Free-floating Aquatic Plant Research Articles

Evaluation of the Phytoremediation Potential of Aquatic Plants and Associated Microorganisms for the Cleaning of Aquatic Ecosystems from Oil Products

Phytoremediation of oil pollution using free-floating aquatic plants is a promising method for water body cleaning. In this study, the influence of Eichhornia crassipes and Pistia stratiotes on the degradation of oil pollution was investigated. The loss of oil alkanes and the rheological characteristics of water were evaluated, and an analysis of the emerging rhizospheric microbial communities was carried out using high-throughput sequencing. The presence of E. crassipes and P. stratiotes plants in oil-contaminated tanks had no effect on the degradation of oil alkanes. However, the presence of plants promoted the development of rhizospheric bacteria capable of growing in oil-contaminated environments. Alpha diversity of microbial communities in oil-contaminated samples was higher in the presence of plants. Additionally, plants significantly reduced the water/oil interfacial tension, which facilitated the availability of hydrocarbons for biodegradation. A difference was noted in the microbiome between E. crassipes and P. stratiotes. Changes in the composition of microbial communities highlight the potential of E. crassipes and P. stratiotes as rhizospheric hosts for microorganisms in the phytoremediation of water bodies.

Qualitative and GC-MS analysis of medicinally potent aquatic herb Pistia stratiotes L. Assam, India

Pistia stratiotes L. belongs to Araceae family, is a free-floating aquatic plant found in rivers, lakes, and ponds It is commonly known as water cabbage or water lettuce. P. stratiotes stands out as a prominent Ayurvedic remedy, extensively utilized over time for treating a multitude of ailments, The present study was aimed to carry out the detailed preliminary phytochemical and GC-MS analysis of the leaves and root of P. stratiotes. The preliminary phytochemical analysis of P. stratiotes indicated the presence of alkaloids, carbohydrades, reducing sugars, glycosides, flavonoids, phenolic, tannins, triterpinoids, saponins, proteins and amino acids. GC-MS analysis was also carried out to detect the phytoconstituents present in the methanolic, hexane and ethylacetate extract of leaves and root of P. stratiotes.

Accumulation Assessment of Mo4+, Pb++, and Cu++ in the Acidic Water of Copper Mines with Lemna minor and Lemna gibba

Pollutants accumulate in aquatic habitats due to mining activities. The duckweed family includes water plants such as Lemna gibba and Lemna minor, which are tiny, delicate, free-floating aquatic plants. L. minor and L. gibba were used in this study to examine the accumulation capacities of Mo4+, Pb++, and Cu++ in acidic fluids from copper mining. Two reactors were assigned to L. gibba and L. minor, respectively. These plants and the reactor water were gathered daily for 8 days. Acid mine water pH, temperature, and electric conductivity were also tested daily. L. gibba and L. minor were cleaned, dehydrated, and burned in a drying oven for a whole day at 300 °C. ICP-MS (inductively coupled plasma mass spectroscopy) was used to determine the Mo4+, Pb++, and Cu++ content of the plant and water samples. The Mo, Pb, and Cu concentrations in the copper mining acidic fluids were 30 ± 4, 260 ± 12, and 15,535 ± 322 μg L−1, respectively. Regarding Mo, Pb, and Cu extraction from copper mining acidic fluids, L. gibba and L. minor performed more efficiently than control samples, gathering 29 and 177 times more Mo, 30 and 109 times more Pb, and 495 and 1150 times more Cu, respectively. Considering these findings, L. gibba and L. minor are good plants for rehabilitating polluted waters and can efficiently remove Mo, Pb, and Cu from acid mine fluids.

Inactivation of phosphorus in a highly eutrophic pond using Zeofixer® to eliminate the free-floating aquatic plant (Spirodela polyrhiza)

Free-floating aquatic plants are important invasive alien species whose excessive growth strongly affects freshwater ecosystems and their ecological service functions worldwide. Due to their rapid reproduction rate and the difficulty in their removal using common methods, the management of these aquatic weeds is still challenging. In this study, we proposed a strategy to control giant duckweed (Spirodela polyrhiza) in a highly eutrophic pond by blocking the supply of phosphorus by greatly lowering the phosphorus concentration in water using Zeofixer®, a novel lanthanum-containing P-inactivation agent. We found that the application of Zeofixer® satisfactorily eliminated the aquatic weed from the study pond. Zeofixer® had a high affinity for phosphate with a maximum adsorption capacity of 21.19 mgP/g, and it reduced the concentration of dissolved inorganic P, which was the major form of P species in the pond, from 1.60 to 0.005 mg/L. Amendment of pond sediment with Zeofixer® greatly diminished the P concentration in water under either oxic or anoxic conditions, although the latter caused a great release of P from sediment when compared with the former. After Zeofixer® treatment, the releasable P fractions in the sediment were substantially converted to stable P fractions, enabling the inactivation of P and the retardation of future P release. In conclusion, the free-floating aquatic plants in bodies of water could be thoroughly and permanently controlled using P-inactivation agents.

