MelastomaTRAITs 1.0: A database of functional traits in Melastomataceae, a large pantropical angiosperm family.

The recent availability of open-access repositories of functional traits has revolutionized trait-based approaches in ecology and evolution. Nevertheless, the underrepresentation of tropical regions and lineages remains a pervasive bias in plant functional trait databases, which constrains large-scale assessments of plant ecology, evolution, and biogeography. Here, we present MelastomaTRAITs 1.0, a comprehensive and updatable database of functional traits for the pantropical Melastomataceae, the ninth-largest angiosperm family with 177 genera and more than 5800 species. Melastomataceae encompass species with a wide diversity of growth forms (herbs, shrubs, trees, epiphytes, and woody climbers), habitats (including tropical forests, savannas, grasslands, and wetlands from sea level to montane areas above the treeline), ecological strategies (from pioneer, edge-adapted and invasive species to shade-tolerant understory species), geographic distribution (from microendemic to continental-wide distribution), reproductive, pollination, and seed dispersal systems. MelastomaTRAITs builds on 581 references, such as taxonomic monographs, ecological research, and unpublished data, and includes four whole-plant traits, six leaf traits, 11 flower traits, 18 fruit traits, and 27 seed traits for 2520 species distributed in 144 genera across all 21 tribes. Most data come from the Neotropics where the family is most species-rich. Miconieae (the largest tribe) contains the highest number of trait records (49.6%) and species (41.1%) records. The trait types with the most information in the database were whole-plant traits, flowers, and leaf traits. With the breadth of functional traits recorded, our database helps to fill a gap in information for tropical plants and will significantly improve our capacity for large-scale trait-based syntheses across levels of organization, plant-animal interactions, regeneration ecology, and thereby support conservation and restoration programs. There are no copyright restrictions on the dataset; please cite this data paper when reusing the data.

Phylogenetic relationships of Indian Memecylon L. (Melastomataceae) based on nrDNA ITS and cpDNA rbcL sequence data.

Memecylon (Melastomaceae) is a large genus of the Old-World predominantly woody species. Many species of Memecylon are used for timber, ornamental and medicinal purposes. The objective of the present study was to undertake a phylogenetic analysis of Indian Memecylon based on nuclear ribosomal DNA internal transcribed spacer (nrDNA-ITS) and rbcL sequence data. Sampling included 26 species and one variety (20 endemics) representing 67% of the total Indian species. Molecular phylogeny data for analysed species revealed that the Indian Memecylon is monophyletic. Monophyly is strongly supported in the ITS, rbcL and ITS + rbcL combined analyses. Memecylon species are grouped in a major clade with strong support in ITS sequence data and moderate support in combined ITS + rbcL analyses.

Natural hybridization between Phyllagathis and Sporoxeia species produces a hybrid without reproductive organs.

Natural hybridization plays important roles in plant evolution and speciation. In this study, we sequenced ribosomal internal transcribed spacer (nrITS), four low-copy nuclear genes (Dbr1, SOS4a, SOS4b and PCRF1) and the chloroplast intergenic spacer trnV-trnM to test the hypothesis of hybridization between two species of Phyllagathis and Sporoxeia (Sonerileae/Dissochaeteae, Melastomataceae). Our results provided compelling evidence for the hybridization hypothesis. All hybrid individuals sampled were first-generation hybrids. The failure of flower production in the F1 hybrid individuals may work as the barrier preventing later-generation hybridization or backcross. Analysis of the chloroplast trnV-trnM sequences showed that the hybridization is bidirectional with S. petelotii as the major maternal parent. Several factors, such as sympatry, similar habitat preference, overlapping flowering season and shared pollinators, might have contributed to this hybridization event. The "intergeneric" hybridization reported in this study suggests close relationship between P. longicalcarata and S. petelotii.

Controls on foliar aluminium accumulation among populations of the tropical shrub Melastoma malabathricum L. (Melastomataceae).

