Plant Species Research Articles

Intraspecific diversity of multiple plant species shows no change across an urbanization gradient

Intraspecific diversity of multiple plant species shows no change across an urbanization gradient

Temporal host–symbiont dynamics in community contexts: Impacts of host fitness and vertical transmission efficiency on symbiosis prevalence

Abstract Symbiotic associations play a role in plant ecology and evolution, but the outcome of the interaction depends on the life‐history traits of the partners and the environmental context. Although symbiosis with vertically transmitted microorganisms should result in mutualism, it is not clear how the transmission process aligns with the outcome of the context‐dependent symbiosis. For 3 years, we sampled individuals of an annual plant species that forms symbiosis with a vertically transmitted fungal endophyte, in paired stands of two contrasting vegetation communities (humid mesophytic meadows [HMM]: productive/low stress, and humid prairies [HP]: less productive/high stress). We estimated the prevalence of symbiosis at the population level, and the fitness of the plant, the symbiotic status and vertical transmission efficiency at the individual level. Over 3 years, the prevalence of symbiosis was ≈100% in HMM and ≈75% in HP. Plant fitness was very low and high in years with precipitation below and above the yearly mean, respectively. The higher fitness of endophyte‐symbiotic plants was evident in the HMM and high precipitation years. Vertical transmission of endophytes was higher in HMM (≈96%) compared to HP (≈93%) and was not related to plant fitness. Despite transmission inefficiencies in HP, changes in prevalence within the growing season (from seeds to the final plant stand) suggest a fitness advantage for symbiotic plants. Vertical transmission is expected to promote mutualism as it aligns partners' fitness. Although symbiotic plants showed higher fitness and the probability of transmission failures was higher among low‐fitness plants, the variation in transmission efficiency between plants and vegetation communities was not related to the fitness of the individual host. Our study provides evidence that context‐dependent vertical transmission efficiency and endophyte‐mediated fitness advantages interact complexly to determine the prevalence of symbiosis in populations that occur in contrasting vegetation communities. Read the free Plain Language Summary for this article on the Journal blog.

Gastroprotective Efficacy of North African Medicinal Plants: A Review on Their Therapeutic Potential for Peptic Ulcers

ABSTRACTPeptic ulcer disease remains a prevalent gastrointestinal disorder worldwide. Current treatments often have limitations, sparking interest in alternative therapies from medicinal plants. This review examines the gastroprotective potential of 54 North African medicinal plants against peptic ulcers. An extensive literature search was conducted, focusing on plants with preclinical and clinical evidence of anti‐ulcer efficacy and documented use in North African traditional medicine. The review identified several promising plant species, such as licorice (Glycyrrhiza glabra), chamomile (Matricaria chamomilla), olive (Olea europaea), pomegranate (Punica granatum), Aloe vera, and black seed (Nigella sativa), along with their bioactive constituents, including flavonoids, tannins, and terpenoids. These compounds exhibit gastroprotective properties through multiple mechanisms, such as enhancing the gastric mucosal barrier, inhibiting acid secretion, displaying antioxidant and anti‐inflammatory effects, promoting ulcer healing, and combating Helicobacter pylori infection. The evidence presented includes in vitro assays, animal models, and some clinical studies. While many of the 53 plants reviewed demonstrated significant anti‐ulcer effects compared to standard drugs, further clinical research is needed to establish efficacy and safety in humans. The synergistic actions of phytochemical mixtures in medicinal plant extracts likely contribute to their therapeutic potential. This review highlights the role these North African medicinal plants may play in the prevention and treatment of peptic ulcers and identifies promising candidates for further research and development of evidence‐based botanical therapies.

Genome-Wide Identification and Expression Analysis of the REF Genes in 17 Species

