C), and 14.8 Ma (9.7–20.2 Ma; crown node H), respectively. The clade comprising Arthroclianthus, Nephrodesmus, Ohwia and Hanslia (crown node F) diverged from Phyllodium and Dendrolobium (crown node G) 10.7 Ma (6.6–15.0 Ma) and started to diversify 7.3 Ma (4.3–10.6 Ma). 3.3. Ancestral distribution areas The hypothetical ancestor of Desmodieae (crown node A) and of each of the Desmodium (crown node C), Phyllodium excluding Ougeinia (crown node D), and Lespedeza (crown node H) groups most likely occurred in Asia (with probabilities of 1, 0.69, 1, and 0.73, respectively; Fig. 5). The Lespedeza clade hosts a single colonization event, from Asia to America, which occurred later than 14.8 Ma and led to the Kummerowia and Lespedeza lineage. In the Phyllodium group, Oceania was probably colonized between ca. 10.7 (node E) and 7.3 Ma (node F), since the most likely ancestral areas were Asia at node E (probability of 0.82) and Asia+Oceania at node F (1), giving rise to the Arthroclianthus, Nephrodesmus, Ohwia and Hanslia lineage. Oceania was colonized three additional times, later than 15.4, 10.5, and 1.0 Ma in the lineages leading to Aphyllodium biarticulatum (L.) Gagnep., Tadehagi triquetrum (L.) H. Ohashi, and Phyllodium pulchellum (L.) Desv., respectively. The group Phyllodium also hosts a single colonization from Asia to Africa between 10.5 and 7.7 Ma. Within the Desmodium group, the low resolution did not allow inferring a detailed biogeographic scenario, but the results suggested that America was colonized once, giving rise to the Desmodium intortum (Mill.) Urb. and D. adscendens (Sw.) DC. lineage, and that Oceania and Africa were colonized several times. 3.4. Ancestral states for the habit, fruit type and number of seeds per fruit The hypothetical ancestor of Desmodieae (crown node A; Fig. 6) was most likely a shrub or a tree (probability of 0.52). In the Lespedeza group (crown node H), the most probable ancestral state was the ‘shrub or tree’ state (0.51). All Campylotropis retained this ancestral state, while plant size decreased in the genus Lespedeza, and even more in its sister genus Kummerowia (herb). In the Phyllodium group excluding Ougeinia (crown node D), starting from a most likely ‘shrub or tree’ state (0.84), a few and slight decreases in plant size (from ‘shrub or tree’ to ‘subshrub or ‘shrub or tree’’) were inferred in the lineages leading to N. francii and Ohwia caudata (Thunb.) H. Ohashi, to Droogmansia pteropus (Baker) De Wild. and Tadehagi triquetrum (L.) H. Ohashi, and to Aphyllodium biarticulatum (L.) Gagnep. The ancestor of the Desmodium group (crown node C) was most likely herbaceous (0.49). Several transitions to higher plant sizes (subshrub) occurred in this group. Among these transitions, the state ‘subshrub or ‘shrub or tree’’ evolved at least once and perhaps twice, in the lineage(s) leading to Desmodium velutinum (Willd.) DC. and Codariocalyx gyroides (Roxb.) Hassk. Ancestral state reconstructions using the parsimony criterion provided similar results (result not shown). The hypothetical ancestor of Desmodieae (crown node A; Fig. 7) most likely produced indehiscent loments (probability of 0.64; although this state is ambiguous when using parsimony (result not shown)). Lineages with dehiscent legumes evolved at least three times, exclusively in the Desmodium group. The production of indehiscent legumes is a synapomorphy of the Lespedeza group (Fig. 7). The ancestral state for the number of seeds in the fruit could neither be inferred unequivocally in the groups Desmodium, Phyllodium excluding Ougeinia (crown node D), and Lespedeza, nor in the tribe Desmodieae as a whole (Fig. 7). The extant lineages included in the Lespedeza group produce indehiscent legumes with up to three seeds. 