Plant Systems Research Articles

Analysis of Battery Technologies for Use as Battery Management Systems in a Simple Solar Power Plant

A solar power plant is a device that uses solar radiation to generate electricity. However, a dependable energy storage system is essential to effectively operating solar power plants. This study aims to examine how battery technology is used in solar power plants as a voltage storage. Specifically, the performance of lithium-ion and lead acid batteries, known as valve-regulated lead acid (VRLA), will then be compared. The findings demonstrate that Lithium-ion Batteries are better at keeping a steady voltage in no-load situations. The highest voltage value was recorded at 13:79 V at a 90° tilt angle and 13:00 Indonesia time. At the same hour, the VRLA Battery recorded the lowest voltage of 12.08 V with a 0° tilt angle. Under load conditions, the Lithium-ion Battery performed better with a more moderate voltage drop, achieving the lowest voltage of 12.68 V at an inclination angle of 165° and 14:00 Indonesia time, compared to the VRLA Battery's lowest value of 12.08 V under comparable conditions. Thus, Lithium-ion Batteries are thought to be more efficient and stable than VRLA Batteries in solar power plant applications, particularly in terms of voltage stability under changing operating conditions. Furthermore, battery selection should still take into account the initial investment cost and the unique requirements of the solar power plant system to be deployed.

Effectiveness of a dynamic living wall system of plants on indoor thermal environment in summer - an experimental study

Optimizing vertical greening systems to reduce their negative impact on buildings is important to reduce energy consumption. To reduce the long-term effects of fixed living plant walls on building facades, this study proposes an optimization scheme for dynamic living plant walls (DLWS). By combining dynamic building facades with living plant walls, this study analyzes the effectiveness of DLWS, fixed living plant walls (LWS), and dynamic shading sails (DSS) in regulating indoor temperature and humidity through controlled experiments. The results showed that DLWS and LWS had the same effect on cooling, reducing the average indoor temperature by 3.6°C during the daytime. Further, DLWS was able to increase the indoor air humidity within the appropriate range, which was lower than the LWS humidity by 6.9 RH. DLWS had a better cooling effect compared to DSS, and DLWS can reduce the indoor temperature by 2.7. The results authenticate the performance advantages and the possibility of applying dynamic plant living walls in practice.

Generation of root zone soil moisture from the integration of an all-weather satellite surface soil moisture estimates and an analytical model: A preliminary result in China

In addition to surface soil moisture (SSM) data, root zone soil moisture (RZSM) is particularly significant for irrigation decision-making and agricultural drought warnings since water uptake generally occurs through the root systems of plants. In this study, a daily/0.05° RZSM dataset covering the major land areas of China was generated from the synergistic use of satellite-derived SSM estimates and a RZSM-SSM analytical model. First, based on the SSM and RZSM datasets generated from the fifth generation of atmospheric reanalysis (ERA5-Land), the Markov Chain Monte Carlo algorithm was applied to optimize the soil moisture analytical relationship (SMAR) model to determine four essential parameters pixel-to-pixel over the study area. In addition, the optimized SMAR parameters were integrated with satellite-derived daily/0.05° SSM to predict the daily/0.05° RZSM in China. Finally, due to the lack of in situ RZSM measurements ground truth at a spatial resolution of 0.05°, two RZSM products, namely the Soil Moisture Active Passive (SMAP)-based RZSM and the China Meteorological Administration Land Data Assimilation System (CLDAS)-based RZSM, were used as references to preliminarily assess the estimated data. The results showed overall fair correlations between SMAP_RZSM and estimated RZSM (correlation coefficient R varying from 0.557 to 0.655), and between CLDAS_RZSM and estimated RZSM (correlation coefficient R varying from 0.496 to 0.596) over four typical days representing spring, summer, autumn, and winter in 2019. Although the proposed approach may overestimate or underestimate RZSM compared to the two referenced products in different seasons, an overall acceptable accuracy with unbiased root mean square error of ∼ 0.070–0.090 cm3/cm3 was obtained.

