Small Trees Research Articles

Pinus mugo Turra and its Therapeutic Potential: A Narrative Review

Pinus mugo Turra is a coniferous species of shrub or small tree typical of central and south-eastern Europe. It is commonly called mugo pine, mountain pine, or dwarf mountain pine referring to its habit and small size. Indeed, this plant lives at higher altitude above 1400 m above the see level where it deals with harsh conditions typical of high mountain. From an ethnotraditional point of view, P. mugo is mainly used for respiratory disorders and wound healing. In particular, its essential oils have been shown to possess interesting antimicrobial and antioxidant activities, which can substantiate its potential therapeutic effect in pulmonary and urinary tract diseases, as well as antinflammatory and antitumor effects. This review also offers a summary on the chemical constituents of P. mugo that contribute to its therapeutic potential.

The medicinal plant Buddleja asiatica and its relation to the welfare of local people in the Pan‐Himalayan region: Past, present, and future perspectives

Societal Impact StatementGlobalization and rapid shifts in culture and economy threaten indigenous and local knowledge (ILK) systems, and large intergenerational gaps in this knowledge already exist. Buddleja asiatica is a deciduous shrub or small tree with traditional medicinal applications but is currently largely overlooked as a medicinal resource. This study investigates the traditional uses of B. asiatica in indigenous communities in the Pan‐Himalayan region through ethnobotanical field surveys, with a view to preserving cultural heritage and strengthening economic resilience in these communities, as well as developing B. asiatica as a medicinal resource. Prioritizing the well‐being of mountain communities, this study aims to bridge community development with nature.SummaryBuddleja asiatica Lour. (Scrophulariaceae) is widely distributed across the Pan‐Himalayan region. It has traditional medicinal applications and cultural value, as well as ecological significance. We conducted an ethnobotanical study combining field surveys from Nepal and Xizang, China with a literature review using Web of Science (WoS) to review the ethnobotanical, phytochemical, and pharmacological aspects of this species. Our study highlights the cultural significance of B. asiatica within indigenous communities and, in particular, the use of the leaves to make a starter culture for the preparation of wine. However, an evident intergenerational gap in knowledge transfer exists. The phytochemical investigation revealed the presence of various chemical classes (carbohydrates, terpenoids, flavonoids, saponins, esters, steroids, glycosides, and fatty acids), of which 15 phytoconstituents were first reported from various parts of B. asiatica. The potential medicinal properties of these chemicals include anti‐inflammatory, antioxidant, cytotoxic, antihepatotoxic, antimicrobial, and cholinesterase activities. We combine these lines of evidence to show the prospects for the livelihoods of local people across this region and propose future research directions.

Exploring Juniperus phoenicea L extract through phytochemical analysis, anti-lipase effects, and comprehensive molecular studies

Lipase inhibitors are used in the treatment of candidiasis, obesity, and acne problems. Therefore, the investigation of new natural lipase inhibitors has generated great interest. Juniperus phoenicea is a small Mediterranean tree considered an important medicinal plant. Through this work, we investigated the composition and inhibition effect of J. phoenicea extract on Candida rugosa and human lipases; and we analyzed the interactions between detected compounds and lipases using molecular docking, ADME-T, and dynamic studies. We extracted the secondary metabolites from the plant aerial parts and tested their activities against lipase. We examined major components of J. phoenicea, using Autodock vina for molecular docking, Desmond from Schrodinger suite 2021–1 for dynamics, and evaluating its drug-likeness and toxicity properties using ADMET webserver. We found that the IC50 values of ethyl acetate and methanol extracts are 1.33±0.10 and 1.731 mg/mL. Using HPLC quantitative analysis we identified in ethyl acetate extract the following phenolic compounds gallic acid, rutin, apigenin-7-O-glucoside, cinnamic acid, and quercetin. The complex apigenin-7-O-glucoside-lipase is stabilized by four hydrogen bonds and hydrophobic interactions, and the binding energy equals -10 Kcal/mol, which is better than the interactions saved for orlistat. Dynamic Simulation demonstrated better stability in the ligand-protein complex apigenin-7-O-glucoside-1lpb within 100 ns than the orlistat-1lpb complex. This study is described in this work for the first time. The results indicated that apigenin-7-O-glucoside from J. phoenicea L could be a good choice to develop a new drug candidate against candidiasis, obesity, and other lipase-related diseases.

