Vukotić et al. 2022, Biologica Nyssana 13(1) 13 (1) September 2022: 59-81 DOI: 10.5281/zenodo.7117592 Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Original Article Danica Vukotić Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18 000 Niš, Serbia Faculty of Electronic Engineering, University of Niš, Aleksandra Medvedeva 14, 18106 Niš, Serbia danica.vukotic@elfak.ni.ac.rs (corresponding author) Dragana Jenačković Gocić Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18 000 Niš, Serbia Dušica P. Ilić Faculty of Electronic Engineering, University of Niš, Aleksandra Medvedeva 14, 18106 Niš, Serbia Danijela Nikolić Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18 000 Niš, Serbia Vladimir Ranđelović Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18 000 Niš, Serbia Received: July 19, 2022 Revised: September 20, 2022 Accepted: September 28, 2022 Abstract: At the end of summer 2021, phytocenological research was conducted on aquatic and wetland vegetation of the Pusta River - left tributary of the South Morava River. Using UPGMA classification method and the Bray-Curtis distance on a set of 97 relevés and 44 species, degree of floristic differentiation between studied vegetation plots was quantified. It was established that 7 associations take part in composing vegetation of the Pusta River – Myriophyllo-Potametum Soó 1934, Potametum nodosi Soó (1928) 1960, Segal 1964, Phragmitetum australis Savič 1926, Typhetum latifoliae Nowiński 1930, Glycerio-Sparganietum neglecti Koch 1926, Phalaridetum arundinaceae Libbert 1931 and Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950. The plant associations of vegetation class Potamogetonetea Klika in Klika et Novák 1941- Potametum nodosi and Myriophyllo-Potametum, are floristically the poorest and entirely consist of native plant species. The associations of vegetation class Phragmito-Magnocaricetea Klika in Klika et Novák 1941 - Typhetum latifoliae (34 taxa), Glycerio-Sparganietum neglecti (33 taxa), Phragmitetum australis (24 taxa) and Phalaridetum arundinaceae (20 taxa) consist of higher number of species, including invasive plants. Vegetation class Bidentetea Tx. Et al. ex von Rochow 1951 is represented by only one association - Polygono-Bidentetum tripartitae, which consists of 24 taxa, with a share of 16.67% of allochthonous species. Collected phytocenological data are going to be good basis for the future research of the vegetation of lotic ecosystems in the southern Serbia. Key words: aquatic and wetland vegetation, Pusta River, UPGMA classification Apstrakt: Vodene i močvarne biljne zajednice Puste reke (Južna Srbija): sintaksonomska pripadnost i florističke karakteristike Krajem leta 2021. godine, sprovedena su fitocenološka istraživanja vodene i močvarne vegetacije Puste reke – leve pritoke Južne Morave. Korišćenjem UPGMA klasifikacione metode i Bray-Curtis-ove distance nad setom podataka od 97 fitocenoloških snimaka i 44 vrsta kvantifikovan je stepen florističke diferencijacije između proučavanih sastojina. Ustanovljeno je da u izgradnji biljnog pokrivača Puste reke učestvuje 7 biljnih zajednica - Myriophyllo- Potametum Soó 1934, Potametum nodosi Soó (1928) 1960, Segal 1964, Phragmitetum australis Savič 1926, Typhetum latifoliae Nowiński 1930, Glycerio-Sparganietum neglecti Koch 1926, Phalaridetum arundinaceae Libbert 1931 i Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950. Asocijacije vegetacijske klase Potamogetonetea Klika in Klika et Novák 1941 - Potametum nodosi i Myriophyllo-Potametum, su floristički najsiromašnije i u potpunosti izgrađene od autohnotnih biljnih vrsta. U sastav zajednica vegetacijske klase Phragmito-Magnocaricetea Klika in Klika et Novák 1941 - Typhetum latifoliae (34 vrste), Glycerio-Sparganietum neglecti (33 vrste), Phragmitetum australis (24 vrste) i Phalaridetum arundinaceae (20 vrste) ulazi veći broj vrsta, uključujući i invazivne biljne vrste. Vegetacija klase Bidentetea Tx. Et al. ex von Rochow 1951 predstavljena je zajednicom Polygono-Bidentetum tripartitae izgrađenom od 24 vrsta, sa udelom alohtonih vrsta od 16.67%. Prikupljeni fitocenološki podaci predstavljaju svojevrsnu osnovu za buduća, intenzivnija istraživanja biljnog pokrivača lotičkih ekosistema južne Srbije. Ključne reči: vodena i močvarna vegetacija, Pusta Reka, UPGMA klasifikacija © 2022 Vukotić et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially under the same license as the original. 59 14th Symposium on the Flora of Southeastern Serbia and Neighboring Regions Introduction Macrophytes are a complex group of plants adapted to the life in water. They include all aquatic vascular plants and aquatic mosses, and some authors also include macroscopic algae (Stevanović & Janković, 2001). They form aquatic plant communities that, compared to terrestrial communities, consist of a smaller number of species and, in most cases, are dominated by one species. Macrophytes can be both submerged and floating, and can be further divided into morphoecological types of plants that are rooted and those that are not rooted, but whose roots float in water, or these types of plants don’t develop roots at all (Stevanović & Janković, 2001). Communities of rooted, floating plants as well as submerged macrophytes belong to the vegetation class Potamogetonetea Klika in Klika et Novák 1941, while floating, non-rooted macrophytes of relatively still and nutrient-rich waters, belong syntaxonomically to the vegetation class Lemnetea O. de Bolòs et Masclans 1955 (Mucina et al., 2016). Aquatic vegetation in Serbia has been previously studied in lentic systems (Vukov et al., 2003; Topuzović et al., 2009; Stanković et al., 2009, Ranđelović & Zlatković, 2010; Marković et al., 2015), while in the lotic systems it has been studied only in a few rivers and channels (Stojanović et al., 2007; Vukov et al., 2008; Jenačković et al., 2010; Ljevnaić-Mašić, 2010; Džigurski et al., 2016). Wetland vegetation belongs to the class Phragmito-Magnocaricetea Klika in Klika et Novák 1941 (Mucina et al., 2016). In contrast to aquatic vegetation, the structure and physiognomy of phytocenoses in wetlands is determined by emergent macrophytes. This type of vegetation develops in places where water dries out during the summer months but remains close to the ground surface, as well as in habitats that are flooded throughout the year (Ranđelović et al., 2007a). Wetland vegetation provides refuge for many species, often rare and endangered, that inhabit only habitats where wetland vegetation is present. They are considered very sensitive and one of the most endangered habitats in the world, and their degradation is continuous and uncontrolled (Svitok et al., 2011). Wetland vegetation in Serbia has been studied mainly in the plains of Vojvodina (Slavnić, 1956; Vukićević et al., 1966; Babić, 1971; Stojanović et al., 1987; Butorac & Crnčević, 1987; Parabućski & Butorac, 1994; Polić, 2006; Stojanović et al., 2007; Ljevnaić-Mašić, 2010; Džigurski et al., 2010; Džigurski et al., 2011), while it has been less researched in the southern parts of Serbia (Katić, 1910; Košanin, 1910; Mišić et al., 1987; Ranđelović, 1978; Ranđelović & Zlatković, 2010; Jenačković et al., 2010; Jenačković, 2017; Jenačković et al., 2019). Aquatic and wetland vegetation show high floristic and ecological similarity, which is why they are often studied together. These types of vegetation on the South Morava River and its tributaries have not been sufficiently investigated in terms of their floristic composition and ecological differentiation. Wetland vegetation south of the Autonomous Province of Vojvodina was examined near Vlaško polje (Jovanović, 1958), in the valley of the Velika Morava River (Jovanović, 1965), near Kragujevac (Veljović, 1967), in the valley of the Južna Morava River (Ranđelović, 1988), in the Moravica River (Milenović & Ranđelović, 2005), in the Batušinačke