Preliminary study on the man-made habitat of Utricularia gibba L. in the tropical peatland environment

Utricularia gibba L. is a free-floating aquatic carnivorous plant found in some parts of the world, including Asian tropical regions. However, data on water’s physical and chemical properties for the ecology of this species in Asian tropical peatland environments are underrepresented in the literature. Here, we reported water physical and chemical properties for the habitat of U. gibba occurring in the tropical peatland of Kalimantan Barat, Indonesia. The study site is on the man-made water canal in Jalan Parit Haji Muksin II, Kubu Raya Regency, Kalimantan Barat. We measured temperature, electrical conductivity (EC), Total Dissolved Solid (TDS), pH, Dissolved Oxygen (DO), total nitrogen, total phosphorus, nitrates, and nitrite of the waters at three points along the water canal where the bladderworts occur. The results showed that U. gibba inhabits waters with low conductivity (< 66 µS cm-1), low TDS (< 32 ppm), acidic (< pH 6), low DO (< 8 mg L-1), but higher total nitrogen (7.02 – 19.4 mg L-1), total phosphorus (0.86 – 1.71 mg L-1), nitrates (3.01 – 4.06 mg L-1) and nitrite (3.53 – 5.18 mg L-1). These findings demonstrate that U. gibba in tropical peatland environments reportedly occurs in acidic (pH 5.03 – 5.29) but relatively high nutrient habitats compared to its counterpart and other species found elsewhere.

Azolla rubra R.Br. (Salviniaceae) on Rēkohu / Wharekauri / Chatham Island

Azolla rubra (Salviniaceae) is reported from the Chatham Islands for the first time based on chance finds made in February and April 2023 from two lakes in the north-eastern portion of Rēkohu / Wharekauri / Chatham Island (hereafter Rēkohu). The biostatus of Azolla on the islands is reviewed and it is believed that plants are more likely to have arrived naturally via fragments bought to the islands by waterfowl from Aotearoa / New Zealand than by other means, so should be treated as indigenous. We advise that the impact of Azolla on the most sheltered, shallow, freshwater bodies of the islands should be monitored, as hitherto the islands waterbodies have been mostly devoid of free-floating aquatic plants.

Distribution and Bioresource Potential of Duckweed (Lemna minor L.) in Maiduguri, Nigeria

Lemna minor L. (Arales: Lemnaceae) is a small, delicate, free-floating aquatic plant that grows mostly in a nutrient-enriched environment. It has wide applications in agriculture and biosciences. This study evaluated the physicochemical factors affecting the distribution, biomass, and proximate composition of L. minor in waterways within Maiduguri metropolis, northeastern Nigeria. Duckweeds were sampled with a quadrat (25 × 25 cm) along imaginary transect lines from different areas of the metropolis between the early hours of 9:00 and11:00 a.m. in December 2021. Some physicochemical parameters of the sites were measured. Proximate composition and biomass were determined. Principal component analysis (PCA) indicated that PC1, PC2, and PC3 explained 79.2% of the variation. The strongest positive correlations were between Mg and alkalinity, while K, Mg, alkalinity and TSS were negatively correlated. Proximate composition indicated 11.4-18.21% crude protein and 45.92-48.47% carbohydrate in the samples. Bray-Curti’s index indicated that duckweeds in the Custom area and Bolori were the most similar (0.99). Samples collected from the Unimaid area recorded the highest wet biomass (5.0 ± 0.2 g/m2), while a sample from Umarari was the lowest (2.24 ± 0.1 g/m2). The physicochemical parameters of the site provided suitable factors for laboratory culture and large-scale production. The findings provide baseline data on the ecology and potential of duckweed as a cost-effective source of crude protein (CP) and other essential nutrients for aquaculture and animal feed, as well as a model plant for aquatic ecology, the environment and biotechnological research. Further studies to explore the applications of L. minor in different fields were recommended.

