Utricularia Vulgaris Research Articles

Metal concentrations in aquatic macrophytes as influenced by soil and acidification

Bioavailability of metals to aquatic plants is dependent on many factors including ambient metal concentration, pH of soil or water, concentration of ligands, competition with other metals for binding sites, and mode of exposure. Plants may be exposed to metals through water, air, or soil, depending on growth form. This paper examines the influence of soil type under two regimens of water acidification on metal uptake by four species of aquatic macrophytes: smartweed (Polygonum sagittatum), burreed (Sparganium americanum), pondweed (Potamogeton diversifolius), and bladderwort (Utricularia vulgaris) in constructed, experimentally acidified wetlands. Soil types consisted of a comparatively high-metal clay or a lower-metal sandy loam. Each pond was either acidified to pH ca. 4.8–5.3 or allowed to remain circumneutral. Metal concentrations tended to be higher in the submerged bladderwort and pondweed than in the emergent burreed and smartweed. Soils were important to plant metal concentrations in all species, but especially in the emergents. Acidification influenced plant concentrations of some metals and was especially important in the submerged pondweed. Bioaccumulation of metals occurred for Mn, B, Sr, Ba, and Zn, compared to soil concentrations.

Iridoids and verbascoside in callitrichaceae, hippuridaceae and lentibulariaceae

Callitriche stagnalis (Callitrichaceae), Hippuris vulgaris (Hippuridaceae), Pinguicula moranensis and Utricularia vulgaris (both Lentibulariaceae) have been investigated for iridoid glucosides and verbascoside or similar compounds. Aucubin and/or catalpol were found in all four species and esters of these iridoids were present in three of them. From Utricularia vulgaris were isolated two novel iridoid esters, namely 6- O- p-coumaroylaucubin and 10- O-caffeoylaucubin. Verbascoside was present in Callitriche, Hippuris and Pinguicula, but could not be detected in Utricularia.

Uptake and translocation of prey‐derived 15N and 32P in Utricularia vulgaris L.

summaryThe rootless submerged carnivorous hydrophyte Utricularia vulgaris L. is a potentially useful subject for the quantitative study of foliar nutrient uptake and use, because known quantities of nutrients can be supplied precisely to individual leaves. We report here results obtained by hand‐feeding prey labelled with 15N and 32P to leaves of known age in plants growing in near‐natural conditions.Prey‐derived 15N was rapidly taken up and translocated: in plants fed via 3‐d‐old leaves, about 30% of the prey 1SN appeared in the immature parts of the plant within 2 d. Almost all parts of the plant that were immature at the time of feeding received and retained prey 15N throughout the 20 d experiment. Some backward translocation of 1SN was observed, but only up to the second day after feeding. 32P was also taken up and translocated rapidly, but was not retained by young tissues after they had become mature. Backward translocation of 32P was observed into side‐shoot meristems and flowers arising on parts of the plant older than the fed leaves. This is in contrast to 15N uptake, where side‐shoot buds and flowers received labelled nitrogen only if they arose on parts of the plant younger than the fed leaves.

The developmental plasticity of Utricularia aurea (Lentibulariaceae) and its floats

Utricularia aurea Lour., an Old World aquatic of the section Utricularia, may produce a whorl of floats shortly above the base of the peduncle. If floats are lacking, they are replaced by rhizoids (resembling short shoots with claw-like subunits). A similar plasticity is found with respect to the dissected leaves along the watershoots (stolons), whose axes (rachides) may or may not be inflated. Branching is only axillary in the flowers that are subtended by bracts. Inflorescences and branch watershoots normally originate from supra-axillary positions along the upper stolon sector, i.e. from positions that are associated with the leaves. Thread-like air shoots arise as extra-axillary structures along the upper stolon sector. Morphological and developmental evidence supports the view that leaves, floats and rhizoids, air shoots, watershoots and inflorescences are partially homologous to each other, i.e. equivalent to some degree. These structures may be seen as overlapping morphogenetic pathways that have some but not all developmental processes in common. Utricularia aurea is compared with other members of the section Utricularia in order to find the developmental pattern typical for this section. Hypothetical evolutionary trends are presented for the various species within the section, including Utricularia australis R.Br., Utricularia foliosa L., Utricularia macrorhiza LeConte, Utricularia stellaris L.f., and Utricularia vulgaris L.