Aluminium (Al) accumulation is a common trait expressed in at least 60 plant families and particularly prevalent in tropical woody plants. However, the functional significance and genetic or physiological controls on Al accumulation are currently unknown. We tested the hypothesis that differential expression of Al accumulation among wild populations of the Al-accumulating tropical shrub Melastoma malabathricum L. is associated with habitat-related variation in total and exchangeable soil Al concentrations. Mature leaves and seeds were sampled from 20 populations of M. malabathricum growing in six habitats across Peninsular Malaysia, and soil was collected from each site. The seeds were grown in hydroponic solutions comprising 50% Hoagland's solution amended with Al in the form of 1.0 mM AlCl3 to test the hypothesis that differential expression of foliar Al accumulation is an inherited trait. Foliar Al concentrations varied significantly among populations, but were not consistently different among plants growing in different habitats and showed no relationship to total or exchangeable Al concentrations in soils collected at the 20 sites. Mean foliar Al concentration in wild plants was positively correlated with foliar calcium (Ca) concentrations, and with total soil nitrogen (N), Ca and magnesium (Mg) concentrations, across the 20 populations, and Al addition increased foliar concentrations of phosphorus, Ca, Mg and potassium in seedlings. The differential expression of Al accumulation in M. malabathricum populations is uncoupled to local variation in soil Al concentrations, but may be sensitive to local soil-related variation in the availability of other macro-nutrients, in particular N, Ca and Mg. Further research on the factors controlling Al uptake should focus on the plasticity of this trait within populations of Al accumulators and interactions with micro-habitat variation in the availability of the macronutrient cations.

Unexpectedly high genetic diversity and divergence among populations of the apomictic Neotropical tree Miconia albicans.

Since tropical trees often have long generation times and relatively small reproductive populations, breeding systems and genetic variation are important for population viability and have consequences for conservation. Miconia albicans is an obligate, diplosporous, apomictic species widespread in the Brazilian Cerrado, the savanna areas in central Brazil and elsewhere in the Neotropics. The genetic variability would be, theoretically, low within these male-sterile and possibly clonal populations, although some variation would be expected due to recombination during restitutional meiosis. We used ISSR markers to assess genetic diversity of M. albicans and to compare with other tropical trees, including invasive species of Melastomataceae. A total of 120 individuals from six populations were analysed using ten ISSR primers, which produced 153 fully reproducible fragments. The populations of M. albicans presented mean Shannon's information index (I) of 0.244 and expected heterozygosity (He ) of 0.168. Only two pairs of apparently clonal trees were identified, and genetic diversity was relatively high. A hierarchical amova for all ISSR datasets showed that 74% of the variance was found among populations, while only 26% of the variance was found within populations of this species. Multivariate and Bayesian analyses indicated marked separation between the studied populations. The genetic diversity generated by restitutional meiosis, polyploidy and possibly other genome changes may explain the morpho-physiological plasticity and the ability of these plants to differentiate and occupy such a wide territory and different environmental conditions. Producing enormous amounts of bird-dispersed fruits, M. albicans possess weedy potential that may rival other Melastomataceae alien invaders.

Naturally fragmented and isolated distribution in subtropical grassland patches affects genetic diversity and structure at different spatial scales: The case of Tibouchina hatschbachii, an endemic shrub from Brazil.

PREMISE OF THE STUDY: The genetic structure of organisms results from the interactions between life history traits and the ecological and demographic characteristics of the landscape that shape the intra- and interpopulation genetic variation in space and time. In this study, we used a species restricted to islands of grassland vegetation in southern Brazil to investigate the effects of its naturally fragmented distribution on diversity and genetic structure patterns. METHODS: Diversity and intra- and interpopulational genetic structure were analyzed using polymorphisms of eight nuclear microsatellite markers in 205 individuals of T. hatschbachii and Bayesian and multivariate methods. KEY RESULTS: At the intrapopulation level, populations presented low genetic diversity and strong spatial genetic structure, indicating a greater spatial autocorrelation until ∼50-500 m. At the interpopulation level, genetic variation partitioned into two geographically structured genetic clusters. Gene flow through pollen was more efficient than gene flow by seeds. CONCLUSIONS: Genetic structure was influenced locally by seed and pollen dispersal dynamics and regionally by fragmentation of the grassland landscape. This study highlights the importance of geological barriers, and potentially a role for genetic drift, in influencing diversification of species in subtropical grasslands of southern Brazil.