Utilization of Water Hyacinth as Organic Fertilizer on Kemaro Island, Palembang City

The water hyacinth is a free-floating aquatic plant. Water hyacinth has massive reproductive capacity, which causes several problems, including ecosystem destruction, irrigation problems, and its use as a breeding ground for mosquitoes, which causes the mosquito population to increase. The high growth rate of water hyacinth is also a major problem faced by the people on Kemaro Island. The large number of water hyacinth plants on Kemaro Island causes environmental issues, such as slum settlements. Pupuk Sriwidjaja Palembang (Pusri) Ltd. is here to overcome this problem through a community empowerment program, namely the Sehat Sejahtera Program (Sesera). The methods used in this research are literature study, observation, and interviews. The research results show that the Sesera Program is able to reduce the number of water hyacinths that accumulate around the residences of Kemaro Island residents. Through the Sesera Program, Pusri empowers the community to utilize and process water hyacinth in order to reduce the number of water hyacinth growing around Kemaro Island. Activities carried out by utilizing water hyacinth to become compost. To maintain these impacts or benefits, the Sesera Program through water hyacinth composting activities needs to involve other stakeholders who are able to encourage and increase the impact of the program, such as the Village Government, City government, and agriculture service.

Progress in the utilization of water hyacinth as effective biomass material

AbstractWater hyacinth (Eichhornia crassipes) is considered a prospective free-floating aquatic plant potentially used to address current issues on food, energy, and the environment. It can grow quickly and easily in various tropical and subtropical environments as long as it has access to adequate light and water to support photosynthetic growth. Ecosystems are threatened by their invasive growth and remarkable capacity for adaptation. However, managing this plant can result in valuable products. This paper demonstrates particle technologies that might be used to utilize water hyacinths, including brake pads, fertilizer, bioenergy, animal feed, phytoremediation agents, bioplastics, and adsorbents. This study is accompanied by a discussion based on the conducted experiments and currently available literature, providing readers with a clearer understanding. Water hyacinth's capacity to absorb macro- and micro-nutrients, nitrogen, and phosphorus makes it a good plant for phytoremediation. The prospect of producing cellulose makes it prospective as a biomass energy source and livestock feeding. Further, it can be transformed into high-cellulose content particles for applications in bioplastics, brake pads, and adsorbents. The current reports regarding education of water hyacinth to student also were added. Finally, issues and suggestions for future development related to the use of water hyacinths are discussed. This study is expected to provide comprehensive knowledge on how to turn invasive water hyacinth plants into valuable products.

Impact of Low Lithium Concentrations on the Fatty Acids and Elemental Composition of Salvinia natans.

The photosynthetic pigments, protein, macro and microelements concentrations, and fatty acids composition of Salvinia natans, a free-floating aquatic plant, were analyzed after exposure to Hoagland nutrient solution containing 1, 3, and 5 mg/L Li. The Li content of Salvinia natans grew exponentially with the Li concentration in the Hoagland nutrient solution. The exposure to Li did not induce significant changes in Na, Mg, K, Cu, and Zn content but enhanced the Ba, Cr, Mn, Ni and Mo absorption in Salvinia natans. The most abundant fatty acids determined in oils extracted from Salvinia natans were C16:0, C18:3(n6), C18:2(n6), and C18:3(n3). The photosynthetic pigments did not change significantly after exposure to Li. In contrast, chlorophyll and protein content decreased, whilst monounsaturated and polyunsaturated fatty acids content increased after the exposure to 1 mg/L Li. The results indicated that Salvinia natans exposed to low Li concentrations may be a good source of minerals, omega 6 and omega 3.

Assessing phytotoxicity of microplastics on aquatic plants using fluorescent microplastics.

Although studies on microplastics are increasing every year, still very little is known about their toxicity. Especially for plant species, even studies of uptake of microplastics are only few, not to mention phytotoxicity of microplastics. Therefore, we conducted a pilot study on the phytotoxicity of 1-μm-sized fluorescent microplastics (FMPs) on the free-floating aquatic plants Spirodela polyrhiza and Salvinia natans and the emergent aquatic plant Phragmites australis using 0.1% and 0.01% FMP treatment. Furthermore, uptake of FMPs by plants was verified by detecting fluorescence of FMPs by laser. A free-floating aquatic plant S. polyrhiza and emergent aquatic plant P. australis showed significantly decreased harvested biomass after 3weeks indicating phytotoxicity of FMPs, but S. natans did not show any differences of harvested biomass or chlorophyll contents among treatments. Detection of fluorescence from plant leaves provided evidence of active FMPs uptake by plants. The emission spectra of plant leaves in 0.1% FMP treatment showed similar peaks to those of free fluorescent microplastics, providing a firm evidence of FMPs uptake by plants. This study is one of the pioneering studies to explore fluorescent microplastic uptake and toxicity in aquatic plants and therefore provides a baseline for further studies.