Peroxidase activity in lake macrophytes and its relation to pollution tolerance

The metabolic basis underlying pollution-dependent composition of freshwater vegetation was investigated by analyzing peroxidase activity and total glutathione contents. Peroxidase is one of the major enzymes catalyzing oxidative metabolism of xenobiotics in plants. Glutathione-dependent reactions are also crucial in such detoxification processes. Eighteen macrophyte species of Lake Kallavesi (Finland) were studied. Previously, observations based on the distribution of these species in relation to water pollution have been reported. On the basis of such observations ecological ranks had been assigned to the macrophytes. In almost all the true aquatic species (e.g. Callitriche palustris, Elodea canadensis, Potamogeton perfoliatus, Nymphaea candida and Utricularia vulgaris), we observed that tolerance to water pollution, chiefly caused by pulp and paper mill effluents, was consistently related to high peroxidase activities. Species (e.g. Myriophyllum alterniflorum, Ranunculus peltatus, Scirpus acicularis and Isoetes lacustris), sensitive to the above conditions, had low peroxidase activities. A few species (e.g. Phragmites communis and Sparganium simplex) which were observed to have moderately low peroxidase activities and yet had been reported to be indifferent or tolerant to such pollution, had high total glutathione content. Peroxidase activity, especially in true aquatic macrophytes, appeared to be a critical determinant of their tolerance to water pollution caused by pulp and paper mill effluents.

Measuring investment in carnivory: seasonal and individual variation in trap number and biomass in Utricularia vulgaris L.

The partitioning of biomass between traps and leaves is a measure of the investment in carnivory of Utricularia vulgaris and is dependent on the relative values of three attributes: trap size, trap number and leaf size. Marked seasonal and individual variations in trap size, trap number and leaf size occur within a small population of U. vulgaris at Wicken Fen, Cambridgeshire, UK, with some plants consistently having fewer traps per leaf than others, and some smaller leaves than others, throughout the growing season. However, the three attributes vary independently, so that all combinations over the observed ranges of trap size, trap number and leaf size occur simultaneously in the population. In spite of the variation in the three constituent factors, the proportion of biomass invested in traps is close to 50% in the majority of plants and throughout most of the growing season. The contribution of traps to total biomass cannot be predicted from the number of traps per leaf. Although the proportion of biomass represented by traps is the most useful measure of a plant's investment in carnivory, the precise way in which the biomass is partitioned between a variable number of traps of different sizes may also be an important consideration in cost-benefit analyses.

The Size and Shape of Traps of Utricularia vulgaris L.

An individual of the aquatic carnivorous plant Utricularia vulgaris L. simultaneously bears many traps ranging in size from about 1 to 5 mm long. The traps are dimorphic, one type being in the vast majority. The shape, volume and biomass of majority-type traps conform to scaling relationships that allow various attributes of functional and ecological consequence to be predicted from an easily measured length. Trap size is not a reflection of the duration of development or age since maturity of a trap, since each cohort of traps consists of a range of trap sizes, resulting from differential rates of cell division and expansion. The investment of carbon, nitrogen and phosphorus resources in an individual trap scales with biomass such that about 40 small traps can be produced for the same initial outlay as one large one. Larger traps have a wider aperture and much more capacious lumen than small traps, potentially accommodating larger prey and more of them, but it remains to be discovered whether the benefits due to more prey caught by large traps scale to offset the greater costs of production. Key-words: Carnivorous plant, scaling of traps, Utricularia vulgaris

Plant community dynamics in a chain of lakes: principal factors in the decline of rooted macrophytes with eutrophication

Shoe Lake and East Graham Lake, part of a small chain of lakes in southeastern Michigan, USA, differ in nutrient loading and in the structure and productivity of their aquatic plant communities. A comparative study of species frequency and biomass distributions, nutrient contents, and responses to experimental nutrient enrichment and shading, was conducted to determine the principal factors controlling the macrophyte dynamics. A central objective was to address the question of why rooted macrophyte growth declines with eutrophication, and to test existing models designed to explain this phenomenon. In the more eutrophic Shoe Lake, diversity and productivity of rooted macrophytes were relatively low, restricted primarily by combined shading of phytoplankton, periphyton, and non-rooted macrophytes (principally Ceratophyllum demersum, along with Utricularia vulgaris and Cladophora fracta). In the less eutrophic East Graham Lake, lower nitrogen availability restricted the growth of all of these shading components, resulting in clearer water and higher productivity and diversity of rooted macrophytes. The macrophytes did not allelopathically suppress the phytoplankton in East Graham Lake. The results supported a direct relationship between nutrient loading, increasing growth of phytoplankton, periphyton and non-rooted macrophytes, and decline of rooted macrophytes.