swamps located to the left of the South Morava River (Ranđelović et al., 2007a), on the banks of the Murina River, Brestovac (Ranđelović et al., 2007b), also on the banks of Vlasina Lake, Cvetkova River, Dedina Dolina (Ranđelović & Zlatković, 2010), in the Svrljiški and Beli Timok rivers (Jenačković et al., 2010), Smilovsko Lake, Krupac Lake, Oblačina Lake, wetland habitats in surroundings of the cities of Bela Palanka and Prokuplje, as well as near the villages of Žitkovac, Vrtište, Medoševac, Lepaja, Bresničić, Lalinac and Levosoje which have been investigated by Jenačković (2017). Aquatic vegetation was also investigated in the Beli and Svrljiški Timok rivers (Jenačković et al., 2010). The classification of aquatic and semi-aquatic vegetation of lakes in Serbia was also carried out by Laketić (2013), as well as the review of complete aquatic vegetation studied so far in Serbia (Cvijanović et al., 2018). The main objectives of this paper are to determine: • the diversity of aquatic and wetland phytocenoses of the Pusta River, • the degree of floristic differentiation among the communities, • the syntaxonomic affiliation of the registered communities. Materials and Methods Research area Phytocenological research was conducted on the aquatic and wetland vegetation of the Pusta River along its course from the municipality of Bojnik to the municipality of Doljevac (Fig. 1). The Pusta River is located in the southern part of Serbia and is a left tributary of the South Morava River. The river’s spring is located near the village of Donji Statovac. It is 71 km long and its catchment is 569 km2. It flows into the South Morava River near the village of Pukovac (Gavrilović & Dukić, 2002). Phytocenological research of aquatic and wetland communities was conducted during September 2021, 60 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation 61 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation as this part of the vegetation season is considered optimal for their sampling (Jenačković et al., 2019). Phytocenological relevés were recorded in the lower course of the Pusta River, from its confluence with the South Morava River to the municipality of Bojnik, along a river length of about 35 km. The largest number of phytocenological relevés were recorded in the part of the river stream near the villages of Pukovac and Kočane, as in these localities the phytocenoses of aquatic and wetlands were fully developed. In the part of the river course between the village of Pukovac and the municipality of Bojnik, the areas with wetland vegetation were drastically reduced. The wetland phytocenoses were represented only by a few smaller patches of vegetation plots that were several kilometers apart. The cleaning of the riverbed significantly destroyed the wetland vegetation in Bojnik, which is believed to have developed in the riparian zone. The phytocenological surveys were carried out according to the principle of the Swiss-French Braun-Blanquet school (Braun-Blanquet, 1964). The areas of the sampled stands had a standard size of 4 m2 for aquatic vegetation and 16 m2 for wetland vegetation. Sampling points were georeferenced using the GPS device (Global Positioning System). The plant material collected in the sampled stands was deposited in the herbarium collection “Herbarium Moesiacum” of the Faculty of Natural Sciences and Mathematics (HMN) of the University of Niš. The determination was performed with the help of dichotomous identification keys: “Flora SR Srbije I-X” (Josifović, 1970-1980, Sarić, 1986, 1992), “Флора на НР Българияˮ (Йорданов, 1963- 1986, Велчeв, 1989), and “Flora Europaea” (Tutin et al., 1964-1980). The nomenclature and taxonomy of plant species were standardized according to the Euro+MedPlantBase database (https://www. emplantbase.org). Nomenclature of syntaxa, at the level of vegetation classes, orders and alliances was standardized according to Mucina et al. (2016). The names of associations, and their syntaxonomic positions, have been adjusted with Tzonev (2009), Cvijanović (2018) and Landucci et al. (2020). Statistical analyses The TURBOVEG software package was used to digitize 97 phytocenological relevés recorded during field research (Hennekens & Schaminée, 2001). Classification analysis was performed using the UPGMA (Unweighted pair group method with arithmetic mean) classification method and the Bray-Curtis similarity index. The value of the “Crispness of Classification” (Botta-Dukát et al., 2005) was used to determine the optimal number of clusters. Groups of phytocenological relevés belonging to one or more associations, identified by the hierarchical classification analysis as a separate group (cluster), are characterized by diagnostic species. Diagnostic species were determined based Fig. 1. Map of the investigated area on the Pusta River, start point (Bojnik) and end point (Doljevac) 62 on the phi-coefficient, which expresses the degree of taxon fidelity to a particular cluster (Chytrý et al., 2002). In addition, virtual standardization of all vegetation groups was performed to eliminate the dependence of the phi-coefficient on the size of the vegetation groups – clusters (Tichý & Chytrý, 2006). Fisher’s accuracy test was used to exclude all phi-coefficient values that were not statistically significant at the significance level p<0.05. Species with a phi-coefficient greater than 0.20 were considered as diagnostic species, while species with a phi-coefficient greater than 0.50 were considered as highly diagnostic species. In addition to the classification analysis, where the optimal number of clusters was determined, one more cluster analysis was performed to better understand the floristic similarity between individual phytocenological relevés. Second cluster analysis was performed without determining the optimal number of clusters. The dominant and constant species were determined for the vegetation groups identified using the results of the classification analysis. Dominant species were determined by calculating the average cover values in relevés within the groups using the cover index (Ic) (Lausi et al., 1982) and the share in total cover (D%) (Surina, 2005). Dominant species were determined to be those that were present in at least 10% of the relevés with a cover of at least 25%. Constant species were considered those that occurred in at least 40% of the relevés within the clusters. The determination of diagnostic, constant and dominant species within the clusters, as well as the determination of the optimal number of clusters during classification analysis, were performed using the software package JUICE 7.0 (Tichý, 2002, http://www.sci.muni.cz/botany/juice). The software package JUICE 7.0 was also used to create the BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation combined synoptic table. The combined synoptic table contains information about the floristic composition of the studied communities and the quantitative proportion of species in each of them. Results and discussion Based on the results of the classification analysis, with determined optimal number of clusters (Fig. 2) and the composition of the diagnostic species within the clusters defined (Tab. 1), four main vegetation groups (clusters) were distinguished. The results of classification analysis, performed without determining optimal number of clusters, are presented in Fig. 3, and illustrate the floristic similarities between individual relevés more clearly. Based on the results of these analyses, it can be noticed that cluster II (Fig. 2) is clearly divided into 3 subclusters (Fig. 3), and cluster IV (Fig. 2) into 2 subclusters (Fig. 3), resulting in 7 vegetation groups that participate in the construction of the plant cover of the investigated part of the Pusta River. The first cluster (Fig. 2) corresponds with relevés of Typhetum latifoliae Nowiński 1930 (Fig. 3), second one (Fig. 2), divided into 3 subclusters (Fig. 3), unifies relevés of Phalaridetum arundinaceae Libbert 1931, Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950 and Glycerio-Sparganietum neglecti Koch 1926, third cluster corresponds with relevés of Phragmitetum australis Savič 1926, and fourth, divided into two subclusters, unifies relevés of Potametum nodosi Soó (1928) 1960, Segal 1964 and Myriophyllo-Potametum Soó 1934. Classification analysis showed that the greatest floristic similarity exists between the clusters I and II, i.e., the communities Typhetum latifoliae Nowiński 1930 (cluster I) and Phalaridetum arundinaceae Libbert 1931, Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950 and Glycerio-Sparganietum Fig. 2. Dendrogram obtained as a result of the hierarchical UPGMA classification on Bray-Curtis resemblance matrix along with determining optimal number of clusters. 