4. Discussion 4.1. Phylogenetic relationships within Desmodieae The monophyly of the tribe Desmodieae was shown in previous studies (Bruneau et al., 1995; Kajita et al., 1996; Doyle et al., 1997; Wojciechowski et al., 2004; Egan et al., 2016; LPWG, 2017), and our analysis confirmed this result based on an unprecedented sampling. Except for the uncertain phylogenetic placement of the genus Ougeinia, the main clades identified on the cpDNA tree correspond to the three groups previously circumscribed based on both morphological and molecular characters in the tribe, i.e. Desmodium, Lespedeza, and Phyllodium. In addition, we found that the genus Kummerowia is nested within the genus Lespedeza (Figs. 2 and 3), in contrast with the results of Ohashi and Nemoto (2014). Our sampling included two accessions of O. dalbergioides Benth. in order to discard the hypothesis that the uncertain placement of Ougeinia was due to a problem when sequencing the cpDNA markers on the first accession. This monospecific genus was not included in the sampling of LPWG (2017). Regarding the tribe Desmodieae, our results were similar to those shown by LPWG (2017), although the latter study was based on a different taxonomic sampling and on a single chloroplast marker (matK). However, in our study, T. triquetrum, Akschindlium godefroyanum, and Droogmansia formed a clade together with Aphyllodium and the clade gathering the remaining accessions of the Phyllodium group (crown node E), whereas T. triquetrum was sister to all the other members of the Phyllodium group (including T. pseudotriquetrum (DC.) H. Ohashi) in LPWG (2017). Our dense genus sampling allowed showing several statistically supported conflicts between the chloroplast and nuclear topologies. Similarly, strong differences in the evolutionary history of different cellular compartments have been reported in other plant groups (e.g. Nauheimer et al., 2012; Kramina et al., 2016). Such conflicts can result from reticulate evolution, due to interspecific hybridization. Hybridization events in Desmodieae have already been reported in a few studies (e.g. Raveill, 2006; Han et al., 2010; Xu et al., 2017) and hybrid forms (in respect to taxonomically important traits such as fruit form and leaf shape) have been detected when studying herbarium specimens (C. Sarthou, pers. obs.). Other causes of incongruent chloroplast and nuclear tree topologies are incomplete lineage sorting, and particular phylogeographic structure (Rieseberg et al., 1996; Naciri and Linder, 2015). Whether these factors apply to Desmodieae is still hypothetical, and further investigations are needed. The reconstruction of ancestral states for distribution areas and morphological traits relied on the chloroplast phylogenetic tree of Desmodieae, as the topology was mostly in accordance with the circumscription of infratribal groups as proposed by Ohashi (2005) based on morphological traits, contrary to what was observed on the nuclear tree topology, where the Lespedeza group was nested within the Desmodium group. 4.2. Biogeography and life history trait evolution in Desmodieae The hypothetical common ancestor of Desmodieae most likely occurred in Asia and dates back to the Middle Oligocene, ca. 28.3 Ma. While the ancestral lineages leading to the three major clades likely remained in Asia, several colonization events towards Oceania, America, and Africa occurred later on, within the last 17.5 Ma. They were most probably mediated through long distance dispersal (LDD) events since landmasses had then already diverged for a long time (McLoughlin, 2001), excluding the potential influence of vicariance. Long distance dispersal has been shown to be a common dispersal process in Fabaceae (Lavin et al., 2004), and it is probable that the seeds drifted through ocean currents such as in the tribe Fabeae (Schaefer et al., 2012) and Mucuna (Moura et al., 2016). Nevertheless, the two colonization events from Asia to America in the Desmodium group and in the Lespedeza group occurred less than 10.0 and 14.8 Ma, respectively. This was before the Bering