Equipment control algorithm for cooling plant based on graph theory and path planning

This paper presents a novel path planning-based start-stop control algorithm for equipment in cooling plants designed to address the limitations of traditional serial start-stop control logic. The algorithm employs graph theory and path planning techniques to abstract the cooling plant schematic into a directed graph, enabling the selection of appropriate control paths and facilitating effective start-stop control decisions for the equipment. A key feature is the dynamic updating of the graph after each operation, which enables adaptive control target adjustments and prevents control blocking issues. Validation with real case scenarios demonstrates the effectiveness of the algorithm in automatic start-stop control, identifying equipment deviations, and handling faulty equipment switching. The algorithm also has the ability to handle some incorrectly turned on equipment, shutting down redundant equipment in the cooling plant system that is not in efficient operation. This algorithm shows the potential as an underlying execution algorithm of an advanced optimization algorithm to accelerate the implementation of advanced optimization algorithms.

Environment-friendly Synthesis of AgNPs from Fimbristylis miliacea Flower Extract: Characterization and its Applications as an Antioxidant Activity, Anticancerous Activity and in the Reduction of 4-Nitrophenol

Background: Silver metal is useful in a variety of fields. Different silver salts exhibit good application in the organic transformation. The use of a green methodology in AgNPs preparation has gained interest of young researchers. Plant systems are employed in the green approach of preparing AgNPs, serving as both a stabilizing and reducing agent. Silver nanoparticles (AgNPs) made from silver salts exhibit a variety of biological activities and may be useful in organic transformation. Method: AgNPs were synthesized with the use of flower extract from Fimbristylis miliacea, which acts as a stabilizing and reducing agent. Result: Fimbristylis miliacea flower extract is used as a reducing and stabilising agent for preparation of AgNPs. These synthesised AgNPs were characterised by using FTIR, XRD, FESEM/ EDS, HR-TEM, TGA, and ICP-AES. Fimbristylis milliciea flower extract was subjected to FTIR and HR-LCMS analysis in order to identify the phytoconstituents that are responsible for the reduction of AgNO3. The HR-TEM shows particle size between 8.98434+0.69669nm and 19.07464+1.4384nm. The size of AgNPs determined by using HR-TEM shows good agreement with XRD particle size. The synthesized AgNPs show excellent antioxidant properties with IC50=56.45 μg/mL. The present study confers significant cytotoxic activity against MDA-MB-231 human breast cancer cell line culture (IC50= 61.97 μg/ml). The AgNPs show a faster reduction of 4-nitrophenol. Conclusion: In conclusion, we have prepared AgNPs by using Fimbristylis miliacea flower extract. The study further concludes that green synthesis of AgNPs has many advantages as compared to chemical methods, such as cost-effectiveness, rapid, and environment-friendly methods. The results indicated that the biosynthesized AgNPs have significant cytotoxic activity against the MDA-MB-231 breast cancer cell line. Further, it indicates that biosynthesized AgNPs can be a potential alternative agent for human breast cancer therapy. The cytotoxic potential can be used for treatments and provides a new method to develop molecules for cancer therapy. The catalytic activity of AgNPs was examined by using the reduction of 4-nitrophenol. It shows that the reduction of 4-nitrophenol in 6 minutes is confirmed by using 1H NMR analysis.

Human parvovirus B19 virus-like particle formation in Nicotiana benthamiana

There has been a surge in the interest to utilize plants as hosts for producing vaccine antigens. In this study, we demonstrated the successful expression of the human parvovirus B19 (B19V) capsid protein (VP2) in Nicotiana benthamiana cells. The B19V VP1 and VP2 genes were cloned under the control of estrogen-inducible promoters and transiently expressed in N. benthamiana leaves using the agroinfiltration method. The addition of estrogen significantly boosted the expression of VP2. Furthermore, codon optimization of the VP2 sequence resulted in over a 30-fold increase in its expression compared with that of the wild-type. Analysis of negatively stained samples by sucrose density gradient ultracentrifugation and electron microscopy revealed that the expressed VP2 proteins formed spherical particles with diameters of approximately 20 nm. Immunostaining analysis of protoplasts derived from VP2-expressing N. benthamiana leaves indicated that VP2 signals were predominantly localized in the cytoplasm. These findings strongly suggested that B19V VP2 assembles and formed virus-like particles (VLPs) within the cytoplasm of N. benthamiana cells, presenting a promising method for producing B19V VLPs in plant systems.

Discrete element modelling and mechanical properties and cutting experiments of Caragana korshinskii Kom. stems.