Natural rubber production currently relies heavily on a single species, Hevea brasiliensis, underscoring the urgent need to identify alternative sources to alleviate the strain on natural rubber production. The rubber elongation factor (REF) and small rubber particle protein (SRPP), both members of the REF/SRPP gene family, are crucial for natural rubber biosynthesis. However, research on the REF gene has predominantly focused on H. brasiliensis and Taraxacum kok-saghyz. We conducted a comprehensive genome-wide identification and characterization of the REF gene, identifying 87 REF protein sequences across 17 plants species. We observed a significant increase in the copy numbers and expression of REF genes in rubber-producing plants. Notably, in H. brasiliensis, T. kok-saghyz, Eucommia ulmoides, Lactuca sativa, and other rubber-yielding species, the number of REF genes has markedly increased. Furthermore, some REF genes in H. brasiliensis form a distinct clade in phylogenetic analyses and exhibit differences in conserved motif arrangements and tertiary protein structures compared to other REF genes. These findings suggest that REF genes in rubber-producing plants may have undergone independent evolution, leading to changes in copy number and structure. These alterations could contribute to the production of natural rubber in these species. The results of this study provide a scientific basis for further research into the mechanisms of rubber production in plants and for identifying potential rubber-producing species.

Nanomaterial-Based Biofortification: Potential Benefits and Impacts of Crops.

Nanomaterials (NMs) have shown relevant impacts in crop protection, improvement of yields, and minimizing collateral side effects of fertilizer and pesticides in vegetable and fruit production. The application of NMs to improve biofortification has gained much attention in the last five years, offering a hopeful and optimistic outlook. Thus, we propose comprehensively revising the scientific literature about the use of NMs in the agronomic biofortification of crops and analyzing the beneficial impact of the use of NMs. The results indicated that different species of plants were biofortified with essential elements and macronutrients after the applications of Zn, Fe, Se, nanocomposites, and metalloid NPs. In addition, the physiological performances, antioxidant compounds, and yields were improved with NMs. Using nanofertilizers for the biofortification of crops can be considered a promising method to deliver micronutrients for plants with beneficial impacts on human health, the environment, and agriculture.

Harnessing the power of rhizosphere bacteria for pollution remediation: strategies, mechanisms, and environmental impact: A review

This review explores into the sizeable potential of rhizosphere bacteria as effective mediators in the pollution remediation. These rhizosphere bacteria are primarily found in the soil surrounding plant roots, and they have an extremely strong ability to remove a wide range of toxins from the environment. This is attuned with the idea of phytoremediation, which is the use of plants to clean adulterated soil or water. In addition to vigorous participation in bioremediation processes, their diverse activities include stimulating plant growth and serving as biocontrol agents against plant diseases. Their ability to gather, change, and restrain pollutants is one of their main advantages, especially when used in combination with phytoremediation techniques. To fully utilize these microorganisms, it is essential to understand the various bacterial strains and their complex biological pathways that influence their behavior. The diversity and richness of rhizosphere bacterial populations, significantly affected by different plant species and environmental factors, is a crucial area that requires further study. Grasping this heterogeneity is essential for adapting phytoremediation strategies to particular contamination situations and exploiting their effectiveness. Rhizosphere microorganisms present a feasible path towards a more supportable and clean future. This might potentially make a big contribution to environmental restoration efforts in a world that is always changing.

Segetal plants of agricultural landscapes of the Southern Non‐Chernozem zone as a source of biological resources

Aim. To identify economically significant species of segetal plants of agrophytocenoses in the Southern Non‐Chernozem zone and assess their dynamics with changes in anthropogenic load.The study was carried out by analysing geobotanical descriptions of agrophytocenoses in the Southern Non‐Chernozem Zone. The species diversity of economically important species was established during the period of extensive farming (1929–1933), the beginning of intensification (1936–1938), a high level of intensification (1981–1983), and a period of decreasing intensity of farming (2012–2022).At all stages of the study, groups of forage, medicinal and honey plants were round to have a high species diversity. The presence of individual representatives of vegetable, vitamin, insecticidal and ornamental species in agrophytocenoses was established.Changes in the nature and degree of anthropogenic pressure on agrophytocenoses has led to a significant transformation of species composition and abundance of representatives of economically significant groups. The smallest number of these was noted in the 1980s. Currently, species diversity has increased due to a decrease in the intensity of agriculture in the region.