Geographical distribution of floating aquatic plants in relation to environmental conditions in southern Quebec, Canada

Communities of free-floating aquatic plants dominated by Lemnaceae (duckweeds) are common in ponds and wetlands globally with important ecological functions. In addition to the cosmopolitan common duckweed (Lemna minor), other species of Lemnaceae, liverworts (Ricciaceae), hornworts (Ceratophyllum), and water ferns (Salviniaceae) often coexist over broad geographic areas. Despite these species all sharing a similar mode of life and resource requirements, they have important morphological and physiological differences such as variation in body size, degree of morphological reduction, presence/number of roots, and position in the water column. The degree to which these differences play a role in shaping their distributions is, however, unclear. We report a field survey of floating aquatic plants in southern Quebec, Canada. We find that species distributions are influenced by habitat specialization to water phosphorus levels. High nutrient specialization followed a continual reduction in body size and morphological complexity, with smaller, simpler species found in higher nutrient sites. We also found a latitudinal gradient in species richness with more northerly sites supporting less diversity. Rare species did not show clustering suggesting that dispersal limitation was not an important factor in determining local abundance. Our results suggest that the distribution of these plants is in part driven by competitive sorting of suitable species from a regional species pool.

Enzymatic hydrolysate of water hyacinth with NaOH pretreatment for biobutanol production via ABE fermentation by Clostridium beijerinckii JCM 8026

Water hyacinth (WH; Eichhornia crassipes) is an invasive and free-floating aquatic plant that is rapidly spreading over the world causing various environmental problems. The utilization of WH as a feedstock for biofuel production is a challenging solution to overcome the environmental problem as well as address the energy shortage. Due to the complex structure of lignocellulosic materials, pretreatment is an inevitable step to maximize the sugar yield before being used as a substrate in fermentation. The aim of this study was to investigate the utilization of WH for biobutanol production via acetone-butanol-ethanol fermentation by Clostridium beijerinckii JCM 8026. The WH was pretreated with sodium hydroxide (NaOH) at various concentrations [0, 2, and 4% (w/v)], reaction times (30, 60, and 90 min), and temperatures (80, 100, and 120 °C). The pretreatment results were optimized using response surface methodology with a Box-Behnken design and Minitab software analysis. The maximum total sugar concentration (21.05 g/L) following cellulose digestion was obtained after a 2% (w/v) NaOH for 90 min at 100 °C. This hydrolysate slurry gave a subsequent butanol concentration, yield, and productivity of 2.09 g/L, 0.15 g/g, and 0.012 g/L/h, respectively, following C. beijerinckii JCM 8026 fermentation. To help understand the effect of the pretreatments, changes in the pretreated samples were observed by surface area analyses, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis.

Effect of water hyacinth (Eichhornia crassipes) plant into water bodies and its composite materials for commercial applications

Water Hyacinth ( Eichhornia crassipes) is a free-floating aquatic plant that is commonly found in local water bodies. Its quick emergence and rapid expansion are the main advantages, allowing it to cover entire water surfaces. The government considers the plant to be waste and has invested a significant amount of money to remove it from water bodies. This paper provides a brief overview of the effective use of water hyacinth in wastewater treatment, converting it into WH fiber. By utilizing the water hyacinth fiber and an epoxy matrix, a WH composite is produced. The hyacinth fiber reinforced composite samples attained 27.06 MPa tensile strength and 43.51 MPa flexural strength, and 1.25 J impact strength. Water hyacinth plant presented water bodies water level parameters are tested with the help of the suitcase method. Essential tests, such as mechanical testing, thermal behavior, and characterization techniques (XRD, FTIR, SEM, optical microscope inspection, and water and chemical absorption tests), are conducted. In conclusion, the results suggest that the water hyacinth plant could be better utilized in the production of commercial household applications and lightweight materials in the field of natural fiber composites.