The cooling effect of trees in high-rise building complexes in relation to spatial distance from buildings

Street trees are vital in mitigating urban heat islands, with their cooling effect significantly influenced by the urban layout. Past studies explored how urban canyon characteristics—aspect ratio, building coverage—affect tree cooling, yet seldom analyzed the impact of distance between trees and buildings. Addressing this, our study evaluates tree cooling effects concerning their proximity to shaded and sunlit walls. The findings highlight that cooling effectiveness varies with the ratio of distance from the shaded wall to building height (Dsha:H), peaking within a ratio range of 0.55 to 0.7. Below a ratio of 0.3, effectiveness decreases to 9–29 %, emphasizing the importance of strategic planting distances. The result shows that when planted at an optimal distance from buildings, small trees can produce similar radiation mitigation effects to those of larger trees. This discovery advocates for thoughtful tree placement in high-density areas, optimally leveraging their shade and evapotranspiration benefits. The study provides actionable insights for urban planners and landscape architects, suggesting that careful consideration of tree placement relative to building shadows can significantly improve urban climates, offering a strategic approach to deploying green infrastructure in high-rise complexes for enhanced climate resilience.

Chromosome-level genome assembly and annotation of Flueggea virosa (Phyllanthaceae)

Flueggea virosa (Roxb. ex Willd.) Royle, an evergreen shrub and small tree in the Phyllanthaceae family, holds significant potential in garden landscaping and pharmacological applications. However, the lack of genomic data has hindered further scientific understanding of its horticultural and medicinal values. In this study, we have assembled a haplotype-resolved genome of F. virosa for the first time. The two haploid genomes, named haplotype A genome and haplotype B genome, are 487.33 Mb and 477.53 Mb in size, respectively, with contig N50 lengths of 31.45 Mb and 32.81 Mb. More than 99% of the assembled sequences were anchored to 13 pairs of pseudo-chromosomes. Furthermore, 21,587 and 21,533 protein-coding genes were predicted in haplotype A and haplotype B genomes, respectively. The availability of this chromosome-level genome fills the gap in genomic data for F. virosa and provides valuable resources for molecular studies of this species, supporting future research on speciation, functional genomics, and comparative genomics within the Phyllanthaceae family.

Chemical Analysis of Pomegranate Flower Essential Oil in Türkiye

Punica granatum L. (Pomegranate) grows naturally in a wide area from northwest Türkiye to western and northern Pakistan and is also cultivated throughout subtropical and tropical regions of the world. Pomegranate is in the form of a spiny shrub or a small tree. The barks, fruit peels, flowers, and seeds of the plant are used in traditional medicine due to their ellagitannin and polyphenol content and are used to treat circulatory system disorders. In this study, essential oil (EO) of P. granatum flowers was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. As a result, the chemical composition of the essential oil obtained was elucidated. As a result, nine compounds representing 99.9% of the essential oil of P. granatum flowers were characterized, with hexadecanoic acid (52.4%), linoleic acid (15.2%), heptacosane (10.1%), and pentacosane (10.1%) as the major components. Notably, this research marks the first comprehensive examination of the essential oil of pomegranate flowers in Türkiye.

Anti-seasonal flooding drives substantial alterations in riparian plant diversity and niche characteristics in a unique hydro-fluctuation zone.