Strait got submerged (Brigham-Grette, 2001) and dispersal could therefore have been mediated through a land bridge. Two contrasted trends for the evolution of the habit were identified. In the Phyllodium group excluding Ougeinia, the habit tends to decrease in size, while it increases in some lineages of the Desmodium group. Both colonization events to America (giving rise to L. simulata in the Lespedeza group and to D. intortum in the Desmodium group) occurred in lineages presenting herbaceous or shrub habit. The single colonization event of Africa found in the Phyllodium group led to two Droogmansia species that differ by their habit. While Droogmansia montana Jacq.-Fél. retained the likely ancestral state (trees and shrubs), D. pteropus evolved towards lower life forms (trees, shrubs, but also subshrubs). This may be explained by niche competition between sister lineages colonizing the same area. The type of fruit is a taxonomically useful character to distinguish the species from the Lespedeza group from the other Desmodieae species, as indehiscent legumes are only found in the Lespedeza group. Within the Desmodium group, lineages with dehiscent legumes evolved once or several times from ancestors with indehiscent loments. Furthermore, in the tribe as a whole, only transitions from indehiscence to dehiscence were observed. This may indicate that reduced fruit modularity and dehiscing fruits have been selected during the evolution of Desmodieae, probably because of lower morphogenetic costs and better dispersal abilities. Indehiscent loments allow for more variability in the number of seeds per fruit than indehiscent legumes (Fig. 7). Evolving from segmented fruits (loments, the ancestral state for Desmodieae) to fruits with a single segment (a synapomorphy of the Lespedeza group) may increase structural constraints during fruit development for ovaries bearing a high number of ovules. This may explain why the Lespedeza lineage consists exclusively of species producing fruits with less than three ovules only. Modularity seems here to allow variability in the number of ovules produced in a single ovary. The dehiscent legume fruit type is apomorphic in the Desmodium group. In this group, when both the degree of fruit segmentation (loment to legume) and the mode of dehiscence (indehiscent to dehiscent) change, the number of seeds is not necessarily low. The mode of dehiscence might hence add a degree of freedom to carpel development in lineages where species producing legumes evolved from ancestors producing loments. When comparing the evolution of habit and number of seeds per fruit, it seems that more seeds are produced per fruit when plant size is high (except in the Melliniella+Alysicarpus clade). Seed production may thus be linked to the age of the individual (positively correlated with plant height in the case of trees and shrubs) or to adaptations leading to more effective dispersal (Norghauer and Newbery, 2015). 4.3. The New Caledonian endemic genera Arthroclianthus and Nephrodesmus Although the genera Arthroclianthus and Nephrodesmus were circumscribed using morphological characters (but see Ohashi et al. (1981), who noted that Arthroclianthus is scarcely distinct from Nephrodesmus), they were not respectively monophyletic based on our molecular data. A taxonomic revision of both genera is hence much needed. Arthroclianthus and Nephrodesmus either formed a clade, or were grouped together with H. ormocarpoides (sister to N. francii) and O. caudata based on the nuclear and chloroplast datasets, respectively. Oceania was likely colonized between 10.7 and 7.3 Ma by the lineage leading to the common ancestor of Arthroclianthus, Nephrodesmus, Hanslia, and Ohwia (node E in Fig. 5), and the colonization of New Caledonia necessarily occurred either at this time, or later on. This is long after the period of total oceanic submersion of the island shown by geological