Removal of Ag, Au, and As from Acid Mine Water Using Lemna gibba and Lemna minor—A Performance Analysis

Mining activities result in the accumulation of pollutants in aquatic environments. This study aimed to investigate the accumulation performances of Ag, Au, and As using Lemna minor and Lemna gibba in the acid mine waters of Maden copper deposit. L. minor and L. gibba are aquatic plants belonging to the duckweed family. They are small, fragile, and free-floating aquatic plants. L. minor and L. gibba were separately placed into two reactors. The plants and water from the reactors were collected daily for eight days. Additionally, the electric conductivity, temperature, and pH of the acid mine water were measured daily. L. minor and L. gibba samples were washed, dried, and burned at 300 °C in a drying oven for 24 h. The water and plant samples were analyzed for Ag, Au, and As content using ICP-MS (Inductively Coupled Plasma Mass Spectroscopy). The acid mine waters of Maden copper deposit contained 9.25 ± 0.4, 0.92 ± 0.02, and 193 ± 12 μg L−1, Ag, Au, and As, respectively. In comparison to control samples, L. gibba and L. minor showed high and effective performances in removing Ag, Au and As from the acid mine waters of Maden copper deposit; 240 and 174 times for Ag; 336 and 394 times for Au; and 30 and 907 times for As, respectively. Overall, the results suggest that L. gibba and L. minor can effectively remove Ag, Au, and As from acid mine waters, highlighting their potential use in environmental remediation.

Endophytic microbiota of floating aquatic plants: recent developments and environmental prospects.

Plant-associated microorganisms play a critical role in plant survival and functional attributes. There are many studies on the taxonomical and functional aspects of microorganisms associated with terrestrial plants. However, the microbiome of aquatic plants is not much explored. This work details the studies on microbiomes and diversity in microbial communities inhabiting the three common free-floating aquatic plants of tropical regions viz. duckweed, water hyacinth and water lettuce, widely implicated for their bioremediation potential. Studies conducted till date reveal the prevalence and dominance of different Bacillus sp. Other genera, including Rhodanobacter, Pseudomonas, Rhizobium, Achromobacter, Serratia, Actinobacteria, Proteobacter, Klebsiella and Acidobacteria, have also been prominently reported. This lesser explored niche offers great bioprospecting opportunities to obtain taxonomically diverse and functionally distinct microorganisms. Bacterial endophytes from these aquatic plants have been primarily studied for their ability to produce indole acetic acid and degrade phenol. Limited studies reveal some fungal endophytes to have promising herbicidal effect. Not much is known on other functional attributes and hence microbial studies on these plants holds much promise for obtaining novel isolates or isolates with novel functions that would impact both aquatic and terrestrial ecosystems. This study proposes the need for exploring the role of endophytes as biocontrol agents and their potential to provide a pragmatic and robust solution to the aquatic weed menace in freshwater bodies. Bioprospecting of this lesser studied ecological niche hence is a promising field of research that has both environmental and economic potential.

American frogbit response to herbicides

Limnobium spongia (frogbit) is a free-floating aquatic plant that can produce extensive floating mats causing negative ecological, social, and economic impacts that can harm aquatic fauna (i.e., dissolved oxygen depletion) and restrict human uses of water. Literature describing effective control measures for frogbit is minimal. Efficacy of high and low doses of seven foliar-applied herbicides (2,4-D, florpyraux-ifen-benzyl, flumioxazin, glyphosate, imazamox, imazapyr, and triclopyr) were evaluated in a mesocosm setting in the summers of 2018, 2020, and 2021. Both emergent and submersed frogbit biomass were reduced at least 99% by imazamox (0.56 and 1.11 kg ai ha􀀁1) and imazapyr (0.42 and 0.84 kg ae ha􀀁1) 8 wk after treatment (WAT) compared with nontreated reference plants. Triclopyr (6.71 kg ae ha􀀁1) reduced frogbit biomass 92% and flumioxazin (0.42 kg ai ha􀀁1) reduced biomass 87 to 93% compared with reference plants. 2,4-D (2.12 and 4.24 kg ae ha􀀁1), glyphosate (2.83 and 5.67 kg ai ha􀀁1), triclopyr (3.36 kg ae ha􀀁1), florpyrauxifen-benzyl (0.02 and 0.05 kg ai ha􀀁1), and flumioxazin (0.21 kg ai ha􀀁1) did not reduce frogbit biomass 8 WAT compared with reference plants. Future research should consider the efficacy of different herbicide combinations to control frogbit, as well as the role of diluent volume per unit area, especially with imazamox and imazapyr. Field studies also will be useful in determining whether the results observed in this study will translate to management of frogbit in natural settings.