Human-induced disturbances such as dam construction and regulation have led to widespread alterations in hydrological processes and thus substantially influence plant characteristics in the hydro-fluctuation zones (HFZs). To reveal utilization of limited resources and mechanisms of inter-specific competition and species co-existence of plant communities based on niche breadth and overlap under the different HFZs of the Three Gorges Reservoir (TGR) in China, we conducted a field investigation with 368 quadrats on the effects of hydrological alterations on plant diversity and niche characteristics. The results showed anti-seasonal flooding precipitated the gradual disappearance of the original diverse niches, resulting in the reduction of plant species richness and functional diversity and more obvious competition among plant species with similar resource requirements. Annuals, perennials and shrubs accounted for 71.23%, 27.39% and 1.37%, respectively, suggesting that annuals and flood-tolerant riparian herbs were favored under such novel flooding conditions. A consistent increase in species number, Shannon-Wiener diversity index and Simpson dominance index with altitude was inconsistent with hump-shaped diversity-disturbance relationship of the intermediate disturbance hypothesis, while the opposite trend was observed for the Pielou evenness index. This species distribution pattern might be caused by several synergetic attributes (e.g., the submergence depth, plant tolerant capacity to flooding, life form, dispersal mode and inter-specific competition). Vegetation types shifted from xerophytes to mesophytes and eventually to hygrophytes with the increasing flooding time in the HFZs. Hydrological alterations proved to be the paramount driver of vegetation distribution in the different HFZs. The niche analysis provided the first insights on the mechanisms of resource utilization and inter-specific competition, of which annuals could germinate quickly after soil drainage to achieve the greatest competitive advantages and occupy a larger niche space than other plants. Vegetation was still in the early stage of primary succession in the novel riparian forests. Therefore, vegetation restoration strategies should be biased towards herbaceous plants, due to annuals with better environmental adaptability, supplemented by shrubs and small trees. To establish a complete reference system for vegetation restoration, natural vegetation monitory plots in the different succession stages should be established in the different HFZs of the TGR, and their environmental conditions, community structures and inter-specific relationships further analyzed.

Sexual dimorphism and pollination mechanism of Zanthoxylum armatum, a vulnerable medicinally important dioecious tree

Among dioecious species, the differential strategy of resource allocation between male and female plants is depicted in their life-history traits and reproductive features. This is classified as sexual dimorphism. The strategies of resource allocation along with the habitat of these species pose an impact on their pollination mechanism and reproductive success. Zanthoxylum armatum DC (Rutaceae) is a small tree with wide economic and medicinal value. The species is naturally distributed in tropical parts of India and other countries. Due to overexploitation of natural populations in India, the species is rapidly declining. To restore the population of the species in the wild and establish commercial plantations, detailed knowledge of its reproductive biology is essential. Thus, the present study was conducted in natural population of Z. armatum growing in the union territory of Jammu and Kashmir, India. The study revealed sex-biased allocation and sexual dimorphism both in vegetative and reproductive traits. Such traits include more height and higher number of shoots, inflorescences, and flowers in male plants than in female plants. The natural populations of Z. armatum exhibit a male-biased sex ratio, and such biasness appears to be the outcome of resource allocation strategies and other demographic characteristics. Species possibly exhibit presence of ambophilous suite, i.e., a combination of wind and insect pollination in floral features. However, pollen dispersal by wind is up to limited distance, and thus wind may or may not be effective in fruit-set.

Phylogenomics of the pantropical Connaraceae: revised infrafamilial classification and the evolution of heterostyly

Connaraceae is a pantropical family of about 200 species containing lianas and small trees with remarkably diverse floral polymorphisms, including distyly, tristyly, homostyly, and dioecy. To date, relationships within the family have not been investigated using a targeted molecular phylogenetic treatment, severely limiting systematic understanding and reconstruction of trait evolution. Accordingly, their last infrafamilial classification was based only on morphological data. Here, we used phylogenomic data obtained using the Angiosperms353 nuclear target sequence capture probes, sampling all tribes and almost all genera, entirely from herbarium specimens, to revise infrafamilial classification and investigate the evolution of heterostyly. The backbone of the resulting molecular phylogenetic tree is almost entirely resolved. Connaraceae consists of two clades, one containing only the African genus Manotes (4 or 5 species), which we newly recognize at the subfamily level. Vegetative and reproductive synapomorphies are proposed for Manotoideae. Within Connaroideae, Connareae is expanded to include the former Jollydoreae. The backbone of Cnestideae, which contains more than half of the Connaraceae species, remains incompletely resolved. Reconstructions of reproductive system evolution are presented that tentatively support tristyly as the ancestral state for the family, with multiple parallel losses, in agreement with previous hypotheses, plus possible re-gains. However, the great diversity of stylar polymorphisms and their phylogenetic lability preclude a definitive answer. Overall, this study reinforces the usefulness of herbarium phylogenomics, and unlocks the reproductive diversity of Connaraceae as a model system for the evolution of complex biological phenomena.