63 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Table 1. The combined synoptic table with the information on frequency and phi-coefficient values (x100) for species occurring in four optimal cluster groups defined by UPGMA classification analysis. The values for the frequency are represented by the base, while the values for fidelity are given in the form of superscripts Species Clusters I II III IV Typha latifolia L. 100 85.6 14 11 . Salix alba L. 50 31.3 33 22 . Sparganium erectum L. 16 91 69 22 8 Lythrum salicaria L. 62 77 42.8 22 . Mentha aquatica L. 16 47 42.1 11 . Polygonum mite Schrank 22 37 29.8 11 . Phalaris arundinacea L. 6 28 40 . . Tanacetum vulgare L. 3 21 24.7 11 . Phragmites communis Trin. . . 100100 . Urtica dioica L. 25 26 56 37.9 . Echinocystis lobata (Michx.) Torr. & A. Gray 3 2 33 46.1 . Robinia pseudoacacia L. 6 9 33 37.2 . Myriophyllum spicatum L. 6 19 . 92 79.9 Potamogeton nodosus Poir. 16 28 11 85 60.4 Bidens tripartitus L. 47 47 56 . Polygonum lapathifolium L. 28 25 22 . Salix euxina I. V. Belyaeva 31 21 33 . Xanthium strumarium L. 28 35 11 . Populus sp. 16 9 11 . Epilobium hirsutum L. 12 12 11 .. Lycopus europaeus L. 9 21 22 Rubus caesius L. 6 12 22 . Galium aparine L. 6 9 11 . Potamogeton crispus L. 3 2 . 15 Lemna minor L. 3 7 . 8 Calystegia sepium (L.) R. Br. 19 23 . . Leersia oryzoides (L.) Sw. 12 19 . . Solanum dulcamara L. 12 19 . . Amorpha fruticosa L. 9 9 . . Echinochloa crus-galli (L.) P. Beauv. 3 9 . . Humulus lupulus L. 9 . 11 . Rumex conglomeratus Murray 3 2 . . Lysimachia vulgaris L. 3 2 . . Erigeron canadensis L. . 5 11 . Scutellaria galericulata L. . 5 . . Aristolochia clematitis . 2 . . Chenopodium album L. . 2 . . Lathyrus latifolius L. . 2 . . neglecti Koch 1926 (cluster II). Cluster IV differs the most as this cluster consists of associations Potametum nodosi Soó (1928) 1960, Segal 1964 and Myriophyllo-Potametum Soó 1934 presenting aquatic vegetation (Fig. 2). Association Typhetum latifoliae is characterized by presence of highly diagnostic species - Typha latifolia (Tab. 1). It is floristically rich, includes 34 taxa, and its constant species are Lythrum salicaria, Salix alba and Bidens tripartitus (Appendix 1). The stands of this community have been developed in the coastal zone, where T. latifolia has been partly in the water and borders with the stands of Myriophyllo- Potametum and Potametum nodosi (Fig. 4). On the banks of the river, it forms a dense, impassable cover, and is intersected in some places by the Glycerio-Sparganietum neglecti. In southern part of Serbia, stands of this association were recorded in the Batušinačke swamps (Ranđelović et al., 2007a), on the banks of the Grlište hydro-accumulation (Stanković et al., 2009), Vlasina Lake (Ranđelović & Zlatković, 2010). In Ribinac, the stands in which Typha latifolia is the dominant species together with Phragmites communis were recorded (Ranđelović et al., 2007b). The spectrum of accompanying species is diverse and depends on the habitat. According 64 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation to Šumberová (2011), short-term floodplains are usually much richer in the number of taxa and include not only common wetland plants (e.g. Lycopus europaeus L. and Lythrum salicaria L.) but also tall sedges (e.g. Carex riparia Curtis) and species typical for meadow vegetation (e.g. Equisetum palustre L., Galium palustre L. and Symphytum officinale L.). In long-term floodplains, especially in highly eutrophic wetlands, the macrophyte Lemna minor L. is common (Šumberová, 2011), which is also recorded in the studied stands of the Pusta River. It is necessary to stress that high values of phi- coefficient for species Salix alba (Tab. 1) is related with including one relevé characterized by high percentage value of cover of Salix alba in database. On the territory investigated, Salix alba occurs frequently within stands of the Typhetum latifoliae, at its upper border or at the elevated parts of the bank where it occurs mainly with one or two individuals. In some places, one to two individuals of Salix alba can be found due to the lack of wetland vegetation. Salix alba represents the remnants of once-present floodplain forests that developed near the Pusta River. Today, the remains of flooded forests in the lower course of the river, are represented only by certain species of the genus Salix and Populus, some Fig. 3. Dendrogram obtained as a result of the hierarchical UPGMA classification on Bray-Curtis resemblance matrix without identifying optimal number of clusters Species Clusters I II III IV Scrophularia nodosa L. . 2 . . Berula erecta (Huds.) Coville . 2 . . Stellaria neglecta (Lej.) Weihe . 2 . . Eleocharis palustris (L.) R. Br. . 2 . . Stachys palustris L. 3 . . . Althaea officinalis L. 3 . . . 65 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation of which extend into the wetland vegetation. The stands of Phalaridetum arundinaceae (Fig. 4) have been developed on the raised banks of the riverbed, exposed only to occasional floods, after which the surface water stagnates for a short time. The diagnostic species of this association is Phalaris arundinacea, while the constant species are Mentha aquatica, Lythrum salicaria, Sparganium erectum, Salix alba and Xanthium strumarium. It is floristically rich and consists of 20 taxa (Appendix 2). This plant community Fig. 4. The stands of associations Typhetum latifoliae Nowiński 1930 (1,2), Phalaridetum arundinaceae Libbert 1931 (3), Phragmitetum australis Savič 1926 (4), Glycerio-Sparganietum neglecti Koch 1926 (5) and Potametum nodosi Soó (1928) 1960, Segal 1964 (6) developed in riverbed and on the banks of Pusta River, as well. occurs in habitats with pronounced fluctuations of the flood level. The development is conditioned by the hydrological regime of groundwater along the river course (Ranđelović & Zlatković, 2010). It is present in nutrient rich habitats, on sandy-gravelly to clay substrates. With its strong organic production, this community contributes to the overgrowth of ponds and shallow depressions (Panjković, 2005). Sometimes it occurs in deeper depressions where shallow (<0.3 m) surface water is retained during most of the growing season (Jenačković, 2017). 