Identification and genetic diversity analysis of Memecylon species using ISSR, RAPD and Gene-Based DNA barcoding tools

Background: Memecylon species are commonly used in Indian ethnomedical practices. The accurate identification is vital to enhance the drug's efficacy and biosafety. In the present study, PCR based techniques like RAPD, ISSR and DNA barcoding regions, such as 5s, psbA-trnH, rpoC1, ndh and atpF-atpH, were used to authenticate and analyze the diversity of five Memecylon species collected from Western Ghats of India. Results: Phylogenetic analysis clearly distinguished Memecylon malabaricum from Memecylon wightii and Memecylon umbellatum from Memecylon edule and clades formed are in accordance with morphological keys. In the RAPD and ISSR analyses, 27 accessions representing five Memecylon species were distinctly separated into three different clades. M. malabaricum and M. wightii grouped together and M. umbellatum, M. edule and Memecylon talbotianum grouped in the same clade with high Jaccard dissimilarity coefficient and bootstrap support between each node, indicating that these grouped species are phylogenetically similar. Conclusion: Data from the present study reveals that chloroplast psbA-trnH region could be used as a potential candidate region for identifying Memecylon species, and ISSR marker system could be used for estimating genetic diversity since it has high percent polymorphism compared to RAPD marker.

Diversity and constraints in the floral morphological evolution of Leandra s.str. (Melastomataceae).

BACKGROUND AND AIMS: Putative processes related to floral diversification and its relation to speciation are still largely unaccounted for in the Melastomataceae. Leandra s.str. is one of the most diverse lineages of the Neotropical Miconieae and ranks among the ten most diverse groups in the Atlantic Forest. Here, we describe the floral diversity of this lineage in a continuous framework and address several questions related to floral evolution and putative developmental and environmental constraints in its morphology. METHODS: The morphological data set includes individual size measurements and shape scores (from elliptical Fourier analysis) for hypanthia, petals, stamens and styles. We evaluate whether there is evidence of correlation among these floral structures, shifts and convergent patterns, and association of these traits with elevation. KEY RESULTS: Leandra s.str. flower structures present a strong phylogenetic signal and tend to be conserved among close relatives. The extremes in flower regimes seem to be quite distinct, but non-overlapping discrete flower types are not observed. Overall, the morphology of Leandra s.str. floral structures is correlated, and anther colour and inflorescence architecture correlate with flower structures. Additionally, the rates of species diversification and morphological evolution are correlated in most clades. CONCLUSIONS: Although some flower regimes tend to occur in different elevational ranges, no significant association is observed. The general idea that hypanthium-ovary fusion is associated with fruit types in the Melastomataceae does not hold for Leandra s.str., where, instead, hypanthium-ovary fusion seems to be associated with anther shape. The lowest rate of flower morphological change, when compared with species diversification rates, is observed in the clade that possesses the most specialized flowers in the group. While stuck on a single general pollination system, Leandra s.str. seems to be greatly wandering around it, given the flower diversity and convergent patterns observed in this group.

Development and characterization of microsatellite markers for Tibouchina hatschbachii (Melastomataceae), an endemic and habitatrestricted shrub from Brazil / Desenvolvimento e caracterização de marcadores microssatélites para Tibouchina hatschbachii (Melastomataceae), um arbusto endêmico e com restrição de habitat da região subtropical do Brasil

Tibouchina hatschbachii Wurdack (Melastomataceae) is an autogamous shrub restricted to granite (GO) and sandstone (SO) rock outcrops from subtropical Brazil. We designed primers for the amplification of microsatellite regions for T. hatschbachii, and characterized these primers to estimate genetic diversity parameters and contemporary genetic structure patterns. Eight loci were successfully amplified and were characterized using 70 individuals from three natural populations. Polymorphic information content ranged from 0.200 to 0.772 per locus. All loci were polymorphic, with allele numbers ranging from two to eight. The low degree of polymorphism may be explained by the fact that T. hatschbachii has disjunct populations and a recent genetic bottleneck, and also that it is self-pollinated. The observed and expected heterozygosities ranged from 0.115 to 1.000 and from 0.112 to 0.800, respectively. We observed private alleles in all loci. These are important features that enable us to identify population differentiation and help to us understand gene flow patterns for T. hatschbachii in subtropical Brazil. Eight microsatellite loci from other species of Tibouchina amplified positively in T. hatschbachii.

Tibouchina hatschbachii Wurdack (Melastomataceae) é um arbusto autógamo, com ocorrência restrita em afloramentos rochosos graníticos (GO) e areníticos (SO) na região subtropical do Brasil. Neste trabalho, foram desenvolvidos marcadores para a amplificação de regiões microssatélites para T. hatschbachii e caracterizados esses primers para estimar parâmetros de diversidade genética. Oito loci foram amplificados com sucesso e caracterizados, utilizando 70 indivíduos de três populações naturais. O conteúdo de informação polimórfica variou de 0,200 a 0,772 por locus. Todos os loci foram polimórficos, com números de alelos que variam de dois a oito. O baixo grau de polimorfismo pode ser explicado pelo fato de que T. hatschbachii possui populações disjuntas e uma história recente de gargalo genético populacional, e também pelo fato de apresentar um sistema reprodutivo de autopolinização, tendendo a favorecer a baixa variação. As heterozigosidades observadas e esperadas variaram entre 0,115-1,000 e 0,112-0,800, respectivamente. Também foi observada a presença de alelos privados em todos os loci. Estas são características importantes que nos permitirão identificar a diferenciação entre populações e poderão ajudar na compreensão dos padrões de fluxo gênico atual de T. hatschbachii na região subtropical do Brasil. Oito loci microssatélites de outras espécies de Tibouchina amplificaram