First report of leaf spot disease caused by Pseudopithomyces chartarum on Lonicera caerulea L. in Heilongjiang Province, China.

Blue honeysuckle (Lonicera caerulea L.) cultivation has gradually expanded in China but continues to be limited by challenges such as leaf spot disease. Between September 2022 and September 2023, a leaf spot disease was observed on approximately 30% of 'Lanjingling' blue honeysuckles grown in a 2.66 ha field (a total of about 11,000 plants) in Jiamusi city (130.47°E, 46.16°N), Heilongjiang Province, China. Affected plants displayed brown necrotic lesions on their leaves that gradually expanded in area until the leaves fell off the plant entirely. Small, 3 to 4 mm segments of infected tissue from 50 randomly selected leaves were surface sterilized with 75% ethanol for 30 s and 5% sodium hypochlorite (NaOCl) for 3 min, rinsed three times with sterile distilled water, dried on paper towels, and plated in 9 cm Petri dishes containing potato dextrose agar (PDA) (Yan et al. 2022). Five pathogens (LD-232, LD-233, LD-234, LD-235, and LD-236) were isolated on PDA and displayed a conidia morphology consistent with Pseudopithomyces spp. (Perelló et al. 2017). The fungal colonies on PDA were villiform, white, and whorled and had sparse aerial mycelium on the surface with black conidiomata. The conidia were obpyriform and dark brown, had 0 to 3 transverse and 0 to 1 longitudinal septa, and measured 9.00 to 15.30 μm × 5.70 to 9.30 μm in size (n = 50). Genomic DNA was extracted from a representative isolate, LD-232, for molecular verification and PCR amplification was performed with ITS1/ITS4 (White et al. 1990), LROR/LR7 (Carbone and Kohn 1999), and RPB2-5F2/RPB2-7CR (Liu et al. 1999) primers. Sequences of LD-232 ITS (OR835654), LSU (OR835652), and RPB2 (OR859769) revealed 99.8% (530/531 nt), 98.8% (639/647 nt), and 99.8% (1015/1017 nt) shared identity with Pseudopithomyces chartarum sequences (OP269600, OP237014, and MK434892), respectively (Wu et al. 2023). Bayesian inference (BI) was used to construct the phylogenies using Mr. Bayes v. 3.2.7 to confirm the identity of the isolates (Ariyawansa et al. 2015). Phylogenetic trees cannot be constructed based on the genes' concatenated sequences because selective strains do not have complete rDNA-ITS, LSU, and RPB2 sequences. Therefore, based on the morphological characteristics and molecular phylogeny, LD-232 was identified as P. chartarum (Perelló et al. 2017; Wu et al. 2023). A pathogenicity test was performed with six healthy, two-year-old 'Lanjingling' blue honeysuckle plants. Three plants were inoculated by spraying the LD-232 conidial suspension (1 × 106 spores/ml) or clean water as an experimental control condition (Wu et al. 2023; Yan et al. 2023). All plants were cultured in a greenhouse at 28℃ under a 12-h light/dark cycle, and each experiment was replicated three times. Typical leaf spot symptoms were observed on inoculated leaves after 10 days. The same pathogens were reisolated from infected leaves, displayed the same morphological and molecular traits, and were again identified as P. chartarum, confirming Koch's postulate. P. chartarum previously caused leaf spot disease on Tetrapanax papyrifer in China (Wu et al. 2023). To our knowledge, this is the first report of blue honeysuckle leaf spot caused by P. chartarum in China. Identification of P. chartarum as a disease agent on blue honeysuckle will help guide future management of leaf diseases for this economically important small fruit tree.