66 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Phalarietum arundinaceae is only fragmentarily developed in several localities in southern Serbia. According to Ranđelović et al. (2007b), the best developed stands are along the Šaranica stream near the villages of Brestovac, Pukovac and Bubanj, in the valleys of the Vlasina River and Murina River. Also, stands of this association were recorded on seasonally flooded habitats near the villages of Gornje Međurovo, Levosoje, Podvis, Vrtište and Žitkovac (Jenačković et al., 2017). Association Polygono-Bidentetum tripartitae consists of 24 taxa (Appendix 3). Its dominant species are Polygonum lapathifolium and Bidens tripartitus (Appendix 3). Since there are only three vegetation plots, a large number of constant species is noticeable, with a proportion of 16.67% of allochthonous species. This community develops on the banks of the river, where the water occasionally floods the banks, and retreats during the summer months. It is widespread in places along the banks of the Pusta River especially where wetland vegetation is absent. Also, this community was phytosociological described in Svrljiški Timok River and Beli Timok River, where it had a similar species composition (Jenačković et al., 2010). Similar floristic composition was recorded in nitrophilous stands developed on the shores of artificial lakes placed near the city of Tuzla (Barudanović & Kamberović, 2011). Glycerio-Sparganietum neglecti is floristically rich association (33 taxa) (Appendix 4) and develops on the banks of the river, in the form of narrow belts, some of which extend into the riverbed, and some on slightly elevated banks (Fig. 4). Its diagnostic and, at the same time, dominant species is Sparganium erectum, while the constant species of association are Lythrum salicaria and Bidens tripartitus. Native species have the largest share in the composition of this phytocenosis, but invasive, non-native species such as Echinocystis lobata, Echinochloa crus-galli, Amorpha fruticosa and Robinia pseudacacia (Lazarević et al., 2012) were also recorded. A few years ago, in the part of the Pusta River which flow through the village of Pukovac and suffering strong anthropogenic influence via discharge of waste water, the stands of this association were phytocoenological described (Jenačković, 2017). Stands recorded in Svrljiški Timok River and Beli Timok River (Jenačković et al., 2010), whose the most common species are Sparganium erectum and Mentha aquatica, show a remarkable floristical similarity with the stands developed in the Pusta River. So far, communities with domination of Sparganium erectum have been recorded in the Batušinačke swamps (Ranđelović et al., 2007a), on suitable habitats near the village of Bubanj (Ranđelović, 1988), Žitkovac, Vrtište, Prokuplje, Gornje Međurovo, Podvis, Rgošte, Levosoje (Jenačković et al., 2019) and on the banks of Vlasina Lake (Ranđelović & Zlatković, 2010) and Smilovsko Lake (Jenačković et al., 2019). The stands of the association Glycerio-Sparganietum neglecti Koch 1926 are frequently involved in the establishment of the plant cover of lowland rivers, not only in our country, but also in the other European countries (Gecheva et al., 2013). The dominant species of this community – Sparganium erectum, is considered a reliable bioindicator of eutrophic waters (Schneider & Melzer, 2003), which explains the frequent occurrence of its monodominant communities in the lower reaches of the river, where high concentrations of nutrients, especially nitrogen, accumulate and are maintained as a result of anthropogenic influence. Sparganium erectum shows exceptional frequency in the studied rivers of Bulgaria, where it occurs in no less than 80 of 223 studied sites, with a frequency of 35% (Gecheva et al., 2013). The taxa Sparganium erectum and Typha latifolia show ecological preferences for wetlands with similar physicochemical properties. They find optimal growing conditions in habitats characterized by relatively deep, slightly acidic water with low electrical conductivity. They prefer habitats where the substrate has the following characteristics: low pH, low values of conductivity values and concentration of carbonates, bicarbonates and potassium (Jenačković, 2017). On the area investigated, stands of Phragmitetum australis (Fig. 4) develops on the highest parts of the riverbanks, often along the road. They have been recorded in only 9 localities in the villages of Kočane and Pukovac. This community is floristically rich and consists of 24 taxa (Appendix 5), and its highly diagnostic species is Phragmites communis (Tab. 1). In addition to the species Phragmites communis, high values of phi-coefficient were established for the species Urtica dioica, Echinocystis lobata and Robinia pseudoacacia. These values probably reflect reduced substrate moisture and increased concentrations of nutrients, primarily nitrogen. Abundant presence of individuals of Echinocystis lobata and Robinia pseudacacia can be explained by their high invasive capacity (Lazarević et al., 2012). Often, in nature, stands of Phragmitetum australis are bordered to the stands of Typhetum latifoliae. They usually prefer mineral sand, mineral-organic, as well as organic substrate (Pełechaty, 1999). In terms of water depth and degree of soil moisture, they successfully develop on diverse habitat types - completely flooded, occasionally flooded and non-flooded. According to Jenačković (2017), dominant species of association Phragmitetum 67 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation australis shows affinities to the habitats with high values of substrate pH. Stands of Phragmitetum australis are widespread in the central Balkans. In Serbia, they have been recorded in the Velika Morava River (Jovanović, 1958; Veljović, 1967), on the slopes of Stara Planina (Mišić et al., 1987), in the South Morava basin (Ranđelović, 1988), in the Toplica River (Perišić et al., 2003), on the shores of Vlasina Lake (Ranđelović & Zlatković, 2010), Smilovsko Lake, Oblačina Lake, near the villages of Žitkovac, Lalinac, Vrtište, Rgošte and Levosoje, on habitats placed in suburb of the city of Bela Palanka (Jenačković et al., 2019). Otherwise, the communities Phragmitetum australis, Typhetum latifoliae and Glycerio-Sparganietum neglecti belong to the phytocenoses that most frequently overgrow the wetland habitats of the central Balkans (Jenačković, 2017). The stands of the Myriophyllo-Potametum develop in the riverbed itself and form a relatively stable submerged community, consisting mainly of rooted hydrophytes (Myriophyllum spicatum and Potamogeton crispus) and floating hydrophytes (Lemna minor). The association develops on a muddy waterbed at depths of up to 2 m, forming a dense cover. In some parts of the Pusta River, the stands of this association form small, separated groups which look like islands composed of plants, while in other parts of the stream they cover the entire water surface from one bank to the another. They prefer slow to moderately slow water flow, but they also tolerate strong water strikes, and are indicators of mesotrophic and eutrophic waters. The association is floristically poor and consists of 3 taxa (Appendix 6). Myriophyllum spicatum is the highly diagnostic species (Tab. 1), while the status of constant species have Potamogeton nodosus and Potamogeton crispus (Appendix 6). Study conducted on the aquatic vegetation of rivers in Slovenia (Germ et al., 2021) have shown that Myriophyllum spicatum and Potamogeton nodosus are the most common aquatic species in undisturbed aquatic ecosystems, while investigation of Slovakian rivers have confirmed that the highest relative mass in rivers has Myriophyllum spicatum (Hrivnak et al., 2006). The species Myriophyllum spicatum, Potamogeton crispus and Lemna minor have taken part in composing aquatic vegetation of the Svrljiški and Beli Timok rivers (Jenačković et al., 2010), river systems and channels in the northern part of Serbia (Radulović et al., 2010; Vukov et al., 2012; Džigurski et al., 2016; Vukov et al., 2017) as well. Otherwise, Myriophyllum spicatum and Potamogeton nodosus are indicators of eutrophic waters (Schneider & Melzer, 2003), which explains their occurrence in the lower parts of the river, where high nutrient concentrations accumulate and remain. Potametum nodosi develops in the riverbed itself, mainly along the coast, and partly invades coastal vegetation where water flow is slower. In deeper parts of the riverbed, however, the community borders with Myriophyllo-Potametum. The highly diagnostic