Expansion of a localized population of the introduced Stratiotes aloides (Hydrocharitaceae) in Lough Derg, Ireland

An expansion of an introduced female clone of Stratiotes aloides L. (Water-soldier) was located in a delta region on the western side of Lough Derg, Co Galway (v.c.H15), Ireland in 2007. This population was followed over a thirteen-year period. It was initially located at three adjacent sheltered localities, within sweepback bays on either side of an emerging river and within an adjacent canal. The study involved surface observations later supplemented with aerial images. The shallow water conditions, shelter and the presence of Phragmites australis appear to have supported the early establishment by retaining small S. aloides clusters amongst its stems. These clusters later merged to produce a mainly surface expanding monoculture. This enlarged from less than 1 ha to approximately 3.3 ha to occupy much of the sheltered Rossmore Bay area during this study. Flowers were first noticed in 2008, and during subsequent visits, producing infertile seed-pods. Expansion took place with the production of daughter plants. A small nearby population, 1 km to the east, within an unused harbour, did not produce an emergent phase. A small group in a shallow cut, between the two locations, disappeared during the study. Aerial images from different sources were useful to identify the expansion of the emergent stage due to the distinctive bright green coloration of surface leaves. It is unclear how this plant arrived in Lough Derg, but might have been a garden plant release. Small drifting plants, seen during wintertime, may yet colonize other regions within this lake.

WOLFFIA ARRHIZA (L.) HORKEL EX WIMM. RECORDS IN THE NOVOSIBIRSK REGION (WEST SIBERIA) - THE FIRST IN ASIAN RUSSIA

In 2020 the first record of Wolffia arrhiza was registered in Novosibirsk Region (West Siberia) in the floodplain lake. Wolffia arrhiza formed vast stands with an area of hundreds square meters and with high productivity. Besides monodominant communities, it was met as a component of the cenoses of such hydrophytes as Stratiotes aloides , Hydrocharis morsus-ranae , as well as of the helophyte communities formed by Typha latifolia and Eleocharis mamillata . According to local residents, the large stands of Wolffia was observed for some years, thus, most likely, the population winters safely at the latitude of Novosibirsk. The most likely source of Wolffia arrhiza appearance in the lake was a deliberate introduction from the aquarium. Although the probability of this plant entering to the lake from the waste water of the city septic tank of the Novosibirsk sewage waters also exists.

Genetic Diversity of Stratiotes aloides L. (Hydrocharitaceae) Stands across Europe

Intense land use and river regulations have led to the destruction of wetland habitats in the past 150 years. One plant that is affected by the reduction in appropriate habitats is the macrophyte Stratiotes aloides which has become rare in several areas. The preservation of genetic diversity within a species is a prerequisite for survival under changing environmental conditions. To evaluate the level of genetic diversity within and among populations of Stratiotes aloides, we investigated samples from waterbodies across Europe using AFLP. Low genetic diversity among samples from the same population was found, proving that stands consist of few clones which propagate clonally. Nevertheless, most populations showed differences compared to other populations indicating that there is genetic diversity within the species. The analyzed samples formed two groups in STRUCTURE analyses. The two groups can be further subdivided and mainly follow the major river systems. For conserving the genetic diversity of Stratiotes aloides, it would thus be preferable to focus on conserving individuals from many different populations rather than conserving selected populations with a higher number of individuals per population. For reintroductions, samples from the same river system could serve as founder individuals.

ВИДОВИЙ СКЛАД ТА СТАН ПОПУЛЯЦІЙ ЛІКАРСЬКИХ РОСЛИН НА ТЕРИТО-РІЇ ЛУГАНСЬКОЇ ОБЛАСТІ

Наведено результати дослі-дження фітоценозів Луганської області з метою встановлення видового складу лікарських рослин та стану популяцій. Ідентифіковано 304 види. Малочисельними популяціями харак-теризувалися на луках Dracocephalum triflorum L., Stachys palustris L., Tussilago farfara L., Rhaponticum serratuloides (Georgi) Bobrov, Bidens tripartitа L.; на лісових галявинах – Platan-thera bifolia (L.) Rich., Veronica officinalis L., Symphytum officinale L., Vincetoxicum albovianum (Kusn.) Pobed., Hypericum perforatum L., Polygonatum officinale All., Hierochloe odorata Wahid; по берегах водойм – Acorus calamus L., Stratiotes aloides L., Gratiola officinalis L., Iris pseudacorus L.Викликає занепокоєння малочисельність таких видів лікарських рослин, як Veronica officinalis, Iris pseudacorus, Symphytum officinale, Tussilago farfara, які потребують збереження та відтворення.