Biochemical Changes and Germination Response of Indian Sandalwood (Santalum album L.) Seeds Subjected to Biopriming Techniques and Variable Post-priming Storage

Understanding of the storage behaviour of endangered plant species such as Indian Sandalwood, Santalum album L. is important for successful conservation. We tested biopriming method with five biopriming agents (e.g. Effective microorganisms; Plant growth promoting rhizobacteria (PGPR-I and PGPR-II); Pseudomonas fluorescens and Piriformospora indica) with four uniform durations of treatments viz. 2, 4, 6 and 8 days. Hydropriming was also performed with similar condition for comparison of seed performance. The study examined the biochemical changes that occur in Sandalwood seeds during different post-priming storage periods (0, 30, 60, 90 days) to assess the efficacy of biopriming techniques on seed germination and health. Biopriming with Pseudomonas fluorescens for eight days recorded the highest germination percentage (70.67%) and the highest germination rate index (0.84). Longer durations of PGPR-I and Piriformospora indica treatment (6-8 days) lowered the imbibition period and mean germination time while increasing the germination rate. After a post-priming storage period of 30 days, only EM and Pseudomonas fluorescens treated seeds germinated while all other treatments failed to germinate. Absence of germination in any biopriming group at 60 and 90 days storage period indicated that the sandal seeds deteriorated over extended storage period. The reduction in seed viability of sandal seeds was consequent to the changes in the biochemical characteristics and action of enzymes (α and β amylases) involved in seed food reserve depletion and loss in membrane integrity.

Endophytic bacteria in Camellia reticulata pedicels: isolation, screening and analysis of antagonistic activity against nectar yeasts

Camellia reticulata, an ancient plant species endemic to Yunnan Province, China, remains underexplored in terms of its endophytic bacterial communities. The plant tissue pedicel serves as the connection between the flower and the stem, not only delivers nutrients but also transmits metabolic substances from endophytic bacteria to the nectar during long-term microbial colonization and probably improves the antagonistic activity of nectar against yeast. Hence, 138 isolates of endophytic bacteria have been isolated in this study from the pedicels of 12- and 60-year-old C. reticulata. Comparative analysis revealed significantly higher density of endophytic bacteria in older trees. Among these isolates, 29 exhibited inhibitory effects against nectar yeasts. Most of the isolates displayed positive results for Gram staining, catalase reaction, gelatin liquefaction, and motility. Additionally, the isolates demonstrated the ability to utilize diverse substrates, such as glucose, nitrate, and starch. Based on 16S rRNA molecular biology analysis, these isolates were identified to be 11 different species of 6 genera, with the majority belonging to Bacillus genus. Notably, C1 isolate, identified as Bacillus spizizenii, exhibited strongest antagonistic effect against three yeasts, i.e., Metschnikowia reukaufii, Cryptococcus laurentii, and Rhodotorula glutinis, with minimum inhibitory concentration values below 250 μg/mL. Major metabolites of B. spizizenii were aminoglycosides, beta-lactams, and quinolones, which possess antimicrobial activities. Furthermore, KEGG enrichment pathways primarily included the synthesis of plant secondary metabolites, phenylpropanoids, amino acids, alkaloids, flavonoids, neomycin, kanamycin, and gentamicin. Therefore, antagonistic activity of B. spizizenii against yeasts could be attributed to these antibiotics. The findings highlight the diverse endophytic bacteria associated with C. reticulata, indicating their potential as a valuable resource of bioactive metabolites. Additionally, this study provides new insights into the role of endophytic bacteria of pedicels in enhancing nectar resistance against yeasts.

The intermorph breeding system is responsible for reproductive success in heterostylous Nyctanthes arbor‐tristis L.

AbstractHeterostyly is a specialized reproductive system associated with self‐ and intramorph incompatibility. It reinforces the intermorph breeding system in heterostylous plant species. However, distyly has not been comprehensively studied in Nyctanthes arbor‐tristis. The present study demonstrates the floral traits, breeding system, fruit and seed set, and morph ratio in distylous N. arbor‐tristis. The length of style and filament showed reciprocal herkogamy between long style (L‐morph) and short style (S‐morph). Flower size, corolla tube size, stamen and anther length, ovary length, and pollen diameter were larger in S‐morph. However, the style was longer in L‐morph. Our results demonstrated strongly incompatible self‐ and intramorph pollination combinations. The intermorph pollination was compatible, showing normal pollen tube growth throughout the style and ovary. The embryo formation was also higher in intermorph interaction. Moreover, the fruit setting was higher when the intermorph plants grew in the vicinity of natural conditions. Collectively, all data indicate that N. arbor‐tristis is a distylous species with a self‐incompatible breeding system, resulting in less seed formation in nature.