The dynamics of deciduous dipterocarp forest in relation to climate variability in the Sakaerat Biosphere Reserve, Northeastern Thailand

Abstract. Yatar C, Thinkampheang S, Sungkaew S, Wachrinrat C, Asanok L, Kamyo T, Hermhuk S, Kachina P, Thongsawi J, Phumphuang W, Yarnvudhi A, Waengsothorn S, Cheysawat S, Marod D. 2024. The dynamics of deciduous dipterocarp forest in relation to climate variability in the Sakaerat Biosphere Reserve, Northeastern Thailand. Biodiversitas 25: 3088-3098. Climate change is a major environmental problem influencing forest dynamics. To clarify tropical seasonal forest dynamics under climate change, we conducted long-term monitoring of all trees with Diameter at Breast Height (DBH) ?4.5 cm within a 1-ha permanent plot established in 2004 in a deciduous dipterocarp forest in the Sakaerat Biosphere Reserve (SBR), Northeastern Thailand. Surveys of all trees within the plot with DBH ?2 cm were conducted in 2008, 2015, and 2019. Climate data were obtained from the SBR climate station during 2004-2019 and used to extract dates with drought and wet conditions. Forest dynamics varied among species and periods, with stem density exhibiting a decreasing trend. Despite prolonged drought conditions from 2004 to 2009, which usually leads to increased mortality rates, the recruitment rate was 7-fold higher than the mortality rate at a site protected from fire during 2004-2008, and most of the recruited species were pioneer species, shrubs, and small trees. A contrasting trend was observed during 2015-2019, with a mortality rate almost 10-fold higher than the recruitment rate, indicating a significant ecological disturbance, likely to have been driven by a severe El Niño event during 2015-2016. Thus, climate induced disturbances (i.e., drought and fire) appear to have inhibited tree regeneration in the deciduous dipterocarp forest, particularly when they occurred in combination and for specific timing and intensity levels. Addressing the challenges posed by drought and fire to tree regeneration requires holistic management approaches that consider both ecological and climatic factors. Monitoring and adaptive management are also essential to mitigate the impact of future disturbances and support the long-term viability of forest ecosystems.

Architectural approach to evaluate the design and management of almond cultivars suitable for super high-density orchards.

The almond tree is a major global nut crop, and its production has surged dramatically in recent years. Super high-density (SHD) planting systems, designed to optimize resource efficiency and enhance precocity, have gained prominence in almond cultivation. A shift in cropping systems toward sustainable intensification (SI) pathways is imperative, and so maximizing branching density within the canopies of SHD trees is crucial to establish and maintain productive potential, especially for hedge-pruned trees. This study investigates the influence of different almond cultivars grafted onto a novel growth-controlling rootstock on tree architectural and growth parameters in a SHD orchard. This open field research provided valuable insights for the development and application of new tools and methods to increase productivity and sustainability in almond growing. Three cultivars (Lauranne® Avijour, Guara Tuono, and Filippo Cea) were evaluated in Gravina in Puglia (BA) over a two-year period. Canopy growth parameters, such as canopy volume and trunk cross-sectional area, and architectural traits, like branching density, branching angle, number and length of subterminal shoots, and number of brachyblasts, were measured through qualitative and quantitative measurements. Results revealed significant differences in tree height, canopy thickness, width, volume, and vigor among the cultivars. Architectural traits, including branch parameters, brachyblast parameters, and subterminal shoots, varied among the cultivars. Lauranne displayed a more compact well-distributed canopy and exhibited the lowest vigor. Filippo Cea showed the highest vigor and the greatest canopy volume. Tuono had a higher number of buds and bud density. The best ideotype for SHD orchards is a smaller tree, with high branching density and smaller trunk diameters, i.e. the vigor. Cv. Lauranne seemed to be the best cultivar, mostly with the lowest tree vigor of all the cultivars involved. These findings provide valuable insights for almond growers and breeders seeking to optimize orchard design and management for enhanced SHD orchards productivity and sustainability. Future research will explore the relationship between canopy architecture and yield parameters, considering different scion/rootstock combinations in different environmental conditions.