evidence, which ended ca. 37 Ma (Pelletier, 2007; Nattier et al., 2017), and colonization by an Asian lineage was most likely due to LDD. Such dispersal from Asia to New Caledonia was already shown in other plant groups, e.g., Piper L. (Piperaceae; Smith et al., 2008) and Diospyros L. (Ebenaceae; Turner et al., 2013). Acknowledgments We thank Sovanmoly Hul, Hervé Vandrot, and Joël Jérémie for their help in identifying herbarium specimens. We are grateful to the programs that made our work possible. It was supported by the grant ANR Biodiversité BIONEOCAL, by the ATM ‘Taxonomie moléculaire: DNA Barcode et gestion durable des collections’ and the network ‘Bibliothèque du Vivant’ funded by the CNRS, the Muséum national d’Histoire naturelle, the INRA, and the CEA (Genoscope). We thank the Editor and three anonymous reviewers for their constructive comments that greatly improved the manuscript. References Bailey, C.D., Doyle, J.J, Kajita, T., Nemoto, T., Ohashi, H., 1997. The chloroplast rpl2 intron and ORF184 as phylogenetic markers in the legume tribe Desmodieae. Syst. Bot. 22, 133–138. Brigham-Grette, J., 2001. 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Evol. 62, 346–358. Xu, B., Zeng, X.M., Gao, X.F., Jin, D.P., Zhang, L.B., 2017. ITS non-concerted evolution and rampant hybridization in the legume genus Lespedeza (Fabaceae). Sci. Rep. 7: 40057. Yu, Y., Harris, A.J., Blair, C., He, X., 2015. RASP (reconstruct ancestral state in phylogenies): a tool for historical biogeography. Mol. Phylogenet. Evol. 87, 46–49. Table captions Table 1. Generic composition, sampling ratio, and geographic distribution of the infratribal groups of the tribe Desmodieae (from: Ohashi, 2005, 2012a, 2012b; Huang et al. 2010). Table 2. List and characteristics of the species/samples included in the study, and GenBank accession numbers. Within each group, species names are ordered according to the position of the relative accession in the chloroplast phylogenetic tree. Group: D, Desmodium group; L, Lespedeza group; P, Phyllodium; O: outgroup. Sequences generated for the first time for particular species are marked with an asterisk. The genera that were sequenced for the first time (Leptodesmia and Ougeinia) are also marked with an asterisk. Voucher information includes the Paris Herbarium barcode (followed by ‘Sil’ for silica-dried samples), the geographic origin, name of the collector, and collection number. Distribution: (a) Asia; (b) Oceania; (c) Africa; (d) America; (ab) Asia and Oceania; (ac) Asia and Africa; (abc) Asia and Oceania and Africa. Habit: (1) Herb; (2) Subshrub; (3) Shrub or tree; (4) Herb and subshrub; (5) Subshrub and ‘shrub or tree’. Fruit: (1) Indehiscent loment; (2) dehiscent legume; (3) Indehiscent legume. Size of the fruit and number of seeds per fruit: (1) small fruit with up to 3 seeds; (2) average-sized fruit with up to 6 seeds; (3) long fruit with up to 7 seeds and more. References used for coding the character states are the following: Ohashi (1973), Kirkbride et al. (2003) and Lewis et al. (2005). Figure captions Fig. 1. Diversity of habits and fruit types in the tribe Desmodieae. (A) Herb: Alysicarpus ovalifolius (Desmodium group; one individual from the specimen Labat 3952, Paris Herbarium (P), barcode P00577613), (B) Subshrub: Uraria crinita (Desmodium group; credit: Sovanmoly Hul), (C) Shrub: Nephrodesmus sericeus (Desmodium group; credit: JeanNoël Labat, Labat 3913 (P), P00609010), (D) Tree: Arthroclianthus angustifolius (Phyllodium group; credit: J.N. Labat), (E) Indehiscent loment: Desmodium intortum (Desmodium group; credit: J.N. Labat, Labat 3797 (P), P00527423), (F) Indehiscent loment: Alysicarpus ovalifolius (Desmodium group; fruits from the specimen Labat 3952 (P), P00758171), (G) Dehiscent legume: Mecopus nidulans (Desmodium group; fruits from the specimen Cheng, David & Leti CL721 (P), P00625251), (H) Dehiscent legume: Pseudarthria hookeri (Desmodium group; fruits from the specimen Jongkind 2462 (P), P03496356), (I) Dehiscent legume: Melliniella micrantha (Desmodium group; fruits from the specimen Raynal-Roques 22514 (P), P03091983), (J) Indehiscent loment: Nephrodesmus francii (Phyllodium group; credit: J.N. Labat, Labat 3932 (P), P00609037), (K) Indehiscent loment: Arthroclianthus deplanchei (Phyllodium group; credit: J.N. Labat, Labat 3915 (P), P00609013), (L) Indehiscent loment: Tadehagi triquetrum (Phyllodium group; credit: S. Hul), (M) Indehiscent loment: Phyllodium pulchellum (Phyllodium group; credit: S. Hul), (N) Indehiscent legume: Campylotropis polyantha (Lespedeza group; fruits from the specimen Soulié 3968 (P), P03089856). Fig. 2. Phylogenetic tree of the tribe Desmodieae obtained with Bayesian inference from a 62accession and 1444-position long alignment of concatenated psbA-trnH and rbcL chloroplast sequences. Posterior probability values >0.8 and bootstrap supports >70% are indicated. Nodes that are discussed in the text are noted A to H. The Phyllodium (P), Desmodium (D), and Lespedeza (L) groups are indicated. Lineages belonging to the P, D, and L groups that are incongruently placed in the nuclear tree of Fig. 3 are highlighted with shades of green, blue, and pink, respectively. Fig. 3. Phylogenetic tree of the tribe Desmodieae obtained with Bayesian inference from a 62accession and 381-position long alignment of ITS-1 nuclear sequences. Posterior probability values >0.8 and bootstrap supports >70% are indicated. The Phyllodium (P), Desmodium (D), and Lespedeza (L) groups are indicated. Lineages belonging to the P, D, and L groups that are incongruently placed in the chloroplast tree of Fig. 2 are highlighted with shades of green, blue, and pink, respectively. Fig. 4. Chronogram of the tribe Desmodieae obtained under a Bayesian relaxed clock with log-normally distributed rates (cpDNA matrix of 62 accessions, 1444 positions). Bars around node ages indicate the 95% highest posterior density intervals. Nodes that are discussed in the text are noted A to H. The Phyllodium (P), Desmodium (D), and Lespedeza (L) groups are indicated. Fig. 5. Evolution of the distribution area of the tribe Desmodieae inferred under the DEC model using RASP v.3.2 on the chloroplast tree obtained with Bayesian inference. Nodes that are discussed in the text are noted A to H. The colored bars refer to the Phyllodium (green), Desmodium (blue), and Lespedeza (pink) groups. Fig. 6. Evolution of habit in the tribe Desmodieae inferred under maximum likelihood optimization on the 61-accession tree obtained with Bayesian inference. Nodes that are discussed in the text are noted A to H. The colored bars refer to the Phyllodium (green), Desmodium (blue), and Lespedeza (pink) groups. Fig. 7. Evolution of fruit type and number of seeds per fruit in the tribe Desmodieae inferred under maximum likelihood optimization on the 61-accession chloroplast tree obtained with Bayesian Inference. Nodes that are discussed in the text are noted A to H. The colored bars refer to the Phyllodium (green), Desmodium (blue), and Lespedeza (pink) groups. Infratribal groups of Desmodieae Genera Sampling ratio Distributional range Alysicarpus Christia Codariocalyx Desmodium Desmodiastrum Eliotis Hegnera Hylodesmum Leptodesmia Mecopus Melliniella Monarthrocarpus Ototropis Pseudarthria Pycnospora Trifidacanthus Uraria 2/25-30 3/ca. 10 1/2 5/ca. 260 0/4 0/2 1/1 3/14 1/3 1/3 1/2 0/1 0/13 1/3-4 0/1 0/1 3/ca. 20 Africa, Asia (China, India, Japan, Malesia, South-East Asia), Oceania (Australia) Asia (China, India, Malesia, South-East Asia), Oceania (Australia) Asia (China, India, Malesia, South-East Asia, Sri Lanka, Taiwan) Africa (Madagascar), America, Asia, Oceania Asia (India, Malesia) Asia (India, South-East Asia, Sri Lanka) Asia (Malesia, South-East Asia) Africa, America (East North America), Asia (East Asia, India through China) Africa (Madagascar), Asia (India) Asia (India, Malesia, South China, South-East Asia) Africa (Central and West Africa) Asia (East Malesia), Oceania (Papua New Guinea) Asia, Oceania Africa, Asia (India, Malesia) Africa (East Africa, Somalia), Asia (East and South-East Asia, India), Oceania (Austral Asia (Malesia, South China, South-East Asia) Africa, Asia (India, Malesia, South China, South-East Asia, Taiwan) Akschindlium 1/1 Asia (South-East Asia) Desmodiinae subtribe Desmodium Group (11 genera studied/17 genera in total) Phyllodium Group (11/12) Aphyllodium 1/7 Arthroclianthus Dendrolobium Droogmansia Hanslia Nephrodesmus Ohwia Ougeinia Phyllodium Tadehagi Verdesmum 10/ca. 30 2/18 2/ca. 5 1/2 4/5 1/2 1/1 3/8 1/ca. 6 0/1 Asia (India, Malesia, South China, South-East Asia, Sri Lanka), Oceania (Australia, Pa Guinea) Oceania (endemic to New Caledonia) Asia (India to Japan, Malesia, South-East Asia), Oceania (Australia) Africa (Central to South Central Africa) Oceania (Australia, Papua New Guinea, Vanuatu), Asia (Malesia) Oceania (endemic to New Caledonia) Asia (China to Japan, India, Malesia, South-East Asia) Asia (India and West Nepal) Asia (East and South-East Asia, India), Oceania (North Australia) Asia (India to South-East Asia, China, Malesia), Oceania (North Australia) Oceania (Papua New Guinea) Campylotropis Kummerowia Lespedeza 5/ca. 37 1/2 2/ ca. 35 Asia (India to South-East Asia, China) Asia (East Asia) Asia (China, East Asia, India, Malesia), America (North America) Lespedezinae subtribe Lespedeza Group (3/3) Taxa Group P barcode Origin and voucher Desmodieae GenBank accession numb rbcL psbA-tr KY702606 KY702607 KY702608* KY702609* KY702610 KY702611* KY702612 MF084 MF084 MF084 MF084 MF084 MF084 MF084 KY702613 KY702614* MF084 MF084 KY702615 KY702616* KY702617 KY702618* MF084 MF084 MF084 MF084 Alysicarpus bupleurifolius (L.) DC. Alysicarpus ovalifolius (Schumach.) J. Léonard Christia convallaria (Schindl.) H. Ohashi Christia obcordata (Poir.) Bakh. f. ex Meeuwen Christia vespertilionis (L. f.) Bakh. f. ex Meeuwen Codariocalyx gyroides (Roxb. ex Link) X.Y. Zhu Desmodium adscendens (Sw.) DC. D D D D D D D P03114294 P00577613 P03089594 P03089572 P00633105 P00695519 P03623122 Desmodium heterocarpon (L.) DC. Desmodium heterophyllum (Willd.) DC. D D P00695889 P03623154 Desmodium intortum (Mill.) Urb. Desmodium velutinum (Willd.) DC. Hegnera obcordata (Miq.) Schindl. Hylodesmum oldhamii (Oliv.) H. Ohashi & R.R. Mill Hylodesmum podocarpum (DC.) H. Ohashi & R.R. Mill Hylodesmum repandum (Vahl) H. Ohashi & R.R. Mill Leptodesmia congesta Baker* Mecopus nidulans Benn. Melliniella micrantha Harms Pseudarthria hookeri Wight & Arn. Uraria crinita (L.) Desv. ex DC. Uraria lagopodioides (L.) DC. Uraria rufescens (DC.) Schindl. Campylotropis bonii Schindl. Campylotropis delavayi (Franch.) Schindl. Campylotropis macrocarpa (Bunge) Rehder Campylotropis polyantha (Franch.) Schindl. Campylotropis sargentiana Schindl. Kummerowia striata (Thunb.) Schindl. Lespedeza juncea (L. f.) Pers. Lespedeza simulata Mack. & Bush Akschindlium godefroyanum (Kuntze) H. Ohashi Aphyllodium biarticulatum (L.) Gagnep. Arthroclianthus balansae Schindl. Arthroclianthus sanguineus Baill. Arthroclianthus macrobotryosus Hochr. Arthroclianthus obovatus Hochr. Arthroclianthus deplanchei Hochr. Arthroclianthus angustifolius Hochr. Arthroclianthus leratii Schindl. Arthroclianthus cuneatus Schindl. Arthroclianthus andersonii Schindl. D D D D P00527423 P00181647 P00096071 P02937755 Thailand, A.F.G. Kerr 16207 Mauritania, J.-N. Labat et al. 3952 Vietnam, E. Poilane 12517 Thailand, T. Sørensen et al. 2493 Cambodia, Cheng et al. CL683 Cambodia, M. Newman et al. 2233 New Caledonia, M. Baumann-Bodenheim & A. Guillaumin 7945 Cambodia, M. Newman et al. 2139 New Caledonia, M. Baumann-Bodenheim & A. Guillaumin 12157 Comoros, J.