species of this community is Potamogeton nodosus (Tab. 1), and the constant species is Myriophyllum spicatum (Appendix 7). The community is relatively species-poor and is composed of only 4 taxa (Appendix 7). A similar floristic composition have had stands developed in the Svrljiški and Beli Timok rivers (Jenačković et al., 2010). Floristically, this community is also described in the Moravica River, highlighting rare and endangered species (Ljevnaić-Mašić et al., 2016). The stands noted in the Danube-Tisa-Danube Canal in Vojvodina, in the northern part of Serbia, have had a slightly richer floristic composition compared to the stands recorded in Pusta River (Džigurski et al., 2016). It is known that both, wetlands and aquatic vegetation, have developed over the years on the once disturbed river. Since the vegetation along the entire course of the river has never been described completely so far, but only sporadically, we do not have the possibility to compare the data. What is certain is that this area has been disturbed several times and has changed due to the needs of agriculture. Nowadays, the river is surrounded on all sides by fields and arable land, and thus exposed to constant anthropogenic influences. The previously described associations belong to the following vegetation classes, orders and alliances: Potamogetonetea Klika in Klika et Novák 1941 Potamogetonetalia Koch 1926 Potamogetonion Libbert 1931 Myriophyllo-Potametum Soó 1934 Potametum nodosi Soó (1928) 1960, Segal 1964 Phragmito-Magnocaricetea Klika in Klika et Novák 1941 Pragmitetalia communis Koch 1926 Phragmition communis Koch 1926 Phragmitetum australis Savič 1926 Typhetum latifoliae Nowiński 1930 Glycerio-Sparganietum neglecti Koch 1926 Phalaridetum arundinaceae Libbert 1931 Bidentetea Tx. Et al. ex von Rochow 1951 Bidentetalia Br.-Bl. et Tx. Ex Klika et Hadač 1944 Bidention tripartitae Nordhagen ex Klika et Hadač 1944 Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950 68 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Conclusions Based on the results of the classification analyses and composition of diagnostic species per clusters, 7 associations - Typhetum latifoliae Nowiński 1930, Phalaridetum arundinaceae Libbert 1931, Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950, Glycerio-Sparganietum neglecti Koch 1926, Phragmitetum australis Savič 1926, Potametum nodosi Soó (1928) 1960, Segal 1964 and Myriophyllo-Potametum Soó 1934, are described on the territory researched. The stands of Typhetum latifoliae Nowiński 1930 are abundantly developed in the part of the flow from the confluence of the Pusta River to South Morava River all the way upstream to the village of Pukovac, where they are the most developed and occupies the largest recorded area on the Pusta River. The stands of Glycerio-Sparganietum neglecti Koch 1926 were developed in some places along the whole studied part of the river, and they were mainly developed 2-3 km upstream from the village of Pukovac. The stands of Phalaridetum arundinaceae Libbert 1931, Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950, Phragmitetum australis Savič 1926, diverse in size, occur sporadically. In the village of Pukovac and a few kilometers upstream, the aquatic vegetation is more abundantly developed and in some places forms a dense cover that covers the entire water surface. This is one of the first complete research of this kind conducted on the Pusta River, and it represents a good basis for future research on the vegetation of lotic ecosystems in Southern Serbia. Acknowledgements. This work has been supported by the Ministry of Education, Science and Technological Development of Republic of Serbia (Grant No. 451-03- 68/2022-14/200102 and No. 451-03-68/2022-14/200124). References Babić, N. 1971: Močvarna i livadska vegetacija Koviljskog rita. Zbornik Matice srpske za prirodne nauke, 41: 19-87. Barudanović, S., Kamberović, J. 2011: Weed vegetation on the shores of artificial reservoirs of surface mining pits in the area of Tuzla. Herbologia, 12(3): 1-14. Botta-Dukát, Z., Chytrý, M., Hájková, P., Havlová, M. 2005: Vegetation of lowland wet meadows along a climatic continentality gradient in Central Europe. Preslia, 77: 89-111. Braun-Blanquet, J. 1964: Pflanzensoziologie, Grundzüge der Vegetationskunde 3rd ed. Springer, Berlin. 631 p. Butorac, B., Crnčević, S. 1987: Zajednice Acoreto- Glycerietum Slavnić 56 i Sparganio-Glycerietum fluitantis Br.-Bl. 25 na području jugozapadnog Banata. Zbornik Matice srpske za prirodne nauke, 72: 169-184. Chytrý, M., Tichý, L., Holt, J., Botta-Dukát, Z. 2002: Determination of diagnostic species with statistical fidelity measures. Journal of Vegetation Science, 13: 79-90. Chytrý, M., Tichý, L. 2018: National vegetation classification of the Czech Republic: a summary of the approach. Phytocoenologia, 48(2): 121–131. Cvijanović, D. L., Lakušić, D., Živković, M., Novković, M., Anđelković, A., Pavlović, D., Vukov, D. M., Radulović, S. 2018: An overview of aquatic vegetation in Serbia. Tuexenia, 38: 269–286. Džigurski, D., Knežević, A., Stojanović, S., Nikolić, L., Ljevnaić-Mašić, B. 2010: The vegetation of canal Novi Sad - Savino Selo. Thaiszia - Journal of Botany, 20: 137-145. Džigurski, D., Knežević, A., Nikolić, L., Ljevnaić- Mašić, B. 2011: Emergent vegetation in the main canals of the HS DTD in the region of Bačka. Contemporary agiculture, 60(1-2): 73-79. Džigurski, D., Nikolić, L., Ljevnaić-Mašić, B. 2016: Vegetation of the Hydrochari-Lemnetea and Potametea classes in the Danube-Tisza-Danube Hydrosystem (Serbia). Contemporary Problems of Ecology, 9(3): 329–341. Gavrilović, L., Dukić, D. 2002: Reke Srbije. Zavod za udžbenike i nastavna sredstva, Beograd. 218 p. Gecheva, G., Yurukova, L., Cheshmedjiev, S. 2013: Patterns of aquatic macrophyte species composition and distribution in Bulgarian rivers. Turkish Journal of Botany, 37(1): 99-110. Germ, M., Janež, V., Gaberščik, A., Zelnik, I. 2021: Diversity of Macrophytes and Environmental Assessment of the Ljubljanica River (Slovenia). Diversity, 13(6): 278. Hennekens, S., Schaminée, J. 2001: TURBOVEG, a comprehensive data base management system for vegetation data. Journal of Vegetation Science, 12: 589-591. Hrivnak, R., Otahelova, H., Jarolimek, I. 2006: Diversity of aquatic macrophytes in relation to environmental factors in the Slatina river (Slovakia). Biologia, 61(4): 413-419. Jenačković, D., Dimitrijević, D., Ranđelović, V. 2010: Macrophytic flora and vegetation of the rivers 69 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Svrljiški and Beli Timok (Eastern Serbia). Biologica Nyssana, 1(1-2): 23-26. Jenačković, D. 2017: Fitocenološko-ekološka studija močvarne vegetacije (Phragmitetea communis R. Tx. et Preising 1942) centralnog Balkana. PhD thesis. Univerzitet u Beogradu, Biološki fakultet, Beograd. Jenačković, D., Lakušić, D., Zlatković, I., Jušković, M., Ranđelović, V. 2019: Emergent wetland vegetation data recording: Does an optimal period exist? Applied Vegetation Science, 22(2): 200-212. Josifović, M. (ed.) 1970-1980: Flora SR Srbije I-X. SANU, Beograd. Jovanović, R. 1958: Tipovi močvarne vegetacije u Jasenici. Zbornik radova Biološkog instituta N. R. Srbije, 2(1): 1-36. Jovanović, R. 1965: Tipologija, ekologija i dinamika močvarne i livadske vegetacije u dolini Velike Morave. PhD thesis. Beograd. Йорданов, Д. (еd.) 1963-1986: Флора на НР България, I-VIII. София: Издателство на БАН. Katić, D. 1910: Vlasinska tresava i njezina prošlost. Spomenik Srpske Kraljevske Akademije, prvi razred, 50(8): 14-56. Košanin, N. 1910: Vlasina biljnogeografska studija. Glas Srpske Kraljevske Akademije, 81: 86-186. Laketić, D. 2013: Fitocenološka klasifikacija vegetacije jezerskog tipa u Srbiji. PhD thesis. Univerzitet u Beogradu, Biološki fakultet, Beograd. Landucci, F., Šumberová, K., Tichý, L., Hennekens, S., Aunina, L., Biță‐Nicolae, C., Borsukevych, L., Bobrov, A., Čarni, A., Bie, E.D., Golub, V. 