The forage crop Caragana korshinskii Kom. is of high quality, and the biomechanical properties of its plant system are of great significance for the development of harvesting equipment and the comprehensive utilisation of crop resources. However, the extant research on the biomechanical properties of Caragana korshinskii Kom. is inadequate to enhance and refine the theoretical techniques for mechanised harvesting. In this study, we established a discrete element model of CKS based on the Hertz-Mindlin bonding contact model. By combining physical experiments and numerical simulations, we calibrated and validated the intrinsic and contact parameters. The Plackett-Burman design test was employed to identify the significant factors influencing bending force, and the optimal parameter combination for these factors was determined through response surface analysis. When the shear stiffness per unit area was 3.56×109 Pa, the bonded disk scale was 0.93 mm, the normal stiffness per unit area was 9.68×109 Pa, the normal strength was 5.62×107 Pa, the shear strength was 4.27×107 Pa, the discrete element numerical simulation results for three-point bending, radial compression, axial tension, and shear fracture exhibited a maximum failure force error of 3.32%, 4.37%, 4.87% and 3.74% in comparison to the physical experiments. In the cutting experiments, a smaller radial angle between the tool edge and the stem resulted in less damage to the cutting section, which was beneficial for the smoothness of the stubble after harvesting and the subsequent growth of the stem. The discrepancy in cutting force between the physical and numerical simulations was 3.89%, and the F-x (force versus displacement) trend was consistent. The multi-angle experimental validation demonstrated that the discrete element model of CKS is an accurate representation of the real biomechanical properties of CKS. The findings offer valuable insights into the mechanisms underlying crop-machine interactions.

Development of a diagnostic system for a hybrid power plant of a light aircraft

Development of a diagnostic system for a hybrid power plant of a light aircraft

Разработка методики расчета составляющих резерва тепловой экономичности парогазовых установок

The components of the thermal efficiency reserve of thermal power plant equipment are the overexpenditure or savings of fuel due to the deviation of the actual values of the equipment performance from their nominal values. They are determined in tons of reference fuel for a certain period. The components of the thermal efficiency reserve are the most essential element of the technical record-keeping and reporting systems of power plants. They allow us to quantitatively assess the technical condition of the equipment and, on this basis, effectively plan repair programs. The methods to calculate the components of the thermal efficiency reserve of steam power plants are well developed and regulated according to the regulatory documents. Regulatory requirements for combined-cycle plants in this area contain inaccuracies and do not cover a full list of the components of the thermal efficiency reserve. Thus, it is necessary to develop a method that allows us to calculate the components of the thermal efficiency reserve of combined-cycle plants. When developing the methodology for combined-cycle plants, the authors have applied the approaches to calculate the components of the thermal efficiency reserve that are used for steam power plants. In addition, available methods for assessing the thermal efficiency of thermal power plant equipment have been used. The developed methods have been tested based on actual data on the operation of combined-cycle plant PGU-116. A methodology to calculate the components of the thermal efficiency reserve of combined-cycle plants with waste-heat boilers without fuel afterburning has been developed. The methodology has been tested in assessing the thermal efficiency indicators of combined-cycle plant in operation. Shortcomings in regulatory documents of the energy industry in terms of calculating the components of the thermal efficiency reserve of combined-cycle equipment have been identified. The developed methodology can be recommended for use in the systems of technical record-keeping and reporting of power plants when monitoring the indicators of thermal efficiency of combined-cycle plants. To ensure the objectivity of the results of the analysis of the efficiency of operated combined-cycle power units in Russia, it is necessary to adjust industry regulatory documents. They should contain uniform scientifically substantiated methods for calculating the components of the reserve of thermal efficiency of combined-cycle equipment.

Rancang Bangun Grounding Box Soil Treatment Sebagai Media Pengukuran Resistansi Pentanahan untuk Proteksi Pembangkit Hybrid PV – Angin Politeknik Negeri Malang

This study addresses the issue of high resistance in the grounding system of the Savonius-Solar Hybrid Power Plant at Politeknik Negeri Malang, caused by rocky and sandy soil conditions, with an initial resistance value of 35 Ω. The purpose of this research was to test the effectiveness of soil treatment using bentonite, charcoal, and salt in reducing resistance to meet the PUIL 2011 standard (<5 Ω). This study employed an experimental method with a quantitative approach, measuring resistance values before and after soil treatment application using a three-point earth tester.The results showed that soil treatment successfully reduced the soil resistance from 35 Ω to 2.85 Ω, meeting the maximum standard. This finding indicates that soil treatment is effective in improving the safety and reliability of grounding systems, making it beneficial for application in similar electrical systems located in areas with challenging soil characteristics.