Rapid turnover of traps in Utricularia vulgaris L.

Utricularia vulgaris growing at Wicken Fen, England, showed rapid turnover of the trapping apparatus. New groups of leaves, each bearing many traps, were produced at a rate of 1.4-2.8 groups per day from April to September, 1987. Old leaves decayed at a comparable rate, so that individual leaves survived for less than 50 days. In July, trapping efficiency of individual bladders was greatest between 1 and 6 days of age and then declined rapidly. Very few traps more than 19 days old could capture prey and most were lost from the leaves within 32 days. The lifespan of traps was closely related to their size and position on the leaves. Because of the rapidity of changes in trap condition with age, trap age is a vital consideration in any studies of the functional ecology of U. vulgaris.

Comparison of the macrophyte communities of a clearwater and a brownwater oligotrophic lake in Kejimkujik National Park, Nova Scotia

Beaverskin and Pebbleloggitch Lakes are small, proximate, acidic, oligotrophic, headwater lakes located in southwestern Nova Scotia. Beaverskin Lake has clear water, its euphotic zone is deep, and it has extensive beds of macrophytic vegetation that cover most of its bottom to a depth of 6.5 m. In contrast, the water of Pebbleloggitch Lake is highly colored by dissolved humic substances, and macrophytes are restricted to a narrow littoral fringe in depths of less than about 1.8 m. The most widespread macrophyte community in Beaverskin Lake occurs at depths of 2.0–6.5 m and is dominated by Sphagnum macrophyllum and Utricularia vulgaris, while the second most prominent community is littoral and is dominated by Eriocaulon septangulare, Lobelia dortmanna, and Eleocharis acicularis. The most prominent community in Pebbleloggitch Lake is dominated by the floating-leaved Nuphar variegatum rooted as deep as 1.8 m, while communities dominated by E. septangulare and Sphagnum spp. occur in water less than about 0.7 m deep.

Evaluation of the emergence method in estimating seed bank composition of prairie wetlands

Bottom samples were collected in each of two semi-permanent prairie marshes in Stutsman County, North Dakota, to determine the accuracy of the seedling emergence method in assessing seed-bank composition. Samples were divided into two equal portions and placed under moist and submerged soil conditions in the greenhouse. Emerged seedlings were identified and counted. To check the results of this technique, a portion of the field samples were sieved and seeds were isolated and identified. The seedling emergence method was generally accurate in determining wetland seed bank composition. The same five species ( Scirpus spp., Chenopodium rubrum L., Typha spp., Rumex maritimus L., and Ranunculus sceleratus L.) accounted for 92.6% and 93.4% of the total number of seedlings and seeds, respectively. The rank-order of all species was also significantly correlated between methods. Only Utricularia vulgaris L. failed to germinate well in the emergence flats (0.13% emerged seedlings versus 3.19% isolated seeds). Providing conditions in the submerged-soil treatment that are more conducive to the germination of open water species would improve the method. A modification of the flotation method used for separating seeds in recommended in wetlands with relatively large seeds.

Choice of perch by the water stick insect

Several characteristics of an adequate perch site for the water stick insect, Ranatra linearis L. (Heteroptera: Nepidae) and variations of perch preference during post-embryonic development have been investigated. Under laboratory conditions adults preferred reeds ( Calamagrostis epigeros and Phragmites communis ) to the other plant species presented and avoided rushes ( Juncus sp.). These results confirmed Waitzbauer's (1976) observations that showed that Ranatra preferred Phragmites communis over Utricularia vulgaris in the field. During development, preference for one type of plant changed first from Lemna to Elodea , then after the 4th instar, from Elodea to reeds. Predator size in relation, to perch size did not appear to be the main factor influencing these changes of preference. Perch colour preference changed during development from green to brown. In addition, adults preferred vertical perches to horizontal ones, but approximately as many 1st and 2nd instar larvae were found on vertical perches as on horizontal ones. Renatra usually perched parallel to their support: in the majority of observations the longitudinal axis of the body formed an angle of between − 5° and + 15° with the vertical plane at all developmental stages.

