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Noves contribucions a les espècies aŀlòctones de Ludwigia (Onagraceae) a Catalunya Butlletí de la Institució Catalana d’Història Natural
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Butlletí ICHN 83, 2019
New contributions to allochthonous Ludwigia species (Onagraceae) on Catalonia
Noves contribucions a les espècies aŀlòctones de Ludwigia (Onagraceae) a Catalunya
Jordi Bou Manobens*, Luis Portillo ** & Antoni Curcó i Masip***
* LAGP-Flora i Vegetació. Institut de Medi Ambient. Universitat de Girona. Campus Montilivi. 17003 Girona.
** UMR985 Écologie et Santé des Écosystèmes. Agrocampus Ouest. INRA. 35042 Rennes France Cedex.
*** Parc Natural del Delta de l’Ebre. Generalitat de Catalunya. Av. Generalitat, 46. 43870 Deltebre.
Autor per a la correspondència: Jordi Bou: A/e:
Rebut: 28.02.2019. Acceptat: 18.03.2019. Publicat: 31.03.2019
Butlletí de la Institució Catalana d’Història Natural, 83: 45-48. 2019 ISSN 2013-3987 (online edition): ISSN: 1133-6889 (print edition)
DOI: 10.2436/20.1502.01.4
Ludwigia grandiora (Michaux) Greuter & Burdet subsp.
hexapetala (Hook. & Arn.) Nesom & Kartesz
Mo n t s i à : Amposta, al riu Ebre, CF0109, 0 m, 22-VII-
2018, J. Bou (HGI 23947).
Allochthonous species from the genus Ludwigia on the
Iberian Peninsula have often generated taxonomic confusion,
since although the various plant catalogues mention only
Ludwigia grandiora in this region (Nieto Feliner, 2000;
Bolòs et al., 1993), Verloove & Sánchez (2008) reported L.
peploides from the Llobregat River. In addition, in 2016, one
of us (J.B.) published a study on the allochthonous taxa of
Ludwigia in Catalonia, in which it was concluded that all the
samples analysed corresponded to L. peploides subsp. mon-
tevidensis (Bou Manobens & Font Garcia, 2016), a hydro-
phyte from the Americas that has invaded both rivers and still
waters throughout a large part of Europe (CABI, 2019).
In order to increase our knowledge of the dynamics and
situation of L. peploides in Catalonia, in 2018 a campaign
was launched to collect samples from the populations of sev-
eral Catalan basins. In the Ebre River, there was a popula-
tion (Fig. 1a), not recognised in our previous study, found
in the main course of the river, in an area bordering the Ebre
Delta Natural Park. An analysis of the morphology of vari-
ous specimens determined that it was Ludwigia grandiora
subsp. hexapetala (HGI 23947). This taxon naturalised in the
Lez River in Montpellier (France) in 1826 (Dandelot, 2004),
from where it has expanded its range substantially, becoming
one of the invasive aquatic plants with the greatest impact
(Ruaux et al., 2009), with similar biology and dynamics to
L. peploides subsp. montevidensis. The presence of L. gran-
diora subsp. hexapetala in Catalonia, and specically in
the area of the Ebre Delta, which is geographically more re-
mote from the populations found in France than other basins,
raises several doubts about its introduction in Catalonia, the
transport vector, and the population it originated from, as it
could have come from either European populations or have
originated from a native American population.
Figure 1. Herbaceous Ludwigia spp. plants in summer 2018: a) L. grandiora subsp. hexapetala, in the Ebre River, at Amposta; and b) L. peploides
subsp. montevidensis, in the Ter River, near Colomers.
a b
Butlletí ICHN 83, 2019
Ludwigia peploides (Kunth) P.H. Raven subsp. monteviden-
sis (Spreng.) P.H. Raven
Ba i x EM p o r d à : Torroella de Montgrí, al Ter, entre la resclosa
i el pont, EG0954, 4 m, 15-VII-2016, J. Bou (HGI 23251).
al t EM p o r d à : Palau-Saverdera, a la Bassa del Camí Ral,
EG1181, 7 m, 23-VII-2018, J. Bou (HGI 23944); Palau-Sav-
erdera, basses de les Garrigues, EG1181, 10 m, 23-VII-2018,
J. Bou (HGI 23945). Ba i x ll o B r E g a t : El Prat de Llobregat,
riba esquerra del Llobregat, DF2377, 3 m, 22-VII-2018, J.
Bou (HGI 23946). Ba i x EB r E : Deltebre, Secanella, bassa de
la Barraca d’en Salvador, CF0911, 0 m, 22-VII-2018, J. Bou
(HGI 23948).