-N. Labat et al. 3797 Mayotte, M. Pignal 1294 Thailand, C.F. van Beusekom et al. 4135 Japan, G. Murata 18538 D P02939195 Korea, V. Komaròv 960 KY702619 MF084 D P02938380 Laos, E. Poilane 28355 KY702620* MF084 D D D D D D D L L L L L L L L P P P P P P P P P P P P00533699 P00625251 P03091983 P03496356 P00626168 P03103654 P02756238 P03089256 P03089355 P03089856 P03089792 P02751711 P03993515 P02751576 P00093355 P00096063 P02296319 P02296349 P02296664 P02296557 P02296383 P02296294 P02296411 P02296353 P02296282 Madagascar, J.-N. Labat et al. 3655 Cambodia, K.C. Cheng et al. CL721 Mali, A. Raynal-Roques 22514 Ghana, C.C.H. Jongkind 2462 Cambodia, C. Long et al. CL314 China, Hong Kong, J.P.W. Woo & T.K. Woo 647 Thailand, C.F. van Beusekom & C. Charoenpol 1987 Thailand, K. Larsen et al. 42555 China, G. Forrest 16948 Cultivated, MNHN Garden, Paris China, Tibet, J.A. Soulié 3968 China, W.P. Fang 3504 Japan, M. Togashi 589 Japan, H. Ohashi s.n. USA, D. Demaree 36231 Thailand, K. Larsen et al. 31817 Cambodia, Porée-Maspero 242 New Caledonia, J.M. Veillon 6127 New Caledonia, G.L. Webster 18371 New Caledonia, V. Hequet 3627 New Caledonia, T. Jaffré 3291 New Caledonia, T. Jaffré et al. 3624 New Caledonia, H.S. MacKee 12283 New Caledonia, A.J. Le Rat 454 New Caledonia, E.-I. Franc 2500 New Caledonia, G.D. McPherson 6511 KY702621* KY702622 KY702623* KY702624 KY702625 KY702626 KY702627* KY702628* KY702629* KY702630 KY702631* KY702632* KY702633 KY702634* KY702635* KY702639* KY702640* KY702641* KY702642* KY702643* KY702644* KY702603* KY702601* KY702604* KY702602* KY702600* MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 MF084 Arthroclianthus maximus Schindl. P P00749540 (Sil) P00606856 P00626170 P03092480 P03092476 P00591396 New Caledonia, J.-N. Labat et al. 4029 KY702605* MF084 Dendrolobium lanceolatum (Dunn) Schindl. Dendrolobium triangulare (Retz.) Schindl. Droogmansia montana Jacq.-Fél. Droogmansia pteropus (Baker) De Wild. Hanslia ormocarpoides (DC.) H. Ohashi P P P P P Cambodia, C. Long & K.C. Cheng CL024 Cambodia, C. Long et al. CL316 Guinea, H. Jacques-Félix 1959 Burundi, M. Reekmans 6409 Vanuatu, M. Pignal & F. Brunois 2771 KY702645 KY702646 KY702647* KY702648* KY702649* MF084 MF084 MF084 MF084 MF084 Nephrodesmus francii (Harms) Schindl. P New Caledonia, J.-N. Labat et al. 3933 KY702650* MF084 New Caledonia, J. Munzinger et al. 3011 KY702651* MF084 New Caledonia, J.-N. Labat et al. 3913 KY702652* MF084 New Caledonia, J.-N. Labat et al. 3503 KY702638* MF084 P P P P P P P P00609041 (Sil) P02296269 (Sil) P00609010 (Sil) P00454765 (Sil) P03993618 P02396263 P02396256 P00625262 P00606870 P00625078 P00695517 Nephrodesmus ferrugineus Daniker P Nephrodesmus sericeus Schindl. P Nephrodesmus parvifolius Schindl. P Ohwia caudata (Thunb.) H. Ohashi Ougeinia dalbergioides Benth.* Ougeinia dalbergioides Benth.* Phyllodium elegans (Lour.) Desv. Phyllodium longipes (Craib) Schindl. Phyllodium pulchellum (L.) Desv. Tadehagi triquetrum (L.) H. Ohashi Phaseoleae Phaseolus vulgaris L. Vigna radiata (L.) R. Wilczek Milletieae Fordia cauliflora Hemsl. Muellera frutescens (Aubl.) Standl. Japan, H. Kanai 666 India, J.D. Hooker s.n. India, R. Strachey & J.E. Winterbottom 2 Cambodia, K.C. Cheng et al. CL712 Cambodia, C. Long & K.C. Cheng CL037 Cambodia, K.C. Cheng et al. CL807 Cambodia, M. Newman et al. 2111 KY702653* KY702654* KY702655 KY702656 KY702657* KY702658* KY702659 MF084 MF084 MF084 MF084 MF084 MF084 MF084 O O - NC_009259 NC_013843 NC_00 NC_01 O O P02942273 P03088013 KY702636 KY702637 MF084 MF084 China, Hong-Kong, K.Y. Chan 108 Colombia, H.P. Fuchs & L. Zanella 21740 Highlights > We present phylogenies of Desmodieae (Fabaceae) based on a large generic sampling. > The Lespedeza group was nested within the Desmodium group based on ITS-1. > The ancestor of Desmodieae likely an Asian shrub or tree with indehiscent loments. > New Caledonia (NC) was colonized once, < ca. 10.7 Ma, by an Asian lineage through LDD. > The NC endemic genera Arthroclianthus and Nephrodesmus were not monophyletic. Graphical abstract