The Inhibitory Tendency of Calamagrostis epigejos and Solidago spp. Depends on the Successional Stage in Postindustrial Vegetation

ABSTRACTIn spontaneously vegetated postindustrial areas, we have limited knowledge of whether the known inhibitory tendencies of herbaceous species—Calamagrostis epigejos and Solidago spp.—vary across successional stages. Our study fills this knowledge gap to assess the inhibitory role of the invasive alien and expansive native species with known behavior from the literature. Specifically, we hypothesized: (i) there will be an inhibitory effect of these species on diversity across successional classes; (ii) the effect of a species will depend on the successional class due to abiotic requirements of plant communities in each successional class. We recorded vascular plant species and their abundance across 400 plots on post‐coal mine heaps in Upper Silesia, Poland. We classified spoil heaps into three successional classes (early‐stage; mid‐stage; late‐stage). We calculated plant community taxonomic, functional, and phylogenetic diversity and, using generalized linear mixed‐effects models, we estimated predictors of diversity indices across successional classes. While we found no limiting effects of these species on diversity indices across successional classes, the effects of a species depended on the successional stage. We found the impacts of Calamagrostis and Solidago cover on diversity indices in the mid‐successional stage. This implies that the early‐successional stage is controlled by the lottery (random) model of community assembly. However, in the mid‐successional stage, the competitive exploitation mechanism is evident, resulting in declines in diversity indices. Thus, the impacts of Calamagrostis and Solidago on diversity indices are evident in the mid‐successional stage.

Efficient Storage and Analysis of Genomic Data: A k-mer Frequency Mapping and Image Representation Method.

k-mer frequencies are crucial for understanding DNA sequence patterns and structure, with applications in motif discovery, genome classification, and short read assembly. However, the exponential increase in the dimension of frequency tables with increasing k-mer length poses storage challenges. In this study, we present a novel method for compressing k-mer data without information loss, aiming to optimize storage and analysis processes. We employed Chaos Game Representation (CGR) to map k-mers to coordinates and used these components to generate raster images of k-mers. The CGR maps were partitioned and labeled based on substrings, with each substring mapped to a subframe, creating a fractal-like structure. The entire k-mer frequency set of each genomic sequence was represented as a single image, with each pixel corresponding to a specific k-mer and its occurrence. This approach reduced file size by up to 16-fold compared to plain text and 3-fold compared to binary format. Furthermore, we demonstrated the feasibility of performing alignment-free similarity analyses on images derived from k-mer frequencies of whole genome sequences from 14 plant species. Our results highlight the potential of this method as a fast and efficient tool for accessing, processing, and analyzing large biological sequence datasets, enabling the retrieval of k-mer frequencies and image reconstruction.

Montane grassland recovery: lessons from 25 years of the Working for Water program on the northern Drakensberg Escarpment, South Africa

Despite their strategic importance as biodiversity hotspots and water sources, montane ecosystems are among the most neglected conservation areas. In particular, the monitoring and management of invasive alien plants in this critical biome is limited. This study presents an analysis of long‐term invasive alien plant removal within montane grassland ecosystems, drawing on insights from 25 years of the Working for Water (WfW) program on the northern Drakensberg Escarpment. We assessed the response of vegetation communities to invasive alien plant removal in this region. Using data from the WfW program on clearance activities, expenditure, and re‐visit times, we compared plant species richness, diversity, and composition in sites managed under the WfW program to adjacent patches of pristine vegetation. Results showed minimal variation in species richness between cleared sites and unmanaged sites. However, these vegetation communities remain distinctly dissimilar across sites. These findings suggest the need for active restoration of montane vegetation communities if they are to return to their natural condition and further highlight the need to conserve the remaining habitats for critically endangered species, even in their depauperate state.

