Lindernia procumbens (Krock.) Philcox

Škondrić, Siniša, Perić, Ranko & Knežević, Jelena, 2023, Genus Lindernia All. (Linderniaceae) in Bosnia and Herzegovina, Ecologica Montenegrina 65, pp. 13-23 : 16-19

Lindernia procumbens (Krock.) Philcox

Specimens examined. Bosnia and Herzegovina, Republic of Srpska , Ramsar site “Bardača Wetland”, Bajinci , Sava River , sandy drawdown zone of the riverbank, 45.11018°N, 17.48066°E, altitude 86 m a.s.l., 22 July 2022, leg. S. Škondrić, det. S. Škondrić, R. Perić, J. Knežević; Ramsar site “Bardača Wetland”, Bajinci, Sava River, sandy drawdown zone of the riverbank, 45.10992°N, 17.48094°E, altitude 86 m a.s.l., 9 August 2022, leg. S. Škondrić, det. S. Škondrić, R. Perić, J. Knežević; Kozarska Dubica, Međeđa, Mlinarice, Sava River, sandy drawdown zone of the riverbank, 45.22701°N, 16.96892°E, altitude 89 m a.s.l., 24 August 2022, leg. S. Škondrić, det. S. Škondrić, R. Perić, J. Knežević .

Known distribution in Bosnia and Herzegovina. Velika Tišina, sub: Lindernia pyxidaria L. ( Bjelčić 1954: 187); Šamac [Bosanski Šamac], Velika Tišina, sub: Lindernia gratioloides (L.) Poir. ( Bjelčić 1967: 66); Gradiška [Bosanska Gradiška], sub: Lindernia gratioloides (L.) Poir. ( Bjelčić 1967: 66).

Habitat of Lindernia species in Bosnia and Herzegovina. According to newly available data, L. dubia is present only in the area of the Ramsar site “Bardača Wetland” and Kozarska Dubica municipality in Bosnia and Herzegovina ( Fig. 2 ). The species was found at four localities on the sandy drawdown zone of the Sava River in the vegetation of the alliance Nanocyperion Koch 1926 belonging to the class Isoëto-Nanojuncetea. The vegetation is characterized by pioneer ephemeral dwarf-cyperaceous vegetation in periodically freshwater flooded habitats in Eurasia.

In the area of the Ramsar site “Bardača Wetland”, two localities where L. dubia grew were found. The first locality is situated in Bajinci village ( Fig. 1D ). In late summer and early autumn of 2022, the Sava River receded at least 50 m from the shore and left a gently sloping sandy bank open. In this locality, in addition to the much more abundant L. dubia , L. procumbens was also present. The area of this habitat was cca. 500 m 2, and L. dubia was present with cca. 100 individuals, while L. procumbens was present with cca. 30 individuals. Both species of the genus Lindernia were accompanied by the following species: Abutilon theophrasti Medik. , Chenopodium album L., Cyperus michelianus (L.) Link, Echinocystis lobata (Michx.) Torr. & A. Gray , Portulaca oleracea L. and Sagittaria sagittifolia L. The second finding of L. dubia in the area of Ramsar site “Bardača Wetland” is located in Gaj village, on the banks of the Sava River, next to the confluence of the Matura River into the Sava River ( Fig. 1E ). Here, the Sava riverbank is almost at a right angle. During the late summer and early autumn of 2022, the Sava River receded about 10 m from the steep bank, leaving an exposed muddy bank and a narrow band (cca. 50 m 2) of Nanocyperion vegetation was formed. Three individuals of L. dubia were found in this locality, which were accompanied by Rorippa palustris (L.) Besser and Cyperus michelianus (L.) Link. The species L. procumbens was absent in this locality.

In the area of the municipality of Kozarska Dubica, L. dubia was found in two localities in the villages Međeđa ( Fig. 1F ) and Demirovac ( Fig. 1G ). In Međeđa (Mlinarice), the river Sava forms steep banks. During the late summer and early spring of 2022, the water receded at least 50 m, exposing a slightly sloping sandy shore. Nanocyperion vegetation is well formed here, covering an area of cca. 3000 m 2, where, most abundant L. dubia (cca. 1000 individuals) was associated with the less abundant L. procumbens (cca. 100 individuals) ( Fig. 1C ). In addition to the mentioned species, there were also Abutilon theophrasti Medik. , Chenopodium album L., Cyperus fuscus L., Cyperus glomeratus L., Cyperus michelianus (L.) Link, Echinochloa crus-galli (L.) P. Beauv., Lythrum salicaria L., Persicaria lapathifolia (L.) Delarbre, Portulaca oleracea L. and Rorippa sylvestris (L.) Besser. Another locality in the municipality of Kozarska Dubica is located along the river Sava in the village of Demirovac (Općine). The locality is situated near the embankment and pumping station in the village of Glavinac. In this locality, the water has also receded quite a bit, exposing a wide sandy riverbank. From the top of the bank, where there are several springs, the water drains towards the Sava riverbed. In this locality, the Nanocyperion vegetation covers an area of about 400 m 2. Five L. dubia individuals were found here, which were accompanied by Chenopodium album L., Cyperus fuscus L., Cyperus glomeratus L., Cyperus michelianus (L.) Link, Echinochloa crus-galli (L.) P. Beauv. and Lythrum salicaria L. The rare and threatened L. procumbens was absent in this locality.