2020: Classification of the European marsh vegetation (Phragmito‐Magnocaricetea) to the association level. Applied Vegetation Science, 23(2): 297-316. Lausi, D., Gerdol, R., Piccoli, F. 1982: Syntaxonomy of the Ostrya carpinifolia woods in the southern Alps (N-Italy) based on numerical methods. Studia Geobotanica, 2: 41-58. Lazarević, P., Stojanović, V., Jelić, I., Perić , R., Krsteski, B., Ajtić, R., Sekulić, N., Branković, S., Sekulić, G., Bjedov, V. 2012: Preliminarni spisak invazivnih vrsta u Republici Srbiji sa opštim merama kontrole i suzbijanja kao potpora budućim zakonskim aktima. Zaštita prirode, 62(1): 5-31. Ljevnaić-Mašić, B. 2010: Hidrofite Osnovne kanalske mreže Hidrosistema DTD na području Banata. PhD thesis. Prirodno-matematički fakultet, Univerzitet u Novom Sadu. Novi Sad. Ljevnaić-Mašić, B., Džigurski, D., Nikolić, L. 2016: Rare and endangered plant species and associations in the Moravica river (Serbia). Zbornik Matice srpske za prirodne nauke, 131: 121-132. Marković, G., Vićentijević-Marković, G., Tanasković, S. 2015: First record of water chestnut (Trapa natans L., Trapaceae, Myrtales) in central Serbia. Journal of Central European Agriculture, 16(4): 436-444. Mccune, B., Mefford, M. 2011: PC-ORD. Multivariate Analysis of Ecological Data. Version 6. MjM Software. Gleneden Beach, Oregon, United States of America. Milenović, V., Ranđelović, N. 2005: Association Sparganio-Glycerietum fluitantis Br.-Bl. in the Moravica river valley in Eastern Serbia. Proceeding of the 8th Symposium on Flora of Southeastern Serbia and Neighbouring Regions, 61-65. Mišić, V., Jovanović-Dunjić, R., Popović, M., Borisavljević, L., Antić, M., Dinić, A., Danon, J., Blaženčić, Ž. 1987: Biljne zajednice i staništa Stare planine. Beograd: Srpska akademija nauka i umetnosti - Odeljenje prirodno-matematičkih nauka, knjiga DXI, 49: 1-389 Mucina, L., Bültmann, H., Dierßen, K., Theurillat, J.P., Raus, T., Čarni, A., Šumberová, K., Willner, W., Dengler, J., García, R.G., Chytrý, M. 2016: Vegetation of Europe: hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities. Applied Vegetation Science, 19(S1): 3-264. Panjković, B. 2005: Akvatična i semiakvatična vegetacija Apatinskog i Monoštorskog rita. PhD thesis. Prirodno-matematički fakultet, Univerzitet u Novom Sadu. Novi Sad. Parabućski, S., Butorac, B. 1994: General review of the vegetation along the lower course of the Tisa river. Thaiszia - Journal of Botany, Košice, 4: 99- 106. Pavletić, Z. 1968: Flora mahovina Jugoslavije. Institut za botaniku, Sveučilište u Zagrebu, Zagreb. 431 p. Pełechaty, M. 1999: The phytosociological characteristic and habitat requirements of the Phragmitetum communis (Gams, 1927) Schmale 1939 phytocoenoses in the lakes of the Wielkopolski National Park. Hydrobiologia 408/409: 327–334. Perišić, S., Karadžić, B., Petković, B. 2003: Swamp vegetation of the Blace Lake (Southern Serbia). Third International Balkan Botanical Congress. Sarajevo. Polić, D. 2006: Florističko-fitocenološko proučavanje Labudovog okna. Biblioteka Academia. Zadužbina Andrejević, Beograd. Radulović, S., Laketić, D., Vukov, D. 2010: A riverside tale: assessment of altered habitat effects on macrophyte assemblage on the river Tamiš, Serbia. Archives of Biological Sciences, 62(4): 1163-1174. Ranđelović, N. 1978: Fitocenološko ekološke karakteristike brdskih travnjaka jugoistočne Srbije. PhD thesis. Prirodoslovno-matematički fakultet. Zagreb. Ranđelović, V. 1988: Močvarna vegetacija uz gornji tok Južne Morave. Diplomski rad. Prirodno- matematički fakultet, Odsek za biologiju., Univerzitet u Novom Sadu. Novi Sad. Ranđelović, V., Matejić, J., Zlatković, B. 2007a: Flora and vegetation of Batušinačke swamps near Niš. Proceeding of the 9th Symposium on Flora of Southeastern Serbia and Neighbouring Regions, 19- 40. Ranđelović, V., Zlatković, B., Matejić, J. 2007b: Swamp vegetation of order Phragmitetalia in southeastern Serbia. Proceeding of the 9th Symposium on Flora of Southeastern Serbia and Neighbouring Regions, 9-18. Ranđelović, V., Zlatković, B. 2010: Flora i vegetacija Vlasinske visoravni. Prirodno- matematički fakultet, Univerzitet u Nišu. Niš. Sarić, M. (ed.) 1986: Flora SR Srbije, X. Beograd: SANU. Sarić, M. (ed.) 1992: Flora SR Srbije, I (2nd edition) Beograd: SANU. Schneider, S., Melzer, A. 2003: The Trophic Index of Macrophytes (TIM)—A New Tool for Indicating the Trophic State of Running Waters. International Review of Hydrobiology: A Journal Covering all Aspects of Limnology and Marine Biology, 88(1): 49-67. Slavnić, Ž. 1956: Vodena i barska vegetacija Vojvodine. Zbornik Matice srpske za prirodne nauke, 10: 5-72. Stanković, Ž., Borišev, M., Simić, S., Vučković, M., Igić, R., Vidović, M., Miljanović, B. 2009: Macrophytes of the Grlište reservoir (Serbia): Fifteen years after its establishment. Archives of Biological Sciences, 61(2): 267-278. Stevanović, B., Janković, M. 2001: Ekologija biljaka sa osnovama fiziološke ekologije biljaka. NNK International, Beograd. 514 p. Stojanović, S., Butorac, B., Vučković, M. 1987: Pregled barske i močvarne vegetacije Vojvodine. Glasnik Instituta za botaniku i botaničke bašte Univerziteta u Beogradu, 21: 41-47. Stojanović, S., Lazić, D., Knežević, A., Nikolić, L., Škorić, M., Kilibarda, P., Mišković, M., Bugarski, R. 2007: Flora i vegetacija osnovne kanalske mreže HS DTD u Bačkoj. Novi Sad: Univerzitet u Novom Sadu, Poljoprivredni fakultet i JVP “Vode Vojvodine”. Šumberová K. 2011: Typhetum latifoliae Nowiński 1930. In: Chytrý M. (Ed.), Vegetace České republiky. 3. Vodní a mokřadní vegetace: 401–405, Academia, Praha. Surina, B. 2005: Subalpinska in alpinska vegetacija Krnskega pogorja v Julijskih Alpah. Scopolia, 57: 1–222. Svitok, M., Hrivnák, R., Oťaheľová, H., Dúbravková, D., Paľove-Balang, P., Slobodník, V. 2011: The Importance of Local and Regional Factors on the Vegetation of Created Wetlands in Central Europe. Wetlands, 31: 663–674. Tichý, L. 2002: JUICE, software for vegetation classification. Journal of Vegetation Science,13(3): 451-453. Tichý, L., Chytrý, M. 2006: Statistical determination of diagnostic species for site groups of unequal size. Journal of Vegetation Science, 17(6): 809-818. Topuzović, M., Pavlović, D., Ostojić, A. 2009: Temporal and spatial distribution of macrophytes in the Gruža Reservoir. Archives of Biological Sciences, 61(2): 289-296. Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M., Webb, D. A. (Eds.), 1964-1980: Flora Europaea, I-V. Cambridge University Press, London. Tzonev, R. 2009: Syntaxonomy of the natural and semi-natural vegetation of the middle Danube plain in Bulgaria. Biotechnology & Biotechnological Equipment, 23(S1): 354-359. Велчeв, В. (еd.) 1989: Флора на НР България, IХ. София: Издателство на БАН. Veljović, V. 1967: Vegetacija okolne Kragujevca. Glasnik Prirodnjačkog muzeja u Beogradu, 22 (B): 1-180. Vukićević, E., Cincović, T., Kojić, M. 1966: Pregled šumskih i močvarnih fitocenoza Mačve. Glasnik prirodnjačkog muzeja, 21 (B): 23-36. Vukov, D., Anačkov, G., Igić, R. 2003: Rare and protected plants in Zasavica river (Vojvodina, Serbia). VIIth International Symposium Interdisciplinary Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 70 Regional Research–ISIRR, 43-50. Vukov, D., Boža, P., Igić, R., Anačkov, G. 2008: The distribution and the abundance of hydrophytes along the Danube River in Serbia. Central European Journal of Biology, 3(2): 177-187. Vukov, D., Igić, R., Rućando, M., Radulović, S. 2012: Diversity of vascular hydrophytes in the Zasavica River (Serbia) – changes after thirteen years. Archives of Biological Sciences, 64(4): 1607- 1617. Vukov, D., Ilić, M., Ćuk, M., Igić, R., Janauer, G. 2017: The relationship between habitat factors and aquatic macrophyte assemblages in the Danube River in Serbia. Archives of Biological Sciences, 69(3): 427-437. Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 71 N um be r of re le vé s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Ic D % S % L oc al it y K oč an e Pu ko va c B oj ni k R ec or di ng da te 08 S ep 12 S ep 16 S ep 25 S ep t E le va ti on (m ) 19 5 20 0 25 1 L at it ud e 43.1136 43.1141 43.1143 43.1149 43.115 43.1152 43.1131 43.113 43.1126 43.1126 43.1894 43.189 43.1885 43.1884 43.1879 43.1877 43.1871 43.1862 43.1855 43.1842 43.1668 43.1673 43.1681 43.1673 43.1662 43.1657 43.1653 43.1639 43.1629 43.1621 43.1611 43.0129 L on gi tu de 21.5029 21.5028 21.503 21.5034 21.5035 21.5035 21.503 21.5031 21.5034 21.5034 21.8434 21.8437 21.8435 21.8437 21.8436 21.844 21.8444 21.8447 21.845 21.8461 21.8559 21.8556 21.8555 21.8554 21.857 21.858 21.8587 21.8618 21.8618 21.8618 21.8627 21.7245 Ty ph a la tif ol ia 5 5 5 5 5 5 5 5 5 5 5 5 4 5 5 5 5 5 5 5 5 5 5 5 5 5 4 5 5 5 5 5 99 .3 52 10 0 Ly th ru m sa lic ar ia + + + + + + + + + . . + + + . 1 . . . r . r r . r r r . r . . . 11 .8 6. 2 62 .5 Sa lix a lb a + . r + + . + + + + . . . . + . + . + + . + . 1 . 1 . . . + . . 11 .5 6 50 B id en s tr ip ar tit us . 1 . r + . . + + + . r + . . . . . r . . r . r . r . . r . r + 8 4. 2 46 .9 Sa lix e ux in a . . . + . . . . . . . . . . . . + . . . . . + 1 + + 1 + . . + + 7. 6 4 31 .2 P ol yg on um la pa th ifo liu m . 1 . . + + . . . . + r + . . . . . . . . r . . . . . . r . r . 5. 2 2. 7 28 .1 X an th iu m st ru m ar iu m . . . . + . . . . + 1 . r . + . . . r . . r . r . . . . . . + . 5. 2 2. 7 28 .1 P ol yg on um m ite . + . . + + . . . . . . + . . . . . . . . . . . . . . . r r r . 3. 8 2 21 .9 Sp ar ga ni um er ec tu m . . . + + + . . 1 + . . . . . . . . . . . . . . . . . . . . . . 3. 8 2 15 .6 U rt ic a di oi ca . . . . . + . r . . . . r . . . . . . . . r . . . . r r r . . + 3. 5 1. 8 25 C al ys te gi a se pi um . + . . . r . . . + . . + . . . . . . . . r . . . . r . . . . . 3. 1 1. 6 18 .9 M en th a aq ua tic a . . r r . + . + . + . . . . . . . . . . . . . . . . . . . . . . 2. 8 1. 5 15 .6 P op ul us s p. . . . . . . + r . + . . . . r . + . . . . . . . . . . . . . . . 2. 8 1. 5 15 .6 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation A pp en di x 1. P hy to co en ol og ic al t ab le o f Ty ph et um l at ifo lia e N ow iń sk i 1 93 0. I c - co ve ra ge in de x ac co rd in g to L au si e t al . (1 98 2) ; D % - s ha re in t ot al co ve ra ge a cc or di ng to S ur in a (2 00 5) ; S % - sp ec ie s pe rc en ta ge fr eq ue nc y w ith in th e cl us te r A pp en di ce s 72 73 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation N um be r of re le vé s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Ic D % S % Le er si a or yz oi de s . + . . + . . . . + . . . . . . . . . . . . . . . . . . . r . . 2. 4 1. 3 12 .5 So la nu m du lc am ar a . + . . . + . . . + . . . . . . . . . . . . . . . . r . . . . . 2. 4 1. 3 12 .5 P ot am og et on no do su s + . . . . . . . . . . r . . . . . . . . . . . . r r . r . . . . 2. 1 1. 1 15 .6 E pi lo bi um hi rs ut um . . + . + r . . . . . . . . . . . . . . . . . . . r . . . . . . 2. 1 1. 1 12 .5 A m or ph a fr ut ic os a . . . . . . + + . . . . . . . . . . . r . . . . . . . . . . . . 1. 7 0. 9 9. 4 H um ul us lu pu lu s . . . . . r . . . . . . . . . . . . . . . . . . . . + . . . r . 1. 4 0. 7 9. 4 P ha la ri s ar un di na ce a + . . . . . . . . . . . . . . + . . . . . . . . . . . . . . . . 1. 4 0. 7 6. 3 Ly co pu s eu ro pa eu s . . r r . . . . . . . . . . . . . . . . . . . . . r . . . . . . 1 0. 5 9. 4 St ac hy s pa lu st ri s . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0. 5 3. 1 R ob in ia ps eu do ac ac ia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . r + . 1 0. 5 6. 3 R um ex co ng lo m er at us + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 7 0. 4 3. 1 Ly si m ac hi a vu lg ar is . . . . + . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 7 0. 4 3. 1 Ta na ce tu m vu lg ar e . . . . . . . . . . . . + . . . . . . . . . . . . . . . . . . . 0. 7 0. 4 3. 1 M yr io ph yl lu m sp ic at um . . . . . . . . . . . . . . . . . . . . r . . . r . . . . . . . 0. 7 0. 4 6. 3 R ub us c ae si us . . . . . . . . . . . . . . . . . . . . . . . . . . r r . . . . 0. 7 0. 4 6. 3 G al iu m ap ar in e . . . . . r . . . . . . . . . . . . . . . . . . . . r . . . . . 0. 7 0. 4 6. 3 A lth ae a offi ci na lis . . . . . . . . . . . . r . . . . . . . . . . . . . . . . . . . 0. 3 0. 2 3. 1 P ot am og et on cr is pu s . . . . . . . . . . . . . . . . . . . . . r . . . . . . . . . . 0. 3 0. 2 3. 1 E ch in oc hl oa cr us -g al li . . . . . . . . . . . . . . . . . . . . . . . . . . . . r . . . 0. 3 0. 2 3. 1 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation N um be r of re le vé s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Ic D % S % Le m na m in or . . . . . . . . . . . . . . . . . . . . . . . . . . . . r . . . 0. 3 0. 2 3. 1 E ch in oc ys tis lo ba ta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . r . 0. 3 0. 2 3. 1 74 75 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Appendix 2. Phytocoenological table of Phalaridetum arundinaceae Libbert 1931. Ic - coverage index according to Lausi et al. (1982); D% - share in total coverage according to Surina (2005); S% - species percentage frequency within the cluster Number of relevés 1 2 3 4 5 6 7 8 Ic D% S% Locality Kočane Kosančić Recording date 8 Sep 12 Sep 25 Sep Elevation (m) 194 194 194 195 195 195 195 222 Latitude 43 .1 14 3 43 .1 15 3 43 .1 13 43 .1 12 4 43 .1 89 3 43 .1 88 5 43 .1 87 4 43 .0 78 8 Longitude 21 .5 03 21 .5 03 5 21 .5 03 1 21 .5 03 5 21 .8 43 5 21 .8 43 7 21 .8 44 3 21 .7 86 4 Phalaris arundinacea 5 5 5 5 5 5 4 5 99 41 100 Mentha aquatica r + + 1 + . 2 . 21 8.6 75 Lythrum salicaria r + + + + . + . 15 6.3 75 Sparganium erectum + + + + . 1 . . 15 6.3 63 Salix alba + + + + . . . + 14 5.7 63 Xanthium strumarium . . + + + . + . 11 4.6 50 Populus sp. + r . . 1 . . . 8.3 3.4 38 Leersia oryzoides + . + + . . . . 8.3 3.4 38 Typha latifolia + . . . + . + . 8.3 3.4 38 Urtica dioica r . + . r . . . 8.3 3.4 38 Epilobium hirsutum r . . . + . . . 4.2 1.7 25 Polygonum mite + . . . r . . . 4.2 1.7 25 Calystegia sepium . . + . . r . . 4.2 1.7 25 Tanacetum vulgare . . 1 . . . . . 4.2 1.7 13 Bidens tripartitus . . . . . . r + 4.2 1.7 25 Salix euxina + . . . . . . . 2.8 1.1 13 Amorpha fruticosa . + . . . . . . 2.8 1.1 13 Lycopus europaeus . . . . + . . . 2.8 1.1 13 Polygonum lapathifolium . . . . + . . . 2.8 1.1 13 Myriophyllum spicatum . . . . . . . + 2.8 1.1 13 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Appendix 3. Phytocoenological table of Polygono-Bidentetum tripartitae (W. Koch 1926) Lohm. 1950. Ic - coverage index according to Lausi et al. (1982); D% - share in total coverage according to Surina (2005); S% - species percentage frequency within the cluster Number of relevés 1 2 3 Ic D% S% Locality Kočane Recording date 08 Sep Elevation (m) 195 Latitude 43 .1 14 1 43 .1 14 3 43 .1 12 9 Longitude 21 .5 02 8 21 .5 03 21 .5 03 1 Polygonum lapathifolium 4 5 4 93 23 100 Bidens tripartitus 1 1 4 52 13 100 Polygonum mite 2 + + 33 8.4 100 Lythrum salicaria 1 + . 19 4.7 67 Xanthium strumarium + 1 . 19 4.7 67 Leersia oryzoides . 2 . 19 4.7 33 Sparganium erectum + + . 15 3.7 67 Calystegia sepium + + 15 3.7 67 Echinochloa crus-galli r + . 11 2.8 67 Erigeron canadensis . r + 11 2.8 67 Tanacetum vulgare . r + 11 2.8 67 Lysimachia vulgaris 1 . . 11 2.8 33 Mentha aquatica + . . 7.4 1.9 33 Lycopus europaeus + . . 7.4 1.9 33 Aristolochia clematitis + . . 7.4 1.9 33 Urtica dioica + . . 7.4 1.9 33 Phalaris arundinacea + . . 7.4 1.9 33 Solanum dulcamara + . . 7.4 1.9 33 Rubus caesius + . . 7.4 1.9 33 Amorpha fruticosa . + . 7.4 1.9 33 Salix euxina . + . 7.4 1.9 33 Chenopodium album . + . 