Assessing the distribution of soil organic carbon under three plant species across coastal sabkhas: A comparative analysis

Assessing the distribution of soil organic carbon under three plant species across coastal sabkhas: A comparative analysis

Agricultural legacy shapes plant diversity patterns in mountain grasslands of Maramureș and Bukovina: A cross‐border perspective (Ukraine, Romania)

Abstract We investigated farming practices and grassland plant diversity patterns in the historical regions of Maramureș and Bukovina, located in the central Eastern Carpathians of Romania and Ukraine. We explored the influence of social and historical factors on recent grassland plant diversity, including changes and modifications in land use and grassland management practices. We used stratified random sampling to select 48 grassland parcels in eight villages on the Ukrainian‐Romanian borderlands. We identified the factors that affect the composition and diversity of grassland vascular plants and bryophytes at multiple spatial scales and compared the frequency and timing of historical and recent grassland management practices to distinguish between preserved and modified agricultural traditions. In most of the grassland parcels studied (83% in Romania and 78% in Ukraine), traditional land use persisted. Local plant species richness was primarily influenced by management practices, outweighing the impact of topography and soil factors. Regular mowing at appropriate intensity increased the richness of vascular plants, while grazing promoted the richness of bryophyte species. Modifications to farming systems, observed in all studied villages, were mainly due to declining population and livestock numbers. Although the timing of spring and autumn grazing in hay meadows still adhered to tradition, mowing schedules shifted earlier, especially for the first cut of two‐cut hay meadows. Traditional corralling, fertilization and hayseed application have become rare or discontinued in certain villages, while controlled burning has increased. Past use of mineral fertilizers in Ukrainian villages during the Soviet era influenced the recent diversity and composition of vascular plant species, favouring nutrient‐demanding species. Social factors and agricultural policies indirectly affect biodiversity in semi‐natural grasslands, leaving a tangible footprint even in the most remote areas of the Carpathian Mountains. We provide basic recommendations to preserve the remarkable biodiversity of the region. Read the free Plain Language Summary for this article on the Journal blog.

Findings of Aquatic Vascular Plants on the Sakhalin Island

Investigations of South-western geobotanical district of Sakhalin Island, which is classified as a separate subzone of dark coniferous forests with an admixture of broad-leaved species and corresponds to Krillon floristic district, revealed a number of new aquatic vascular plant species for that area (Lemna turionifera, Myriophyllum verticillatum, Potamogeton gramineus, P. manchuriensis, Stuckenia pectinata, Utricularia minor, U. × ochroleuca). There is also a novelty for the South-Sakhalin lowland geobotanical district (Myriophyllum spicatum). All these taxa are known from other geobotanical districts of Sakhalin. The additions to the flora of the South-western district, which is well surveyed by botanists, indicate not floristic uniqueness of the subzone of dark coniferous forests with an admixture of broad-leaved species, but rather a poor knowledge of the Sakhalin Island aquatic flora.

Chilling and Forcing Requirements of Wintersweet (Chimonanthus praecox L.) Flowering in China

Numerous studies have reported phenological changes and their driving mechanisms in spring flowering plants. However, there is little research on the shifts of winter flowering phenology and its response to forcing and chilling requirements. Based on the China Phenological Observation Network (CPON) ground observation data from nine sites over the past 20 years, we explored the spatial and temporal variation patterns of flowering plants and their response to chilling and forcing in wintersweet (Chimonanthus praecox L.), a common winter flowering plant species in temperate and subtropical zones of China. We used three chilling models (chilling hour, Utah, and dynamic models) and the growing degree hours (GDHs) model to calculate each site’s daily chilling and forcing. Using the partial least squares (PLSs) regression approach, we established the relationship between the first flowering date (FFD) and pre-season chilling and forcing in wintersweet, based on which we identified chilling and forcing periods and calculated chilling and forcing requirements. This study found that the FFD of wintersweet in China showed an overall advancement trend during the last 20 years. Still, there were temporal and spatial differences in the FFD of wintersweet among different sites. The PLS results showed that wintersweet also had periods of chilling and forcing, both of which co-regulated wintersweet flowering. We found the forcing and chilling requirements of wintersweet varied significantly from site to site. The higher the latitude is, the more chilling requirements are needed. The chilling requirements for wintersweet were about 6.9–34.9 Chill Portions (CPs) and 1.4–21.6 CP in the temperate and subtropical zones, respectively, with corresponding forcing requirements of 3.2–1922.9 GDH and 965.3–8482.6 GDH, respectively. In addition, we found that the temperature requirements of wintersweet were correlated by a negative exponential relationship, suggesting that chilling and forcing requirements have an antagonistic effect on initiating flowering phenology. Our results could help us understand how flowering dates of winter flowering plants respond to climate change.

Arsenic and Heavy Metals in Soils and Plants near Sulfide Mines: Implications for Phytoremediation and Phytomanagement.