According to Bou Manobens & Font Garcia (2016) L.
peploides subsp. montevidensis is naturalised and expanding
its range in Catalan rivers, which is very worrying due to the
high risk of invasion of river ecosystems (Rodríguez-Merino
et al., 2017). This taxon is known to have an enormous ca-
pacity for vegetative multiplication through small propagules
(Ruaux et al., 2009), something that has been demonstrated
by how easily it recovered after several attempts to mechani-
cally control its presence in two specic populations. In Alt
Empordà, in an endeavour to recover a pond in poor ecologi-
cal condition, the mechanical eradication of the population
was attempted (ACN, 2016), but new populations have ap-
peared (HGI 23944 and HGI 23945), probably due to prop-
agules or viable seeds that were not removed. The second
case involved a pond in Baix Ebre, linked to a house, where
heavy machinery was used to eliminate the population and
prevent its propagation. However, in this case, even though
part of the soil where it had rooted was removed (personal
observation), this was not sufcient and the population has
regrown (HGI 23948). Its enormous capacity for dispersion is
thus guaranteed both in terms of sexual reproduction and the
creation of propagules (Dandelot, 2004), as observed in the
Ter basin. Although our previous research (Bou Manobens
& Font Garcia, 2016) dealt with more or less fragmented
population centres throughout the basin, in the summer of
2018 it was observed that the populations had increased their
Figure 2. Detailed photograph of the stipules of a) L. grandiora subsp. hexapetala in the Ebre River from Amposta, and b) L. peploides subsp.
montevidensis from Girona. The presence of stipules and trichomes on the stem is a distinguishing character for this subspecies of L. peploides.
Figure 3. Flowers of a) L. grandiora subsp. hexapetala from Amposta, and b) L. peploides subsp. montevidensis from Girona.
a b
Butlletí ICHN 83, 2019
continuity (Fig. 1b), from the lower part of the Onyar River,
around Quart, to the mouth of the Ter River, at Torroella de
Montgrí. The rapid expansion of this taxon in Catalonia, par-
ticularly in the Ter basin, and the various impacts evident in
other European countries (Dandelot, 2004; Dandelot et al.,
2005, 2008; Robert et al., 2013), highlight the need to clas-
sify this species as a major threat to Catalonia’s aquatic eco-
To identify the samples collected in this study, not only
have we studied morphological characters, which have some-
times led to confusion in our area (Bou Manobens & Font
Garcia, 2016), but we have also counted the number of chro-
mosomes to remove any doubt, as the two taxa are different
in this respect (Dandelot, 2004). L. grandiora subsp. hexa-
petala is decaploid, whereas L. peploides subsp. monteviden-
sis is diploid (Zardini et al., 1991a,b). All the studied popula-
tions were analysed using the “Plateforme de Cytogénétique
Moléculaire Végétale” (PCMV; Molecular Cytogenics Plat-
form) at the INRA, in Le Rheu (France). All the plants at-
tributed to L. peploides subsp. montevidensis have 16 chro-
mosomes, while L. grandiora subsp. hexapetala from the
Ebre River has 80 chromosomes. In order to clarify the dif-
ferences, the following identication key is proposed:
1 Elongated stipules (Fig. 2a). Sepals persistent on the fruit,
more than 18 mm long. Flowering stems and pedicels
with patent hairs 1-2 mm long. Leaves of the owering
stems lanceolate to almost obovate-lanceolate, dull, 4-12
cm long. Petals (12)15-23 mm long (Fig. 3a). Small sto-
mata 28±3 µm. Chromosomes 2n=80 (Fig. 4a) ................
......................................L. grandiora subsp. hexapetala
Reniform stipules (Fig. 2b). Sepals persistent on the fruit,
more than 10 mm long. Flowering stems and pedicels with
patent hairs 0.5-1 mm long. Leaves of the owering stems
obovate-oblong to almost elliptical-oblong, shiny, 3-6 cm
long. Petals 10-18 mm long (Fig. 3b). Stomata 19±2 µm.
Chromosomes 2n=16 (Fig. 4b) .........................................
....................................L. peploides subsp. montevidensis
Over recent years, the dynamics of both species have been
representing a serious threat to the biodiversity of aquatic
ecosystems, demonstrating the need for new studies on these
invasive hydrophytes. In order to efciently manage and con-
trol them, we need to more precisely understand the popula-
tion dynamics and impacts of these invasive species, while
also focusing on their origins and population genetics.