7.4 1.9 33 Robinia pseudoacacia . . + 7.4 1.9 33 Rumex conglomeratus . . + 7.4 1.9 33 76 77 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation A pp en di x 4. P hy to co en ol og ic al ta bl e of G ly ce rio -S pa rg an ie tu m n eg le ct i K oc h 19 26 . I c - co ve ra ge in de x ac co rd in g to L au si e t a l. (1 98 2) ; D % - s ha re in to ta l c ov er ag e ac co rd in g to S ur in a (2 00 5) ; S % - sp ec ie s pe rc en ta ge fr eq ue nc y w ith in th e cl us te r N um be r of re le vé s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Ic D % S % L oc al it y K oč an e Pu ko va c Donje Brijanje Bojnik R ec or di ng da te 08 S ep 12 S ep 16 S ep 25 S ep E le va ti on (m ) 19 5 19 6 20 0 21 8 25 1 L at it ud e 43.11356 43.11404 43.11429 43.11311 43.11255 43.11239 43.11222 43.18922 43.18825 43.18822 43.18779 43.18643 43.18616 43.18478 43.16677 43.16702 43.16714 43.16611 43.16495 43.16474 43.16388 43.16378 43.16343 43.16296 43.16218 43.16152 43.16073 43.16055 43.09847 43.0984 43.01257 L on gi tu de 21.50288 21.50282 21.50307 21.50306 21.50336 21.5034 21.50352 21.84363 21.84367 21.84347 21.84394 21.84498 21.84496 21.84558 21.85568 21.85548 21.85567 21.85677 21.86029 21.86074 21.86166 21.86159 21.86172 21.86183 21.86182 21.8619 21.8626 21.86237 21.81782 21.81832 21.72439 Sp ar ga ni um er ec tu m 5 5 5 5 5 5 5 5 5 5 5 5 4 5 3 5 5 5 5 5 5 5 5 5 5 5 5 5 5 4 5 98 .6 48 .8 10 0 Ly th ru m sa lic ar ia 1 1 + + + + + + . 1 + r + + 2 + r + . r . + r + r r . r . . . 16 .8 8. 3 77 .4 P ol yg on um m ite . + + 1 . . . . . . . . . + . . + . r . . . + . . r . . + 4 + 9. 7 4. 8 35 .5 B id en s tr ip ar tit us . + r . + + . . . . . . . + . . + . + r r . + r r . . . + + + 9 4. 4 48 .4 P ol yg on um la pa th ifo liu m . 1 + + . . + . . . . . . + . . 1 . r r . . + . . . . . + . 1 8. 2 4. 1 35 .5 M en th a aq ua tic a . + . + 1 . . . + + . + + . r r . r . . r . . . . r . . . . . 7. 2 3. 6 38 .7 Sa lix a lb a . . + r + . + . . . + . 1 . . . . . . . . . . . . . . + + . . 5. 7 2. 8 25 .8 P ot am og et on no do su s . . . . . + r + . . . + r . . . . r r r r . . . r . r r . . . 5. 4 2. 7 38 .7 Sa lix e ux in a . r . . . . . . . . . . 1 . . + . . . . r . . . . + . . + + . 4. 7 2. 3 22 .6 X an th iu m st ru m ar iu m . . . . . r . . + . . . . + . . r . r . . . . r . r . . . r + 4. 3 2. 1 29 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation N um be r of re le vé s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Ic D % S % Ly co pu s eu ro pa eu s . + . . . . . . . . . . . . r . . r r . . . . . . r . r . r . 2. 9 1. 4 22 .6 P ha la ri s ar un di na ce a 1 . . . . . . . . + . . + . . . . . . . . . . . . . . . . . . 2. 5 1. 2 9. 7 Ty ph a la tif ol ia + . . + . . . . . . . . . . 1 . . . . . . . . . . . . . . . . 2. 5 1. 2 9. 7 U rt ic a di oi ca . . . r . . . r . . . . r . r . . r . . . . . . . r . . . . r 2. 5 1. 2 22 .6 M yr io ph yl lu m sp ic at um . . . . . . . . . . . . . . . . . r . r r . . r r . r r . . . 2. 5 1. 2 22 .6 Ta na ce tu m vu lg ar e . . . . . + . . . . . . . . . . . r . . . . r . . r . r . . . 2. 2 1. 1 16 .1 C al ys te gi a se pi um . . . . . . . . . . . r . . r . . r . . . . . . . r . . . r r 2. 2 1. 1 19 .4 R ob in ia ps eu do ac ac ia . . . . . . . . . + . . . . . . . . . r . . . . . . . + . . . 1. 8 0. 9 9. 7 So la nu m du lc am ar a . r . . . . . . . . . . . . + r . . . . . . . . . . . . . . . 1. 4 0. 7 9. 7 A m or ph a fr ut ic os a . . + . + . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 4 0. 7 6. 5 Le er si a or yz oi de s . . . + . . . . . . . . . . . . . r . r . . . . . . . . . . . 1. 4 0. 7 9. 7 G al iu m ap ar in e . . . . . . . r . . . . . . . . . r . . . . r . . r . . . . . 1. 4 0. 7 12 .9 R ub us c ae si us . . . . . . . . . . . r . . . . . . r r . r . . . . . . . . . 1. 4 0. 7 12 .9 E pi lo bi um hi rs ut um . . . . . . . . . . . . . . . . . . . r . r . . . r . . . . . 1. 1 0. 5 9. 7 Le m na m in or . . . . . . . . . . . . . . . . . . . r . . . r . . . . . r . 1. 1 0. 5 9. 7 E ch in oc hl oa cr us -g al li . . r . . . . . . . . . . . . . . . . . . . . . . . r . . . . 0. 7 0. 4 6. 5 P ot am og et on cr is pu s . . . . . . . + . . . . . . . . . . . . . . . . . . . . . . . 0. 7 0. 4 3. 2 Sc ut el la ri a ga le ri cu la ta . . . . . . . . . . . . . . . . . r . . . . . r . . . . . . . 0. 7 0. 4 6. 5 Sc ro ph ul ar ia no do sa . . . . . . . . . . . . . . . . . r . . . . . . . . . . . . . 0. 4 0. 2 3. 2 78 79 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliationr N um be r of re le vé s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Ic D % S % B er ul a er ec ta . . . . . . . . . . . . . . . . . . . . r . . . . . . . . . . 0. 4 0. 2 3. 2 St el la ri a ne gl ec ta . . . . . . . . . . . . . . . . . . . . . . . . . r . . . . . 0. 4 0. 2 3. 2 E ch in oc ys tis lo ba ta . . . . . . . . . . . . . . . . . . . . . . . . . r . . . . . 0. 4 0. 2 3. 2 E le oc ha ri s pa lu st ri s . . . . . . . . . . . . . . . . . . . . . . . . . . r . . . . 0. 4 0. 2 3. 2 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Appendix 5. Phytocoenological table of Phragmitetum australis Savič 1926. Ic - coverage index according to Lausi et al. (1982); D% - share in total coverage according to Surina (2005); S% - species percentage frequency within the cluster Number of relevés 1 2 3 4 5 6 7 8 9 Ic D% S% Locality Kočane Pukovac Recording date 08 Sep 12 Sep 16 Sep Elevation (m) 195 200 Latitude 43 .1 12 7 43 .1 88 43 .1 85 3 43 .1 84 8 43 .1 64 5 43 .1 63 6 43 .1 63 5 43 .1 63 1 43 .1 63 Longitude 21 .5 03 3 21 .8 43 8 21 .8 45 3 21 .8 45 5 21 .8 61 2 21 .8 61 6 21 .8 61 7 21 .8 61 8 21 .8 62 1 Phragmites communis 5 5 5 5 5 5 5 5 5 100 56 100 Bidens tripartitus + . . . + r r r . 9 5 56 Urtica dioica r . r . + r r . . 7 4 56 Salix.euxina . . . . + + + . . 7 4 33 Robinia pseudoacacia . r + . . . . . + 6 4 33 Salix alba + + . . . . . . . 5 3 22 Echinocystis lobata . . . . + . . r r 5 3 33 Typha latifolia 1 . . . . . . . . 4 2 11 Lythrum salicaria + . . . . r . . . 4 2 22 Polygonum lapathifolium + . . . . . . r . 4 2 22 Sparganium erectum . . . r + . . . . 4 2 22 Humulus lupulus + . . . . . . . . 3 1 11 Mentha aquatica + . . . . . . . . 3 1 11 Polygonum mite . . . . + . . . . 3 1 11 Epilobium hirsutum . . . . + . . . . 3 1 11 Galium aparine . . . . + . . . . 3 1 11 Rubus caesius . . . . . r r . . 3 1 22 Lycopus europaeus . . . . . r r . . 3 1 22 Populus sp. . r . . . . . . . 1 1 11 Potamogeton nodosus . . . r . . . . . 1 1 11 Erigeron canadensis . . . . . r . . . 1 1 11 Tanacetum vulgare . . . . . r . . . 1 1 11 Xanthium strumarium . . . . . . r . . 1 1 11 80 81 BIOLOGICA NYSSANA ● 13 (1) September 2022: 59-81 Vukotić et al. ● Aquatic and wetland plant communities of the Pusta River (Southern Serbia): floristic characteristics and syntaxonomic affiliation Appendix 6. Phytocoenological table of Myriophyllo-Potametum Soó 1934. Ic - coverage index according to Lausi et al. (1982); D% - share in total coverage according to Surina (2005); S% - species percentage frequency within the cluster Number of relevés 1 2 3 4 5 Ic D% S% Locality Kočane Pukovac Recording date 08 Sep 16 Sep Elevation (m) 195 200 Latitude 43 .1 14 6 43 .1 64 5 43 .1 64 43 .1 62 3 43 .1 66 8 Longitude 21 .5 03 2 21 .8 61 2 21 .8 61 6 21 .8 61 7 21 .8 55 8 Myriophyllum spicatum 5 5 4 5 5 98 69 100 Potamogeton crispus 1 . . . 4 24 17 40 Potamogeton nodosus + . 2 + . 20 14 60 Appendix 7. Phytocoenological table of Potametum nodosi Soó (1928) 1960, Segal 1964. Ic - coverage index according to Lausi et al. (1982); D% - share in total coverage according to Surina (2005); S% - species percentage frequency within the cluster Number of relevés 1 2 3 4 5 6 7 8 Ic D% S% Locality Pukovac Recording date 16 Sep Elevation (m) 200 Latitude 43 .1 66 8 43 .1 66 3 43 .1 65 3 43 .1 64 9 43 .1 64 7 43 .1 61 7 43 .1 60 8 43 .1 60 6 Longitude 21 .8 55 8 21 .8 56 7 21 .8 59 1 21 .8 59 8 21 .8 60 9 21 .8 62 2 21 .8 62 6 21 .8 62 7 Potamogeton nodosus 5 5 5 4 4 5 5 5 97 63 100 Myriophyllum spicatum . 4 1 + 1 1 2 4 44 29 87.5 Sparganium erectum . . . 3 . . . . 10 6 12.5 Lemna minor . . . . + . . . 3 2 12.5