A monopodial rosette model of shoot formation as a program of secondary-aquatic grasses appearing

On the basis of comparative morphological analysis of the structure of life forms the concept “key biomorph” is offered; it is a mien of a plant which reflects adaptation to the conditions of a definite habitat (a static aspect, a model) and a definite stage in evolutional changes of biomorphs (a dynamical / evolutional aspect). The paper shows a comparative morphological range of key biomorphs in accordance with a monopodial rosette model of shoot formation per gradient of moisture increase in the direction: a floodplain meadow – shores, shore fronts – the water line – a water body. Polygonum bistorta is considered the original key biomorph, changes in it could occur in three lines: 1) Polygonum bistorta – Butomus umbellatus – Nuphar lutea; 2) Polygonum bistorta – Scirpus lacustris – Eleocharis palustris; 3) Polygonum bistorta – Limosella aquatica – Stratiotes aloides. It seems that appearing of secondary-aquatic grasses with a monopodial rosette model of shoot formation was provided by the following modes of morphological evolution: deviation on the shoot level; abbreviation of the bud stage in shoot formation, in forming a part of the shoot (inflorescence), in the anatomic structure of the shoot and the ontogenesis of the original plant; prolongation of the bud phase in shoot development and ontogenesis of the genet.

Water Soldier Stratiotes aloides L.—Forgotten Famine Plant With Unique Composition and Antioxidant Properties

Stratiotes aloides L. is common water plant in central Poland. Due to its expansive character, S. aloides L. can strongly affect the functioning of aquatic ecosystems. S. aloides L. was an important famine plant in central Poland. This plant was commonly collected and cooked until the turn of the 20th century. It has also been used to heal wounds, especially when these are made by an iron implement. The objective of the present work was to study the phenolic profile in the leaves and roots of S. aloides as well as their antioxidant potential and ability to inhibit lipoxygenase (LOX) in the light of their potential bioaccessibility. The dominant compound in its leaves was luteolin-7-O-hexoside-glucuronide (5.84 mg/g DW), whereas the dominant root component was chrysoeriol-7-O-hexoside-glucuronide (0.83 mg/g DW). Infusions from leaves, roots, and their 1:1 (v/v) mixture contained potentially bioaccessible antiradical compounds. S. aloides is a good source of water-extractable reductive compounds. Especially valuable are the leaves of this plant. The roots of S. aloides contained very active hydrophilic compounds able to chelate metal ions. However, their potential bioaccessibility was relatively low. The hydrophilic compounds from the leaves were the most effective XO inhibitors (EC50 = 9.91 mg DW/mL). The water-extractable compounds derived from the leaves and roots acted as uncompetitive LOX inhibitors.

Biomorph Limosella aquatica L. and its contribution in stolon-rosette water grasses formation

The paper presents comparative-morphological analysis of biomorphs Limosella aquatica L., stolon-rosette perennial mesophyte grasses (Viola odorata L.), and yearling vegetative hydrophytes (Stratiotes aloides L. and Hydrocharis morsus-ranae L.). It is shown that L. aquatica is a monopodial growing monocarpic with side stolon-rosette shoots and their systems with up to four branching orders. The primary shoot, as well as rosette parts of stolon-rosette shoots, is made of metamers with foliage leafs, axil complexes with differently sets of constituents: two collateral buds and/or their derivatives: flower buds/flowers/fruit, side stolon-rosette shoots or their systems. At the initial stage the shoot-forming mode of L. aquatica is similar to that of V. odorata: a monopodial rosette one with green assimilating leaves, flowers, and stolon-rosette shoots. But iterative branching of stolon-rosette shoots changes the shoot-forming mode of L. aquatica to a sympodial semirosette as in S. aloides, and especially in H. morsus-ranae. Biomorph L. aquatica combines the features of stolon-rosette perennial mesophyte grasses and stolon-rosette yearling vegetative hydrophytes: stolon-rosette shoot formation from axil buds, iterative branching, collateral buds, reduction inflorescence to one flower (S. aloides). Thus of habit L. aquatica can be viewed as a stage of perennial flower mesophyte plants’ shifting to life in water.

The late Holocene decline of Trapa natans L. in Northern Poland in the light of new palaeobotanical and geochemical data

Trapa natans (water chestnut) is an aquatic, thermophilic plant whose decline has been observed in many localities in central Europe during the last decades. In this paper, we present a description of two new T. natans subfossil sites located outside its present northern distribution in Poland. High-resolution analysis of plant macrofossils supported by geochemical analysis were undertaken to reconstruct the palaeoecological habitat and examine the cause of the late Holocene decline of T. natans that took place ca. 4000 calibrated years before AD 1950 (cal. yr BP) in a paleolake, presently the Bagno Kusowo bog. Its disappearance was a consequence of terrestrialisation and the development of peatland. In paleolake sediments covered by the peat layer in the Mechacz Wielki bog, T. natans macrofossils were found from before ca. 3300 cal. yr BP. The decline of T. natans could have resulted from the changes and development of other plant communities where the dominant role was played by Stratiotes aloides and Nymphaea sp. In our study sites, T. natans occurred together with Potamogeton crispus, Potamogeton obtusifolius, Nymphaea alba, and Nuphar sp. in eutrophic water dominated by Ca2+, Fe3+, and Al3+ ions. Our palaeobotanical and geochemical results align with the contemporary conditions of T. natans habitat.