The nearest sites of L. dubia are situated in central Croatia, Slavonia (settlements Novi Grad, Jaruge, Sikirevci and Slavonski Šamac along the Sava River) and Moslavina Region (Garešnica River) in Nanocyperion vegetation ( Rimac et al. 2020, 2021). Similar to our localities in the villages Bajinci and Međeđa, L. dubia grows together with L. procumbens on the sandy banks of the Garešnica River ( Rimac et al. 2021).

L. dubia and L. procumbens have the ability to form soil seed banks ( Šumberová et al. 2012). Soil seed banks represent a significant feature of species that inhabit ephemeral habitats like river banks ( Poschlod et al. 2013). According to Šumberová et al. (2012), L. procumbens has shown the capacity to remain in the soil seed bank for at least 7-9 years without appearing in recent vegetation.

In accordance with our research and literature data ( Täuber & Petersen 2000; Deil 2005; Popiela 2005; Csiky & Purger 2008; Király et al. 2008; Šumberová & Hrivnák 2013; Dítětová et al. 2016; Melečková et al. 2016; Perić & Knežević 2019; Navrátilová & Navrátil 2022), the following can be concluded: 1) Nanocyperion vegetation is one of the most threatened wet habitat types in Europe, primarily due to river regulation, pollution and invasive species; 2) Nanocyperion is a pioneer type of vegetation that survives only where there is regular disturbance of the habitat, either in the form of erosion and flooding during the arrival and retreat of water, or during grazing and trampling by game and domestic livestock, which prevents overgrowth by other types of vegetation and maintains the pioneer character of the habitat; 3) today, such habitats are created secondary to sustainable animal husbandry in wet areas, which means that the preservation of traditional practices in animal husbandry is of primary importance in their protection, which emphasizes the primordial connection of folk tradition and culture of the local community for the preservation of this type of habitat; 4) due to all of the above, many species from this type of vegetation are threatened regionally or more widely and are listed in red lists, books, conventions; 5) due to its pioneering nature, the short life cycle of only a few weeks and the inaccessibility of habitats in floodplains, this type of vegetation is one of the least studied, especially in our region.

Lindernia species are common weeds in rice fields in Japan. It was found that the species L. procumbens , L. dubia and L. micrantha are resistant to sulfonylurea herbicides ( Uchino et al. 1999; Olofsdotter et al. 2000; Shibayama 2001; Young Son & Rutto 2002; Uchino & Watanabe 2002; Yoshino et al. 2006). Thus, in relation to other Nanocyperion species, Lindernia species have a comparative advantage that enables them to secondary expand their range in anthropogenic wetlands ( Kovačić 2005). The above applies especially to L. dubia , which has success as a naturalized alien species in amphibian habitats. L. dubia was found in four localities during our field research, and L. procumbens shares habitat with L. dubia in only two of them. It can be assumed that L. dubia suppresses L. procumbens due to its more robust habit and ability to colonize different types of wetland vegetation. L. dubia possesses less temperature and moisture demands, and it manages to germinate and reproduce over a longer period of time compared to L. procumbens ( Šumberová et al. 2012; Hrivnák et al. 2016; Kaplan et al. 2016). According to Perić & Knežević (2019), L. dubia is more typical to anthropogenically disturbed habitats and L. procumbens to more preserved ones.

Alien status of L. dubia in Bosnia and Herzegovina. Based on our results, the alien status of L. dubia can be assessed as initial phase of naturalisation in Bosnia and Herzegovina.

Threatened status of L. procumbens in Bosnia and Herzegovina. The current status of the species L. procumbens in Bosnia and Herzegovina is assessed as Endangered – EN B1ab(iii)+B2ab(iii).

Figures

Figure 1. Species of the genus Lindernia and their habitat in Bosnia and Herzegovina: A ― L. dubia; B ― L. procumbens; C ― L. procumbens (left) and L. dubia (right); D ― Bajinci; E ― Gaj; F – Međeđa; G – Demirovac (Photos by S. Škondrić).

Figure 2. Distribution of Lindernia dubia and L. procumbens in Bosnia and Herzegovina (Blue arrow represents the exact position of Velika Tišina).