Shifts from specialised to generalised pollination systems in Miconieae (Melastomataceae) and their relation with anther morphology and seed number.

Most species in Melastomataceae have poricidal anthers related to specialised bee buzz-pollination, while some have anthers with large openings associated to non-bee pollination systems. We tracked the evolution of anther morphology and seed number on the Miconieae phylogenetic tree to understand the evolutionary shifts in such pollination systems. Anther morphometric data and seed number were recorded for 54 taxa. Pollinators (bees, flies, wasps) were recorded for 20 available species. Ancestral state reconstruction was made using Maximum Likelihood from nrITS sequences. We used phylogenetic eigenvector regressions to estimate phylogenetic signal and the adaptive component for these traits. Species pollinated by bees or bees and wasps tend to have smaller pores and fruits with more seeds. Species pollinated by flies or flies and bees and/or wasps tend to have larger pores and fruits with less seeds. Independent evolution occurred three times for anthers with large pores and twice for fruits with few seeds. We detected a phylogenetic signal in both traits, and negative correlated evolution between them. In actinomorphic small-flowered Miconieae, changes in anther morphology can be related to generalisation in the pollination system incorporating flies and wasps as pollinators and lessening the importance of buzzing bees in such process. Differences in pollen removal and deposition may explain differences in anther morphology and seed number in Miconieae.

Divergence times, historical biogeography, and shifts in speciation rates of Myrtales.

We examine the eudicot order Myrtales, a clade with strong Gondwanan representation for most of its families. Although previous phylogenetic studies greatly improved our understanding of intergeneric and interspecific relationships within the order, our understanding of inter-familial relationships still remains unresolved; hence, we also lack a robust time-calibrated chronogram to address hypotheses (e.g., biogeography and diversification rates) that have implicit time assumptions. Six loci (rbcL, ndhF, matK, matR, 18S, and 26S) were amplified and sequenced for 102 taxa across Myrtales for phylogenetic reconstruction and ten fossil priors were utilized to produce a chronogram in BEAST. Combretaceae is identified as the sister clade to all remaining families with moderate support, and within the latter clade, two strongly supported groups are seen: (1) Onagraceae+Lythraceae, and (2) Melastomataceae+the Crypteroniaceae, Alzateaceae, Penaeaceae clade along with Myrtaceae+Vochysiaceae. Divergence time estimates suggest Myrtales diverged from Geraniales ∼124Mya during the Aptian of the Early Cretaceous. The crown date for Myrtales is estimated at ∼116Mya (Albian-Aptian). BioGeoBEARS showed significant improvement in the likelihood score when the "jump dispersal" parameter was added. South America and/or Africa are implicated as important ancestral areas in all deeper nodes. BAMM analyses indicate that the best configuration included three significant shifts in diversification rates within Myrtales: near the crown of Melastomataceae (∼67-64Mya), along the stem of subfamily Myrtoideae (Myrtaceae; ∼75Mya), and along the stem of tribe Combreteae (Combretaceae; ∼50-45Mya). Issues with conducting diversification analyses more generally are examined in the context of scale, taxon sampling, and larger sets of phylogenetic trees.

Untangling the phylogeny of Leandra s.str. (Melastomataceae, Miconieae).

Phylogenetic studies in Melastomataceae have demonstrated the need for taxonomic rearrangements in the current classification. Nonetheless, melastomes are among the most diverse groups of plants and several cases of known artificial taxa have been observed and awaiting further resolution. The Leandra s.str. clade, with ca. 200 species, includes the majority of the taxa traditionally treated in the genus Leandra and is almost restricted to eastern Brazil. In earlier studies, some attempts have been made to infer the relationships within Leandra s.str., but the sampling was sparse and the resolution low inside the clade. Here, we attempt to provide an improved phylogenetic hypothesis for this group on which to base further studies. Specifically, we provide a comprehensive taxon sampling and attempt to infer a species tree for this group, dissecting potential noise in the phylogenetic reconstruction, such as paralogy, rogue taxa, hybridization and incomplete lineage sorting. Our data set includes 126 ingroup species (192 terminals) and four partitions (six markers). We implement the (∗)BEAST model for species tree inference and perform several simulation methods to assess model fit and to discuss potential causes for the observed patterns. Major lineages of Leandra s.str. were delineated, a strictly bifurcating species tree model seems to not account for the observed data, and hybridization is very likely an important evolutionary force in this group.