The accumulation of heavy metals (i.e., As, Cu, Ni, Pb, and Zn) in soils and native plant species near copper, nickel, and pyrite mines in Vietnam was assessed. The highest soil As, Cu, Ni, Pb, and Zn concentrations recorded in mine soils were 42.3, 1570, 9870, 128, and 462 mg/kg, and those in agricultural soils were 11.4, 453, 94.9, 34.4, and 147 mg/kg, respectively. Pollution index (PI) values indicated heavy pollution (PI = 3.99-13.0) for mine soils, and unpolluted to severely polluted (PI = 0.65-2.84) for agricultural soils. Soil enrichment factors had a wide range, from minimal to extreme enrichment of heavy metals (EF = 0.03-91.4). Arsenic minerals may be the main source of high As concentrations in sulfide mines. The As, Cu, Ni, Pb, and Zn concentrations of 20 native plant species near three mines were in the ranges of 0.05-1150, 3.17-123, 0.47-291, 0.08-6.34, and 6.87-168 mg/kg (dry weight, DW), respectively. Based on the recorded hyperaccumulation levels (1150 mg/kg, DW), bioaccumulation factors (BAF = 2.4-90.0), biomass, and rapid growth, Pteris vittata L. is considered a promising plant for phytoextraction of As in soils. Bidens pilosa L. has potential for phytostabilization of sulfide-bearing soils, given its low concentrations of heavy metals in plant shoots, BAF values of <1, high biomass, and wide distribution. Integrated phytoremediation and phytomanagement are applicable to metal-contaminated soils. Phytomining, energy crops, and vegetation cover should be investigated for the phytomanagement of metal-contaminated soils in mining areas.

Plant Diversity Research in Shangqiu Yellow River Ancient Course National Forest Park, China

The Shangqiu Yellow River Ancient Course National Forest Park, the only national forest park in China created entirely from man-made forests, plays a critical role in ecological conservation. Our research employed plot surveys and quantitative ecological methods, including a diversity index analysis and importance value analysis, to investigate the diversity of arboreal, shrub, and herbaceous plants. This study revealed the composition and distribution of plant communities and analyzed invasive species. It identified dominant plant families, genera, and species and evaluated the types, distribution, and characteristics of invasive plants. We documented 70 families, 177 genera, and 254 species, highlighting that local environmental factors and human activities significantly affect the composition and distribution of plant communities. The presence of 29 invasive plant species poses a risk to the ecosystem. We constructed a phylogenetic tree of the plant community based on rbcL (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit) gene sequences, revealing the evolutionary relationships among species, and evaluated the community’s stability using the NTI (nearest taxon index) and NRI (net relatedness index). This research aims to provide a scientific foundation for conserving plant diversity and promoting sustainable development, and it can inform ecological protection and biodiversity studies in similar regions.

Air pollution tolerance and metal accumulation potential of some plant species growing in educational institutions of Amritsar, India.

Poor air quality in urban areas increases the exposure of individuals to air pollutants. Hence, it becomes mandatory to grow such plant species that have more potential to tolerate air pollution and can aid in its mitigation. Air pollution tolerance index (APTI) and anticipated performance index (API) are two indices that help in scientific evaluation of plant species before recommending them for plantation. In this study, six plant species from three educational institutions of Amritsar city were screened for their tolerance and performance against air pollution as well as for their capability to act as accumulators of nine metals viz., aluminium (Al), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). On the basis of APTI, Cassia fistula (C. fistula) was categorized as a tolerant species while Alstonia scholaris (A. scholaris), Cascabela thevetia (C. thevetia), Monoon longifolium (M. longifolium), Pongamia pinnata (P. pinnata) and Syzygium cumini (S. cumini) were categorized as intermediately tolerant plant species. API results suggested that A. scholaris, C. fistula, M. longifolium, P. pinnata and S. cumini should be planted for air pollution mitigation. Geo-accumulation Index (Igeo) results showed that soil samples were moderately contaminated with three (Pb, Cu and Zn) metals. Bioaccumulation factor (BAF), for all metals among six plant species, was found to be less than one implying that these plants were absorbers of metals. Metal Accumulation Index (MAI) indicated that C. thevetia, C. fistula and P. pinnata exhibited relatively higher potential for metal accumulation.