Aquatic plants of acid lakes in Kejimkujik National Park, Nova Scotia; floristic composition and relation to water chemistry

To document the aquatic flora of acid lakes in Kejimkujik National Park, N.S., the presence and abundance of aquatic macrophytes growing in water deeper than 3 dm were recorded in 20 lakes. Of the 45 species found, the most important were Sphagnum macrophyllum, Eriocaulon septangulare, Utricularia purpurea, Scirpus subterminalis, Pontederia cordata, Nuphar variegatum, Nymphaea odorata, Eleocharis acicularis, Sparganium angustifolium, Potamogeton confervoides, Lobelia dortmanna, Potamogeton epihydrus, and Utricularia vulgaris. To explore the relationship between floristic composition and water chemistry, information on 12 chemical variables and colour was related to species presence–absence using a nonparametric test based on relative neighbourhood graphs. Analyses of variance (ANOVAs) using chemical data and six groups suggested by a conditional clustering of the species presence–absence data demonstrated significant heterogeneity in Ca, pH, and HCO3. Furthermore, these three proved to be highly correlated. A canonical variate analysis of the six groups revealed one significant axis and separated the lakes into two major groups, characterized by relative acidity. An ANOVA of these two groups established that colour was also significant. There were fewer species in the more acidic (range 8–20, average 15) than in the less acidic lakes (range 15–32, average 22).

Hydrology, development, and biogeochemistry of ombrogenous peat bogs with special reference to nutrient relocation in a western Newfoundland bog

Ombrogenous bogs differ fundamentally from other peatlands in their hydrology, and this affects peat accumulation and bog development as well as the elemental concentrations in peat and water. In oceanic and northern parts of the raised bog zone, the surface of the bog center remains below the critical profile of the water mound because factors other than moisture supply limit its maximum height. In the surface peat, Na and K decrease with depth, whereas other elements increase to a greater or smaller extent. Most elements occur in surprisingly low concentrations below the anaerobic level. In an ombrotrophic bog in western Newfoundland, Na, Mg, and Ca concentrations of bog water were 5, 4–5, and 0.5 times higher, respectively, than in precipitation. K and Mg increased downslope, especially in spring, but not during the vegetation season. In July and August, 20–30% of the Mg, 75–80% of the K, and 93% of the Ca are removed from the precipitation while the water seeps over the bog. Uptake by vegetation is primarily responsible, but Ca is mostly adsorbed on the peat. Increased water flow, rather than higher nutrient concentration, appears to account for the occurrence of more nutrient-demanding species, such as Nymphaea odorata and Utricularia vulgaris, in the pools of the lower slope.

Glycolipids of turions and leaves of Utricularia vulgaris at different stages of development

Turions of Utricularia vulgaris L. were germinated in long‐day conditions at 15°C for 1,3 and 6 days and their glycolipid composition was compared with that of resting but vernalized turions. Digalactosyldiacylglycerides (DGDG), monogalactosyldiacylglycerides (MGDG) and cerebrosides were present at all stages of development. No great changes were found in the glycolipid classes during sprouting but some differences were noted in the proportions of fatty acids. The most common fatty acids in all three glycolipid classes studied were 16:0, 18:0 and 18:2. MGDG and DGDG also contained relatively much 18:3 and its proportion increased during germination. Young turions and full‐grown leaves collected from nature contained the same glycolipid classes as the sprouting turions. The developmental stage of the organs studied is reflected in the fatty acid composition of DGDG and MGDG but is not so evident in the cerebrosides. The 18:2 fatty acid is rather typical of the resting turions, especially in DGDG.

Status of aquatic macrophytes in an undrained area of fen in the Norfolk broads, England

The aquatic macrophyte vegetation of dykes and pools in an area of undrained fen in Broadland, Norfolk, is analysed and described. Three main types of vegetation have been identified, an Elodea-Potamogeton crispus community, a Ceratophyllum-Stratiotes community and a Utricularia vulgaris community. The first two normally occur near the land margins of the fens and the last mainly on deep peat in the central areas. Most luxuriant macrophyte growth was observed at the fen margins where levels of nitrate-nitrogen, derived from land drainage, were higher (both in the water and sediments) than in the central fen areas. Preliminary comparisons are made of some chemical characteristics of the water and sediments of sites with a well developed macrophyte vegetation with others where macrophytes are very poorly developed, or completely absent. Sites poor in macrophytes had higher levels of sodium in the water and sediments and also more strongly reducing sediments than those with a rich macrophyte vegetation. However, measured levels of dissolved inorganic nitrogen and soluble reactive phosphorus were lower, or not significantly different. A recent reduction in the amount of Stratiotes aloides in some dykes may possibly be related to nutrient impoverishment rather than enrichment.