A new cloud forest tree Lychnodiscus bali (Sapindaceae), Critically Endangered from the Bali-Ngemba Forest Reserve, NW Region, Cameroon

SummaryWe describe and illustrate Lychnodiscus bali Cheek (Sapindaceae), a new species to science, from the Bali Ngemba Forest Reserve of NW Region Cameroon, the last major remnant of cloud forest in the Bamenda Highlands of Cameroon, recently evidenced as a Tropical Important Plant Area (TIPA or IPA). Confined on current evidence to upper submontane forest, the new species is threatened by expanding habitat clearance for farms and is assessed as Critically Endangered. A small tree, attaining 3 – 4 m height, it is the first new species to be added to this Guineo-Congolian tree genus in 50 years, the third recorded from Cameroon and takes the number of species in the genus to eight. It has the highest known altitudinal range (1700 – 1950 m alt.) of any species of the genus. We discuss its discovery in the context of other recently discovered and highly threatened or even extinct plant species in the Cameroon Highlands, and the importance of their conservation. The new species was previously identified as Lychnodiscus grandifolius Radlk., but differs in the shorter length of the distal leaflets (12 – 18 cm vs 22 – 39 cm long); in the abaxial leaf surface lacking glands (vs glands flat and conspicuous); in being sparsely hairy all over (vs glabrous except the main veins) and in its larger flowers, 8 – 11 mm long at anthesis (vs 5 – 7 mm long). We present an identification key of the species of Lychnodiscus and discuss their classification in the context of recent molecular phylogenetic and phylogenomic studies. The authors contend that Lychnodiscus Radlk., previously placed in Cupanieae by Radlkofer, should now be placed in the reconstituted Nephelieae in the revised 2021 intrafamilial classification of Buerki et al., probably close to the genera Aporrhiza Radlk. and Laccodiscus Radlk. However, until the genus is included in molecular studies this cannot be confirmed and a sister relationship remains speculative.

Range-Wide Assessment of Recent Longleaf Pine (Pinus palustris Mill.) Area and Regeneration Trends

Longleaf pine (Pinus palustris Mill.) is a conifer historically associated with an open forest ecosystem that extended across much of the coastal plain of the Southeastern United States. It now exists mainly in isolated fragments following the conversion of forests and the long-term disruption of the low-intensity fire regime upon which the species depends. Recent decades have seen efforts to restore longleaf pine forests by government and private landowners. This was reflected in analyses of national forest inventory data during two time periods, ca. 2009–2015 and 2016–2021, that showed increases in the estimated number of longleaf pine trees, the area of the longleaf pine forest type, and the number and area of planted longleaf pine, along with growth in mean plot-level longleaf pine carbon and importance value. At the same time, we found a decrease in the overall forest area containing longleaf pine, manifested across a variety of other forest types. These results point to a dynamic through which forests dominated by longleaf pine are becoming more widespread via restoration, while forests in which the species is a less important component are transitioning to other forest types or land uses. We also detected a decrease over time in the estimated number of longleaf seedlings across most states and forest types and a decline in naturally regenerated longleaf pine. To further assess regeneration trends in longleaf pine, we calculated the estimated proportion of small trees (seedlings and saplings) for the entire species and for seed zone sub-populations. We found a species-wide decrease in the proportion of small trees, from 82.1 percent to 75.1 percent. This reduction was most pronounced along the edges of the species distribution and could indicate less sustainable levels of regeneration in some areas. These results underscore the challenges of facilitating natural regeneration in this important species.

Spatial decoupling of taxon richness, phylogenetic diversity and threat status in the megagenus Erica (Ericaceae).

