Lindernia dubia

Škondrić, Siniša, Perić, Ranko & Knežević, Jelena, 2023, Genus Lindernia All. (Linderniaceae) in Bosnia and Herzegovina, Ecologica Montenegrina 65, pp. 13-23 : 15-16

Lindernia dubia (L.) Pennell

Lindernia dubia (L.) Pennell in Acad. Nat. Sci. Philadelphia Monogr. 1: 141. 1935 ≡ Gratiola dubia L., Sp. Pl. 1: 17. 1753 ≡ Capraria gratioloides L., Syst. Nat., ed. 10, 2: 1117. 1759, nom. illeg. ≡ Lindernia pyxidaria L., Mant. Pl. 2: 252. 1771, nom. illeg. ≡ Ilysanthes gratioloides Benth. in Candolle, Prodr. 10: 419. 1846, nom. illeg. ≡ Lindernia gratioloides J. Lloyd & Foucaud, Fl. Ouest France, ed. 4: 246. 1886, nom. illeg. ≡ Limnophila dubia (L.) M. R. Almeida, Fl. Maharashtra 3 B: 393. 2001, nom. illeg. [non Limnophila dubia Bonati in Bull. Soc. Bot. France 55: 511. 1908].

= Lindernia dubia var. riparia (Raf.) Fernald in Rhodora 44: 444. 1942 ≡ Ilysanthes riparia Raf. in Ann. Nat.: 13. 1820. = Lindernia anagallidea (Michx.) Pennell in Acad. Nat. Sci. Philadelphia Monogr. 1: 152. 1935 ≡ Gratiola anagallidea Michx., Fl. Bor.- Amer. (Michaux) 1: 6. 1803.

= Lindernia dilatata Muhl. ex Elliott, Sketch Bot. S. Carolina 1: 16. 1816.

Description. Annual herb, glabrous to sparsely stipitate glandular near the stem base. Stem 1.5 ― 27(― 38) cm, erect to ascending, rooting at the lower nodes, branching from the stem base to throughout the stem. Leaves 1 ― 37 × 0.5 ― 18 mm, simple, cauline, opposite, sessile, spatulate, lanceolate, oblanceolate, elliptic, ovate, obovate, or suborbicular with acuminate, acute, obtuse or rounded apex; minutely glandular-punctate on both surfaces or sometimes sparsely stipitate glandular; leaf base rounded, attenuate or cuneate-clasping; leaf margins entire to remotely, rarely coarsely tooted or muriculate; leaf 5-veined, venation palmate to rarely appearing pinnate ( Fig. 1A ). Flowers bisexual, solitary on pedicles in the leaf axis, chasmogamous or sometimes cleistogamous; pedicels 0.5 ― 31 mm, usually shorter than subtending leaf, erect to spreading, commonly reflexed in fruit, glabrous or often stipitate glandular near base ( Fig. 1A ). Calyx 0.9 ― 6.5 mm, actinomorphic to slightly zygomorphic, 5-lobed to the base; calyx tube 0.2 ― 0.7 mm; calyx lobes lanceolate, linear or rarely elliptic, acuminate, glabrous, mucronulate, with entire margins, or sometimes glandular-punctate or sparsely stipitate glandular. Corolla zygomorphic, white, bluish or lavender, surface with lavender or purple spots and markings; base of the anterior lobes with trichome tufts; corolla tube 2.5 ― 7(― 8) mm; anterior lip ca. twice as long as posterior, apex retuse. Androecium consists of 2 fertile stamens and 2 staminodes; fertile anthers coherent with glabrous filaments 0.6 ― 1.8 mm; staminodial filament with free part 0.5 ― 2 mm, appendages 0.2 ― 1.4 mm, setose, included in or somewhat exerted from the tube. Gynoecium consists of a single pistil; style 0.6 ― 4.8 mm, usually persisting until fruit dehisces; stigma 0.2 ― 0.6 × 0.2 ― 0.6 mm, 2-parted. Capsule 1.4 ― 6.3(― 7.5) × 1.2 ― 3.3 mm, ellipsoid or oblique, sometimes globose or ovoid, glabrous, smooth or often striate, hardly shorter or often somewhat exceeding calyx, infrequently twice as long as calyx. Seeds 0.22 ― 0.51 × 0.11 ― 0.3 mm, gold or pale yellow, ellipsoid or rectangular in outline, often 6-ribbed; seed coat areolate, sparsely to densely minutely tuberculate, minute cuticular rigdes are often present while other cuticular projections are present or absent.

General distribution and habitat. L. dubia is distributed in North America ( Canada, U.S.A., Cuba, Dominican Republic, Puerto Rico, Mexico, Belize, Guatemala, Honduras, Nicaragua, Panama) and South America ( Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Venezuela). The species was introduced in Europe and East Asia ( Fischer et al. 2013). In Europe, L. dubia was first recorded in the 19th century in France ( Llyod 1868). At present the occurrence of this species has been recorded in Albania ( Barina et al. 2015), Austria ( Raabe 2019, 2021), Belgium ( Vannerom 1994), Bulgaria (Markova 1995), Croatia ( Csiky & Purger 2008), Czech Republic ( Kurka 1990; Šumberová et al. 2012), Germany ( Jage 1964), Greece ( Dimopoulos et al. 2013), Hungary ( Molnár et al. 2000; Schmotzer 2015), Italy ( Pignatti 1982; Galasso et al. 2018), Netherlands ( Simons & Jansen 2018), North Macedonia ( Matevski 2017), Poland ( Drobnik & Buchalik 2004), Portugal ( Vasconcelos et al. 1999), Romania ( Ciocârlan & Costea 1994), Serbia ( Ranđelović et al. 2006; Perić & Knežević 2019), Slovakia ( Schmotzer 2015; Hrivnák et al. 2016; Dítě & Dítě 2019), Slovenia ( Seliškar et al. 1995; Trpin et al. 1995), Spain ( Sanz-Elorza et al. 2001), Switzerland ( Lauber et al. 2012) and Turkey ( Özhatay & Kültür 2006). In its native as well as secondary distribution range, L. dubia occurs in a variety of wet habitats, such as periodically flooded habitats, muddy or sandy banks of rivers, lakes, ponds and rice-fields ( Šumberová et al. 2012; Hrivnák et al. 2016; Perić & Knežević 2019).

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; Ramsar site “Bardača Wetland”, Gaj, Sava River , near the confluence of Matura River into the Sava River , muddy drawdown zone of the riverbank, 45.12650°N, 17.45037°E, altitude 90 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; Kozarska Dubica, Demirovac, Općine, Sava River, sandy drawdown zone of the riverbank, 45.22670°N, 16.93853°E, altitude 90 m a.s.l., 24 August 2022, leg. S. Škondrić, det. S. Škondrić, R. Perić, J. Knežević .

Prospective introduction pathways. Watercourses, especially those with shipping activities, represent an important corridor for the spread of alien species ( Jehlík et al. 2005). As one of the river corridor plants ( Burkart 2001), probable dispersal vectors of L. dubia are stream water, waterfowl and rubber boots ( Šumberová et al. 2012). Also, Šumberová et al. (2012) found seed dispersal of L. dubia via vehicles used in fish farming. Since all localities where L. dubia is present are located along the Sava River ( Fig. 2 ), it is highly probable that the seeds were transported by the stream water. Also, Ramsar site “Bardača Wetland” is characterized by a significant diversity of ornithofauna as well as being one of a series of migration points for migratory birds ( Obratil 1972 ― 73), and a possible dispersal vector could be aviochory.

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).