Roles of endogenous and exogenous growth regulators in dormancy of Utricularia vulgaris

The roles of endogenous and exogenous growth regulators on dormancy control of Utricularia vulgaris were investigated by extraction and bioassay of endogenous levels of four classes at various developmental stages and by measuring the effects of synthetic regulators on these stages. The bioassays used were oat coleoptile for auxins, abscisic acid and other inhibitors; lettuce hypocotyl for gibberellins; and soybean callus for cytokinins. Two weeks before turion formation and during innate dormancy abscisic acidlike and bound gibberellinlike levels were high while free gibberellinlike and auxinlike levels were low. Abscisic acid exogenously applied to actively growing plants rapidly induced turion formation even under noninductive environmental conditions. Kinetin rapidly and completely caused sprouting in innately dormant turions but would not promote continued vegetative growth. These plants formed new turions within 2 weeks of sprouting. During imposed dormancy, when turions rapidly sprouted, there was a low level of abscisic acidlike inhibitor and high levels of gibberellinlike and auxinlike compounds. Turions collected during this state could be maintained in a dormant condition by incubation with abscisic acid even at high temperatures which normally induce sprouting. During sprouting the endogenous growth regulator pattern was similar to that described for imposed dormancy. A model of the environmental and growth regulator factors which control dormancy is presented.

Turions and dormancy states in Utricularia vulgaris

Phenology and states of dormancy of Utricularia vulgaris were studied using plants and turions collected at intervals throughout the growing season of 1977 from a shallow eutrophic pond in central Alberta located at 53°25′ N, 113°46′ W. States of dormancy and the effects of photoperiod and temperature were determined by the potential for sprouting and subsequent apical growth under long-day (18 h, 20 °C), short-day (12 h, 20 °C), and high-temperature (16 h, 30 °C) conditions, with and without varying periods of chilling at 2–3 °C. Physiological changes associated with different states of dormancy such as frost hardiness, starch content, and dark respiration were also investigated. Turions were formed 1 month after summer solstice and entered a state of innate dormancy during which only a high-temperature treatment at 30 °C would induce sprouting. Plants from innately dormant turions that were forced to sprout and were then cultured at 20 °C invariably reentered dormancy by the production of new turions. Turions collected in the late stages of innate dormancy could withstand −8 °C but not −12 °C. As temperatures dropped and ice cover became continuous, turions entered an imposed state of dormancy during which immediate sprouting and continued vegetative growth occurred under all conditions. Starch content reached a maximum of 49 mg g−1 fresh weight during early innate dormancy and declined steadily thereafter. Dark respiration in response to temperature of plants obtained from turions collected during innate and imposed dormancy states differed above 25 °C but was similar below.

Habitat selection by dabbling ducks in the Baie Noire marsh, southwestern Quebec

We monitored the waterfowl distribution in a recently flooded 260-ha marsh along the Ottawa River during 1974 and 1975. The birds (the three most important species were the black duck. Anas rubripes; the mallard, A. platyrhynchos; and the blue-winged teal, A. discors) did not distribute randomly among the five major habitats recognized, but clearly preferred a habitat dominated physiognomically by broken cattail (Typha angustifolia) cover but best characterized ecologically by ivy-leaved duckweed (Lemna trisulca), whitish water-milfoil (Myriophyllum exalbescens), and common bladderwort (Utricularia vulgaris). On average, broods (0.3/ha) and adult birds (6.6/ha) were four times more abundant per hectare there than in the next best habitat. This pattern of use was stable throughout the summer and throughout the daylight period as well. Multivariate analysis (correspondence factor analysis) enabled us to extract those ecological variables that played a determinant role in controlling plant distribution throughout the marsh. The observational and analytical techniques developed in this work could be applied to the development of marsh management plans designed to promote the expansion of the preferred waterfowl habitat.

Capture Enhancement in a Carnivorous Aquatic Plant: Function of Antennae and Bristles in Utricularia vulgaris

Traps of the carnivorous hydrophyte Utricularia vulgaris Linnaeus (Lentibulariaceae) have structures termed antennae and bristles around their trapdoors that increase their rate of entrapment of the substrate-dwelling prey Chydorus sphaericus (Chydoridae, Crustacea). The kind and number of these structures are important in determining capture rate. Experimental data and corresponding behavioral observations support Darwin's hypothesis that antennae and bristles function as a "funnel" leading potential prey toward the trapdoor and their capture by offering the prey a favorable substrate that exploits their natural locomotor and feeding behavior.