Seed diversity in the tribe Miconieae (Melastomataceae): taxonomic, systematic, and evolutionary implications.

Miconieae is the largest tribe in the Melastomataceae with over 1,850 species. The members of Miconieae display a wide range of morphological diversity, and seed morphology is no exception. Previous studies have found that seed morphological diversity is not congruent with traditional classifications, and suggest that it may reflect evolutionary relationships within Miconieae. Here we characterize seed morphology of 364 species of Miconieae. The morphological data set and a DNA sequence data matrix were analyzed under a parsimony and Bayesian framework. Seed characters were used to test taxonomic and clade hypotheses, to estimate morphological ancestral character states, and to assess phylogenetic signal. The phylogenetic analyses of morphological data retrieved a poorly-resolved, low-supported phylogeny; in contrast, a relatively strongly supported phylogeny was estimated using the molecular data. Hypothesis testing procedures could only reject the monophyly of Clidemia, Leandra, and Miconia. The results indicated that the seed morphological characters were homoplasious, but contained phylogenetic signal. The morphological seed types that were described in previous studies did not support any of the clades retrieved by the molecular phylogeny. In contrast with previous investigations, our study shows that although seed morphology is very variable, it does not provide information for supporting some genera or clades within Miconieae. However, it is suggested that seed characters in combination with other vegetative and reproductive traits may aid in the characterization of smaller clades. The presence of phylogenetic signal retrieved by homoplasious characters may indicate that diversification of seed characters could have an adaptive component. Further studies that increase taxon sampling, refine seed trait characterization, and evaluate the alleged relationships between environmental variables and seed diversification will contribute to a better understanding of seed morphology and evolution in this species-rich tribe.

Extensive hybridization and introgression between Melastoma candidum and M. sanguineum.

Natural hybridization can lead to various evolutionary outcomes in plants, including hybrid speciation and interspecific gene transfer. It can also cause taxonomic problems, especially in plant genera containing multiple species. In this study, the hybrid status of Melastoma affine, the most widespread taxon in this genus, and introgression between its putative parental species, M. candidum and M. sanguineum, were assessed on two sites, Hainan and Guangdong, using 13 SSR markers and sequences of a chloroplast intergenic spacer. Bayesian-based STRUCTURE analysis detected two most likely distinct clusters for the three taxa, and 76.0% and 73.9% of the morphologically identified individuals of M. candidum and M. sanguineum were correctly assigned, respectively. 74.5% of the M. affine individuals had a membership coefficient to either parental species between 0.1 and 0.9, suggesting admixture between M. candidum and M. sanguineum. Furthermore, NewHybrids analysis suggested that most individuals of M. affine were F2 hybrids or backcross hybrids to M. candidum, and that there was extensive introgression between M. candidum and M. sanguineum. These SSR data thus provides convincing evidence for hybrid origin of M. affine and extensive introgression between M. candidum and M. sanguineum. Chloroplast DNA results were consistent with this conclusion. Much higher hybrid frequency on the more disturbed Guangdong site suggests that human disturbance might offer suitable habitats for the survival of hybrids, a hypothesis that is in need of further testing.

Development of microsatellite markers for the endangered Neotropical tree species Tibouchina papyrus (Melastomataceae).

We isolated and characterized 12 microsatellite loci for Tibouchina papyrus (Melastomataceae), an endangered species with narrow and disjunct range, endemics to a few localities in "cerrado rupestre" from Central Brazil. These microsatellites were obtained by sequencing of a genomic shotgun library for primer design. Leaves from 96 individuals collected in the three known local populations were genotyped using the 12 primers designed to analyze the polymorphisms at each locus. The number of alleles per locus ranged from one to six; two loci were monomorphic. Among the polymorphic loci, expected heterozygosities ranged from 0.161 to 0.714. Combined paternity exclusion probability was 0.957 and combined genetic identity (0.051) was high for studies on parentage. Tibouchina papyrus is a rare and endemic tree species of outcrop quartzite and sandstone soils, with highly isolated populations, which may have lead to the low degree of polymorphism that we detected. Also, motifs of most loci are larger than dinucleotide, which typically display lower levels of polymorphism.