Investigation on Suitability and Safeness of Water hyacinth for Animal Feed, from Lake Ziway

Water hyacinth is a free-floating aquatic plant native to the Amazon Basin in South America and the most dangerous and worst aquatic plant in the world including Ethiopia. The objective of the current study was to evaluate water hyacinth found in Lake Ziway for its suitability and safe as animal feed. Suitability of the water hyacinth was determined based on its nutrient content, while safety was determined based on the level of selected heavy metals, and pesticides. Three sites were selected for sampling purposively based on the types of land use and potential sources of water pollution around the Lake. Water hyacinth samples were collected from the selected sites and the level of selected heavy metals, 21 organochlorine, and 14 organophosphate pesticides were analyzed using atomic absorption spectrometry and Gas Chromatography-Mass Spectrometry (gc-ms), respectively. The proximate analysis in the water hyacinth were also determined using the standard method of analysis. The results obtained demonstrate that the level of heavy metals found the ranged from nd to9.0 mg/Kg for cadmium; nd to 30.44 mg/Kg for chromium; 118.1 to 518.8 mg/Kg for manganese; 6.78 to 57 mg/Kg for copper; 34.28 to 884.19 mg/Kg for iron; 2.84 to 37.02 mg/Kg for nickel nd to 21mg/kg for lead and 25.67 to 89.9 mg/Kg for zinc. All pesticides levels were below the limits established by European council regulation for plants used as animal feed which is &lt;0.001mg/Kg. The proximate analysis of the water hyacinthsamples of the leaves parts was moisture content 9.32%, crude protein 18.03%, crude fat 1.42%, crude ash 17.04%, crude fiber 31.04% carbohydrate 22.30%and energy 174 Kcal. The result of the stem revealed the presence of 3.96 moisture content, 2.17% crude protein, 0.47% crude fat, 5.23% crude ash, 6.70% crude fiber, 81.47% carbohydrate, and 338.79 Kca energy. Based on the results of this study, water hyacinth in the Lake Ziway can be potentially used for animal feed.

Lithium Accumulation in Salvinia natans Free-Floating Aquatic Plant.

The new context of the intensive use of lithium-based batteries led to increased production of Li and Li-containing wastes. All these activities are potential sources of environmental pollution with Li. However, the negative impact of Li on ecosystems, its specific role in the plants’ development, uptake mechanism, and response to the induced stress are not fully understood. In this sense, the Li uptake and changes induced by Li exposure in the major and trace element contents, photosynthetic pigments, antioxidant activity, and elemental composition of Salvinia natans were also investigated. The results showed that Salvinia natans grown in Li-enriched nutrient solutions accumulated much higher Li contents than those grown in spring waters with a low Li content. However, the Li bioaccumulation factor in Salvinia natans grown in Li-enriched nutrient solutions was lower (13.3–29.5) than in spring waters (13.0–42.2). The plants exposed to high Li contents showed a decrease in their K and photosynthetic pigments content, while their total antioxidant activity did not change substantially.

Pace and shape of senescence in three species of duckweed.

Senescence is progressive bodily deterioration associated with declines in survival and fecundity in older age classes. There is great diversity in patterns of senescence across species, but these patterns can be difficult to compare formally due to variation in the absolute time scales in which species live and die: members of some species live for a matter of days, others for millennia. To address this issue, the “pace‐shape” approach was developed to decouple absolute time from analyses and instead standardize life history traits in terms of average life expectancy, facilitating intra‐ and interspecific comparisons. Here, we use this approach to distinguish the generic form of demographic trajectories (shape) from the time scale on which the trajectories occurred (pace) in three species of tiny, free‐floating aquatic plants known as duckweeds (Lemna gibba L., L. minor L., and L. turionifera Landolt), which have mean lifespans of less than a month under typical lab conditions, and exhibit age‐related declines in survivorship and reproduction. Using a randomized block design in which we tracked a final total of 430 individuals, we report differences in pace and shape among the three species. Specifically, the largest, least‐fecund, and typically longest‐lived species, L. gibba, tended to exhibit more rapid decreases in time‐standardized survivorship and fecundity compared with the other two species. This study emphasizes variation in aging patterns that can be found among plant species, including those in the same genus, and provides further validation for the utility of applying the pace and shape approach in interspecific comparisons.