Estimates of the number of vascular plant species currently under threat of extinction are shockingly high, with the highest extinction rates reported for narrow-range, woody plants, especially in biodiversity hotspots with Mediterranean and tropical climates. The large genus Erica is a prime example, as a large proportion of its 851 species, all shrubs or small trees, are endemic to the Cape Floristic Region (CFR) of South Africa. Almost two hundred are known to be threatened and a further hundred are 'Data Deficient'. We need to target conservation efforts and research to fill the most problematic knowledge gaps. This can be especially challenging in large genera, such as Erica, with numerous threatened species that are closely related. One approach involves combining knowledge of phylogenetic diversity with that of IUCN threat status to identify the most Evolutionarily Distinct and Globally Endangered (EDGE) species. We present an expanded and improved phylogenetic hypothesis for Erica (representing 65% of described species diversity) and combine this with available threat and distribution data to identify species and geographic areas that could be targeted for conservation effort to maximise preservation of phylogenetic diversity (PD). The resulting 39 EDGE taxa include 35 from the CFR. A further 32 high PD, data deficient taxa are mostly from outside the CFR, reflecting the low proportion of assessed taxa outside South Africa. The most taxon-rich areas are found in the south-western CFR. They are not the most phylogenetically diverse, but do include the most threatened PD. These results can be cross-referenced to existing living and seed-banked ex situ collections and used to target new and updated threat assessments and conservation action.

Bocconia frutescens little leaf, a new plant disease associated to a ´Candidatus Phytoplasma pruni´ related strain in Costa Rica

Objective/Background. Bocconia frutescens (Papaveraceae) is a small tree distributed naturally from Mexico to Argentina and the Caribbean Bassin. Bocconia trees showing symptoms resembling phytoplasmas infection, such as little leaves and witches´-broom, were found in Cartago province, Costa Rica. Detection and identification of the potential phytoplasmas associated with B. frutescens little leaf symptoms was the objective out of this study. Materials and Methods. Evaluation of leaves tissue using transmission electron microscopy (TEM), nested PCR using universal and specific primers to amplify phytoplasmas 16S rRNA and secA genes. Nucleotidic sequences (Sanger method) were obtained from amplicons, and used for BLASTn, phylogenetic analyses, and in silico RFLP’s. Results. Presence of phytoplasmas into phloem tissue, only in symptomatic trees, was evidenced by TEM. Comparison of partial sequences (16Sr and secA genes) by BLASTn, in silico RFLP´s and phylogenetic analyses, showed the occurrence of a ´Candidatus Phytoplasma pruni´ related strain in the samples evaluated. Conclusion. Phytoplasmas were found only in the symptomatic B. frutescens trees evaluated. The phytoplasmas were identified as a ´Ca. Phytoplasma pruni´ related strain. This is the first report of B. frutescens as a natural host of ´Ca. Phytoplasma pruni´.

Clerodendrum trichotomum Thunberg-An Ornamental Shrub with Medical Properties.

Harlequin glory bower (Clerodendrum trichotomum) is a shrub or small tree belonging to the Lamiaceae family, native to Japan, Korea, and eastern China. It has esthetic value and in Europe, it is cultivated as an ornamental plant. Its sweet-smelling flowers have a white or pink crown. The calyx turns from green to pink-purple over time, providing an especially decorative touch around surrounding the ripe deep-blue fruits that persist until winter. In the areas of its natural occurrence, the leaves and young shoots of C. trichotomum, and sometimes the roots, flowers and fruits, are used in folk medicine due to its anti-inflammatory, analgesic, anticancer, sedative, and hypotensive effects. Products based on Harlequin glory are also used in the treatment of rheumatoid arthritis, joint pain, skin inflammation, or asthma. Preliminary research on the composition of raw material suggests that its health-promoting effect is associated with the presence of numerous secondary metabolites, including phenylpropanoids, flavonoids, lignans, terpenoids, steroids, alkaloids, and anthraquinones. This work reviews the current state of knowledge about the phytochemistry and in vitro and in vivo pharmacological properties of the extracts and main active components isolated from C. trichotomum. It also indicates that before it can be used in modern medicine, further research is necessary regarding the safety and efficacy of the raw material, its mechanisms of action, and dosage.

Redefining the megagenus Erica L. (Ericaceae): the contributions of E. G. H. Oliver and I. M. Oliver (née Nitzsche) to taxonomy and nomenclature.