Optimization of Steam Boiler Airflow Control System in a Typical Oil Refinery Power Plant

This paper presents optimization of Steam Boiler Airflow Control System in a Typical Oil Refinery Power Plant. The power plant is equipped with four steam boilers using a damper-louvers airflow control system. Analysis has revealed significant energy wastage due to inefficiency and over-air supply, with the system requiring 59,904,436 kWh annually at a financial cost of N1, 093,255,884. The existing system's inefficiency results in an annual electrical energy waste of 8,502,302 kWh. This inefficiency is attributed to the Force Draft Fan (FDF) motor operating at maximum speed continuously, regardless of the steam profile or airflow requirements. This study aimed at optimizing the steam boiler airflow control system in a typical oil refinery power plant for improved power efficiency, energy conservation, and cost savings citing Port Harcourt Refinery Company (PHRC) at Alesa-Eleme, Rivers State, Nigeria. To address this, the damper-louvers system was replaced with a Variable Frequency Drive (VFD), which would adjust the motor speed to match the required airflow, thereby reducing energy wastage. The process was simulated and VFD/FDF motor analyzed in MATLAB Simulink, determining the optimal speed, airflow, and power requirements. Results obtained show that the VFD control system improves the FDF motor's power efficiency from 47.7% to 85%, with an annual energy saving of 8,502,302 kWh (8.5 GWh). This results in a total cost benefit of N478.18 million annually, representing a 43.8% cost saving. The implementation cost of the VFD infrastructure was estimated at N111, 440,000, with a payback period of approximately eleven months. The findings suggest deployment of higher FDF motor speed ratings to enhance speed control and energy efficiency in Oil refinery power plant.

Ornamental Plant Growth in Different Culture Conditions and Fluoride and Chloride Removals with Constructed Wetlands

Natural water resources often contain fluorides and chlorides due to wastewater discharge; however, excessive exposure to fluorides can pose health risks to humans. Elevated chloride levels can negatively affect aquatic fauna and disrupt the reproductive rates of plants. This study assessed constructed wetlands (CWs) featuring monocultures (including Canna hybrid, Alpinia purpurata, and Hedychium coronarium) and polycultures (combinations of species from the monoculture systems) of ornamental plants (OPs) to evaluate their efficiency in removing fluorides and chlorides. The results revealed that the ornamental plants flourished in the CW conditions without sustaining any physical damage. C. hybrid demonstrated the longest roots and the highest volume, as well as greater height compared to other species. However, this did not affect the ion removal efficiency. In polyculture systems, 42.2 ± 8.8% of fluoride was removed, a result that was not significantly different (p > 0.05) from the removal rates observed in monocultures of C. hybrid (42.5 ± 7.5%), H. coronarium (36.8 ± 7.0%), or A. purpurata (30.7 ± 7.9%). For chloride, a similar pattern emerged, with 32.4 ± 4.8% removed in constructed wetlands (CWs) using a polyculture of ornamental plants, a figure that was also not significantly different (p > 0.05) from the removal percentages in monocultures of C. hybrid (29.1 ± 5.3%), H. coronarium (28.1 ± 5.0%), or A. purpurata (32.0 ± 5.7%). Our results indicate that CWs with polyculture species contribute to pollutant removal at levels comparable to those found in monoculture systems. However, polyculture systems offer enhanced aesthetic appeal and biodiversity, incorporating various ornamental flowering plants. The use of this eco-technology for removing fluoride and chloride pollutants helps prevent river contamination and associated health issues.

Determining the reliability function of the thermal power system in power plant 'Nikola Tesla, Block B1' using the Weibull distribution

The assessment of thermal power system reliability represents a key step towards maintaining the stability and efficiency of the system. Through the application of mathematical models, risk analysis, and maintenance strategies, it is possible to optimise system performance and reduce the risk of failures. This paper presents an assessment of the reliability of the thermal energy system in fossil fuel power plant ‘Nikola Tesla, Block B1’, based on a twelve-year failure database. By implementing the theory of reliability, based on statistics and theory of possibility, and using the simple and complex two-parameter Weibull distribution, the theoretical functions of the failure rate are determined. A significant advantage of such a study is the opportunity of an early and in-depth understanding of the logic and mechanisms of system risk behaviour, and a more precise assessment of its functioning throughout future exploitation.