Native bees mediate long-distance pollen dispersal in a shade coffee landscape mosaic.

Coffee farms are often embedded within a mosaic of agriculture and forest fragments in the world's most biologically diverse tropical regions. Although shade coffee farms can potentially support native pollinator communities, the degree to which these pollinators facilitate gene flow for native trees is unknown. We examined the role of native bees as vectors of gene flow for a reproductively specialized native tree, Miconia affinis, in a shade coffee and remnant forest landscape mosaic. We demonstrate extensive cross-habitat gene flow by native bees, with pollination events spanning more than 1,800 m. Pollen was carried twice as far within shade coffee habitat as in nearby forest, and trees growing within shade coffee farms received pollen from a far greater number of sires than trees within remnant forest. The study shows that shade coffee habitats support specialized native pollinators that enhance the fecundity and genetic diversity of remnant native trees.

Multiple Miocene Melastomataceae dispersal between Madagascar, Africa and India.

Melastomataceae sensu stricto (excluding Memecylaceae) comprise some 3000 species in the neotropics, 1000 in Asia, 240 in Africa, and 230 in Madagascar. Previous family-wide morphological and DNA analyses have shown that the Madagascan species belong to at least three unrelated lineages, which were hypothesized to have arrived by trans-oceanic dispersal. An alternative hypothesis posits that the ancestors of Madagascan, as well as Indian, Melastomataceae arrived from Africa in the Late Cretaceous. This study tests these hypotheses in a Bayesian framework, using three combined sequence datasets analysed under a relaxed clock and simultaneously calibrated with fossils, some not previously used. The new fossil calibration comes from a re-dated possibly Middle or Upper Eocene Brazilian fossil of Melastomeae. Tectonic events were also tentatively used as constraints because of concerns that some of the family's fossils are difficult to assign to nodes in the phylogeny. Regardless of how the data were calibrated, the estimated divergence times of Madagascan and Indian lineages were too young for Cretaceous explanations to hold. This was true even of the oldest ages within the 95% credibility interval around each estimate. Madagascar's Melastomeae appear to have arrived from Africa during the Miocene. Medinilla, with some 70 species in Madagascar and two in Africa, too, arrived during the Miocene, but from Asia. Gravesia, with 100 species in Madagascar and four in east and west Africa, also appears to date to the Miocene, but its monophyly has not been tested. The study afforded an opportunity to compare divergence time estimates obtained earlier with strict clocks and single calibrations, with estimates based on relaxed clocks and different multiple calibrations and taxon sampling.

Biomass allocation, growth, and photosynthesis of genotypes from native and introduced ranges of the tropical shrub Clidemia hirta.

We tested the hypothesis that the tropical shrub Clidemia hirta appears more shade tolerant and is more abundant in its introduced than native range because of genetic differences in resource acquisition, allocation, and phenotypic plasticity between native and introduced genotypes. We examined growth, biomass allocation, and photosynthetic parameters of C. hirta grown in a greenhouse from seed collected from four populations in part of its native range (Costa Rica) and four populations in part of its introduced range (Hawaiian Islands). Six-month-old seedlings were placed in high (10.3-13.9 mol m(-2) day(-1)) or low (1.4-4.5 mol m(-2) day(-1)) light treatments and grown for an additional 6 months. Our study provided little evidence that Hawaiian genotypes of C. hirta differed genetically from Costa Rican genotypes in ways that would contribute to differences in habitat distribution or abundance. Some of the genetic differences that were apparent, such as greater allocation to stems and leaf area relative to whole plant biomass in Costa Rican genotypes and greater allocation to roots in Hawaiian genotypes, were contrary to predictions that genotypes from the introduced range would allocate more biomass to growth and less to storage than those from the native range. Hawaiian and Costa Rican genotypes displayed no significant differences in relative growth rates, maximal photosynthetic rates, or specific leaf areas in either light treatment. In the high light environment, however, Hawaiian genotypes allocated more biomass to reproductive parts than Costa Rican genotypes. Phenotypic plasticity for only 1 of 12 morphological and photosynthetic variables was greater for Hawaiian than Costa Rican genotypes. We conclude that genetic shifts in resource use, resource allocation, or plasticity do not contribute to differences in habitat distribution and abundance between the native and introduced ranges of C. hirta.