The megagenus Erica L. (Ericaceae), as it is recognised today, includes 851 species of evergreen shrubs or small trees, the majority of which are endemic to the Cape Floristic Region of South Africa. From the first descriptions in Linnaeus's Genera plantarum, a succession of authors ascribed the steadily accumulating numbers of known species to various of a total of 72 different genera. Until the latter half of the twentieth century, so called 'minor genera' such as Philippia Klotzsch and Blaeria L. were still recognised for many African species. The now uncontroversial inclusive circumscription of Erica, and a substantial proportion of its currently recognised species diversity, was conceptualised, described, and illustrated by the South African botanists E. G. H. ('Ted') Oliver and Inge M. Oliver in a succession of works published from 1964 to the present day. We review the historical development of generic delimitation in Erica sens. lat., focusing on the contribution of the Olivers to the current state of systematic knowledge of the genus, and presenting an overview and complete lists of literature and of taxa that they authored.

Influence of tree size on the scaling relationships of lamina and petiole traits: A case study using Camptotheca acuminata Decne.

There is a lack of research on whether tree size affects lamina and petiole biomass allocation patterns, whereas the trade-off between leaf biomass allocated to the lamina and the petiole is of significance when considering the hydraulic and mechanical function of the leaf as a whole. Here, Camptotheca acuminata Decne was selected for study because of the availability of trees differing in size growing under the same conditions. A total of 600 leaves for two tree size groups and 300 leaves per group differing in height and trunk diameter were collected. The lamina fresh mass (LFM), lamina dry mass (LDM), lamina area (LA), petiole fresh mass (PFM), and petiole length (PL) of each leaf was measured, and reduced major axis regression protocols were used to determine the scaling relationships among the five functional traits. The bootstrap percentile method was used to determine if the scaling exponents of the traits differed significantly between the two tree size groups. The results indicated that (i) there was a significant difference in the LFM, LDM, PFM, PL, LMA, LFMA and PFM/LFM between large and small trees, but no significant difference in LA; (ii) the LA versus LFM, LA versus LDM, LFM versus PFM, LA versus PFM, and PL versus PFM scaling relationships of the two groups were allometric (i.e., not isometric); (iii) there were significant differences in the scaling exponents of LA versus LFM, LA versus PFM, PL versus PFM between the two groups, but there was no significant difference in the LFM versus PFM scaling relationship between the two groups of trees. The data were also consistent with the phenomenon known as "diminishing returns". These data indicate that tree size influences leaf biomass allocation patterns in ways that can potentially influence overall plant growth, and therefore have an important bearing on life-history strategies.

Stand biomass of Pinus sylvestris var. mongolica plantations benefits from high density monocultures in the boreal zone

Pinus sylvestris var. mongolica (P. sylvestris) plantations are extensively established in the boreal zone. Increasing stand biomass of these plantations can effectively enhance carbon stock, which is crucial for mitigating climate change. However, the current understanding of optimizing plantation strategies to maximize stand biomass is primarily derived from experiments in tropical and subtropical zones, which is difficult to extend to the boreal due to substantial climatic differences. Based on a comprehensive dataset from 1,076 sample plots of P. sylvestris plantations in the boreal zone of China, we evaluated the effects of tree species richness and stand density on tree height, diameter at breast height (DBH), and stand biomass to investigate the optimal plantation strategy. Furthermore, we examined how these effects changed with stand age and investigated their relative importance. We found that monocultures at a high stand density of 2,000–2,500 ​ha−1 were the optimal plantation strategy to maximize stand biomass (107.5 ​Mg·ha−1), and this held true at almost all stand ages. Unfortunately, this strategy resulted in low species richness and small individual trees (10.6 ​m height and 9.8 ​cm DBH), thus presenting a trade-off. In addition, as stand age increased, the effect of tree species richness on stand biomass shifted from positive to negative, but the effect of stand density was always positive. Overall, stand age had the greatest effect on stand biomass, followed by stand density and then tree species richness. Our findings reveal a distinct plantation strategy for optimizing stand biomass of P. sylvestris plantations in the boreal zone. More importantly, this study highlights that (1) maximizing stand biomass in the boreal zone may compromise tree species richness; (2) net effects of tree species richness on stand biomass are not always positive, as negative selection effects offset positive complementary effects.