Improving Nutrient Uptake Efficiency in Hydroponic Systems With Phytoremediation of Nitrate‐Nitrogen Contaminated Wastewater

ABSTRACTThis study evaluates the efficacy of a nutrient film technique (NFT) hydroponic system in phytoremediation of nitrate‐nitrogen contaminated wastewater using six plant species: vetiver grass (Chrysopogon zizanioides), golden pothos (Epiprennum aureum), crotons (Codiaeum variegatum), arrowhead plant (Syngonium podophyllum), spinach (Spinacia oleracea), and brinjal (Solanum melongena). This study examines how well different plant species remove nitrate‐nitrogen from wastewater in an NFT hydroponic system. It finds that all plants, but especially money plant and arrowhead plant, successfully lower nitrate levels at influent concentrations of 30 and 90 mg/L. The wastewater had average pH values of 5–6.5, temperature values of 24°C–25°C, electrical conductivity values (EC) of 1.5–2 mS/cm, and total dissolved solids (TDS) between 1062 ± 199.3 and 1400 ± 124.16 mg/L. The system for golden pothos (70.94%–90.3%), crotons (62.5%–83.1%), arrowhead plant (67.25%–90.03%), vetiver grass (45.42%–83.1%), spinach (47.15%–81.71%), and brinjal (59.52%–83.38%) has shown excellent biochemical oxygen demand (BOD5) elimination efficiency. These results suggest that nitrate‐nitrogen contaminated wastewater can be effectively cleaned up by NFT hydroponic systems, which employ certain plant species.

Research Progress of Single-Cell Transcriptome Sequencing Technology in Plants

Multicellular organisms exhibit inherent cellular heterogeneity that cannot be captured by traditional high-throughput sequencing techniques, resulting in the unique cellular characteristics of individual cells being neglected. Single-cell transcriptome sequencing (scRNA-seq) technology can be used to determine the gene expression levels of each individual cell, facilitating the study of intercellular expression heterogeneity. This review provides a comprehensive overview of the development and applications of scRNA-seq technology in plant research. We highlight the significance of integrating single-cell multi-omics approaches to achieve a holistic understanding of plant systems. Additionally, we discuss the current challenges and future research directions for scRNA-seq technology in plant studies, aiming to offer valuable insights for its application across various plant species.

High-Level Production of a Recombinant Protein in Nicotiana benthamiana Leaves Through Transient Expression Using a Double Terminator.

Various bio-based recombinant proteins have been produced for industrial, medical, and research purposes. Plants are potential platforms for recombinant protein production because of several advantages. Therefore, establishing a system with high target gene expression to compensate for the low protein yield of plant systems is crucial. In particular, selecting and combining strong terminators is essential because the expression of target genes can be substantially enhanced. Here, we aimed to quantify the enhancement in the fluorescence intensity of the turbo green fluorescence protein (tGFP) caused by the best double-terminator combinations compared to that of the control vector using agroinfiltration in Nicotiana benthamiana leaves. tGFP fluorescence increased by 4.1-fold in leaf samples infiltrated with a vector containing a double terminator and markedly increased by a maximum of 23.7-fold when co-infiltrated with the geminiviral vector and P19 compared to that in constructs containing an octopine synthase terminator. Polyadenylation site analysis in leaf tissues expressing single or dual terminators showed that the first terminator influenced the polyadenylation site determination of the second terminator, resulting in different polyadenylation sites compared with when the terminator is located first. The combination of the high-expression terminators and geminiviral vectors can increase the production of target proteins.

The Impact of Nanobubble Gases in Enhancing Soil Moisture, Nutrient Uptake Efficiency and Plant Growth: A Review

Nanobubble (NB) technology in agriculture has received increased interest due to its potential to promote soil moisture retention and plant development. Therefore, this review investigates the impact of various types of NBs—such as oxygen, carbon dioxide, and air—on soil and plant systems. Various studies revealed that nanobubble-saturated water (NBSW) increases moisture retention, microbial activity, and nutrient absorption, which contribute to better plant development. However, there are still gaps in understanding the specific roles of different gases regarding their stability, interactions with soil, and long-term agricultural impacts. This review aims to combine previous research by focusing on various types of NBs impact on soil moisture, water quality, and nutrient retention. Challenges include the quick dissolution of particular gases, limited field studies, and scalability. The analysis showed that despite these challenges, NBs have potential for enhancing agriculture by improving soil structure and crop yield. More study is needed to maximize their application, particularly in determining the most effective gas types and concentrations for certain agricultural areas.

Assessment of Yield and Economics under High Density Planting System in Cotton in Kachchh District of Gujarat, India

Cotton (Gossypium hirsutum L.) possesses a position of major fiber and cash crop, which plays vital role to sustain national economy. It provides the basic raw material (cotton fiber) to cotton textile industry. Gujarat contributes substantially to the national cotton area (24%) and productions (37%). A field experiment was carried out during the kharif seasons from 2017-18 to 2019-20 at farmers' fields through ICAR-CAZRI Krishi Vigyan Kendra Kachchh-II to evaluate the impact of frontline demonstrations (FLDs) on cotton productivity and profitability. During the experiment period, a total of 30 FLDs on high density planting system (HDPS) in cotton with the high-yielding variety GTHH-49 were demonstrated in a 12-hectare area across 6 villages in the Bhuj, and Nakhatrana talukas of Kachchh district. The improved variety GTHH-49 with a full package of practices was demonstrated in the plots, while existing technology was treated as the local check. Based on three years of data, the improved practice (IP) resulted in an average seed yield of 2868 kg ha-1, which was an increase of 13.35% compared to the local check yield of 2530 kg ha-1. The demonstrated technology showed an average extension gap, technology gap, and technology index of 338.33 kg ha-1, 631.67 kg ha-1, and 18.05%, respectively. The economic analysis of the demonstrations revealed the viability of the improved technology, with a net return of 101670.3 Rs. ha-1 and a benefit-cost ratio (BCR) of 3.24, compared to 84964.67 Rs. ha-1 and a BCR of 3.02 for local check. A wide range of extension and technology gaps had a detrimental influence on crop output and net returns in general. The results revealed that the adoption of the high-yielding variety with a full package of practices significantly increased cotton productivity and reduced both extension and technology gaps.

The combined analysis of transcriptome and phytohormone provides new insights into signaling mechanism for lateral root formation of tea plant (Camellia sinensis)

The growth and development of lateral roots (LRs) determine the nutrient absorption and environmental adaptability of tea plant, playing a crucial role in the economic efficiency of tea plantations. However, the molecular mechanisms underlying the formation of LRs in tea plant remain unreported. In this study, we established a LRs induction system in tea plants by exogenously adding N-1-naphthylphthalamic acid (NPA) and naphthaleneacetic acid (NAA). The molecular mechanisms of LRs formation were analyzed through transcriptomics and endogenous hormone measurements. Results showed that NAA treatment could counteract the inhibitory effect of NPA on LRs formation and promote the generation of LRs in tea plant. The addition of exogenous NAA reduced the levels of auxin and zeatin in the root tips while increasing the content of abscisic acid (ABA). Transcriptomic analysis at four time points (2, 6, 12, and 24 h) after NAA vs. MOCK treatment revealed 78 different expression genes (DEGs) associated with plant hormone signaling pathways. Among these, the auxin signaling pathway was the most significant in responding to the LRs formation in tea plant. Weighted Gene Co-Expression Network Analysis (WGCNA) identified the Mitogen-Activated Protein Kinases (MAPK) signaling pathway as responsive to NAA treatment, participating in the formation of LRs in tea plant. This study provides potential signaling pathways for the investigation of LRs formation in tea plant and identifies candidate genes for further research into tea plant root system architecture (RSA).

Ontogenetic correlates, not direct adaptation, explain the evolution of stelar morphology.

The primary vascular system of plants (the stele) has attracted interest from paleobotanists, developmental biologists, systematists, and physiologists for nearly two centuries. Ferns, with their diverse stelar morphology, deep evolutionary history, and prominent fossil record, have been a major focus in studies of the stele. To explain the diversity of stelar morphology, past adaptive hypotheses have invoked biomechanics, hydraulics, and drought tolerance as key selection pressures in the evolution of stelar complexity; but, these hypotheses often isolate the stele from a whole-plant developmental context, ignoring potential covariation between vascular patterning and shoot morphology. Furthermore, incongruence between expected patterns and observed data challenge adaptive hypotheses, precluding a comprehensive explanation of stelar evolution. While ontogeny has been previously recognized as a factor in stelar diversification, it has not been fully integrated into a comprehensive framework. Here we synthesize 150-years of research on stelar morphology, incorporating developmental, physiological, and phylogenetic data to present the ontogenetic hypothesis of stelar evolution. This hypothesis posits that stelar morphology is an integrated feature of whole-plant ontogeny, not a trait shaped by direct selection for adaptive patterns. This shift in perspective provides an updated framework for understanding the determinants of stelar morphology and focusses future efforts to ask more incisive questions about the evolution and function of primary vascular architecture.