We would like to thank Olivier Coriton, Virginie Huteau,
and Dominique Barloy from the INRA and Agrocampus Ou-
est Rennes for their assistance in obtaining karyotype photo-
graphs of the samples.
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vertit en abocadors incontrolats. El Gerió Digital. Disponible en:
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stitució Catalana d’Història Natural, 80: 57–58.
CABI. 2019. Invasive Species Compendium Datasheets. Disponi-
ble en: [Data de consulta: 8/02/2019]
DANDELOT, S. 2004. Les Ludwigia spp. invasives du sud de la
France: historique, biosystematique, biologie et ecologie. Uni-
versite Paul Cezanne Aix-Marseille. 207 p.
& CAZAUBON, A. 2005. Temporal variations of physicochemi-
cal and microbiological parameters in three freshwater ecosys-
tems (southeastern France) invaded by Ludwigia spp. Comptes
Rendus Biologies, 328 (10–11): 991–999.
VERLAQUE, R. 2008. Allelopathic potential of two invasive al-
ien Ludwigia spp. Aquatic Botany, 88: 311–316.
Figure 4. Somatic metafase chromosomes of a) L. grandiora subsp. hexapetala from Amposta, and b) L. peploides subsp. montevidensis from
a b
Butlletí ICHN 83, 2019
BERT, E., GILET, H., LACROIX, P. & MAMAN, L. 2006. Ges-
tion des plantes exotiques envahissantes - Guide technique. 2nd
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FELINER, G.; PAIVA, J.; BENEDÍ, C. (eds.). Flora iberica 8:
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& DELSINNE, T. 2013. Risk analysis of the Water Primrose
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GARCÍA-MURILLO, P. 2017. An invasion risk map for non-
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Jardín Botánico de Madrid, 74: 055.
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on the middle Loire River, France. Aquatic Botany, 90: 143–148.
VERLOOVE, F. & SÁNCHEZ, E. 2008. New records of interesting
xenophytes in the Iberian Peninsula. Acta Botanica Malacitana,
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ZARDINI, E.M., GU, H. & RAVEN, P. H. 1991a. On the separation
of two species within the Ludwigia uruguayensis complex (Ona-
graceae). Systematic Biology, 16: 242–244.
ZARDINI, E. M., PENG, C. & HOCH, P. C. 1991b. Chromosome
Numbers in lu d w i g i a sect. Oligospermum and sect. oo c a r p o n
(Onagraceae). Taxon, 40: 221.
... 698, 195 m, herbassars al marge del torrent i la carretera de la Mútua (Fig. 3a) Hidròfit d'origen americà introduït amb finalitats ornamentals a diversos països europeus i que té un fort comportament invasor. Recentment, s'han publicat dos treballs que revisen la situació de les espècies del gènere Ludwigia allòctones a Catalunya (Bou & Font, 2016. Bou et al., 2019. De Ludwigia peploides subsp. montevidensis indiquen diverses poblacions (en hàbitats naturals o en hàbitats artificials) a les comarques gironines, una al delta de l'Ebre i una altra riu Llobregat, al Prat de Llobregat. La nova localitat que indiquem a les llacunes de can Duran correspon a la segona localitat per a les comarques barcel ...
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Ludwigia peploides (Kunth) Raven ssp. montevidensis (Spreng.) Raven and Ludwigia grandiflora (Michaux) Greuter and Burdet ssp. hexapetala (Hooker and Arn.) Nesom and Kartesz, are expanding their geographic range due to clonal reproduction; these taxa are considered the most important nuisance aquatic plants in French river habitats. During 1970s, these two species have colonized former channels and river banks of the middle Loire River, previously scarcely covered by aquatic vegetation. Now, the exotic Ludwigia build up dense and continuous stands with potentially high impact on biodiversity and sedimentation rates.
Zardini E. M., Peng, C.‐I & Hoch, P. C.: Chromosome numbers in Ludwigia sect Oligospermum and sect. Oocarpon (Onagraceae). ‐ Taxon 40: 221–230. 1991. ‐ ISSN 0040‐0262. Chromosome numbers are reported from all nine species (12 taxa) of Ludwigia sect. Oligospermum and sect. Oocarpon , including three not reported previously: L. hookeri ( 2n = 32), L. peduncularis ( 2n = 32), both of L. sect. Oligospermum , and L. torulosa ( 2n = 16) of the monotypic L. sect. Oocarpon. An earlier count of n = 8 for L. hookeri was based on a mis‐identified specimen of L. peploides. Counts are also reported for three naturally occurring hybrids. Chromosome counts from a total of 141 strains are included, with full voucher information for each. New data are compared with all previous reports for the species of these sections.
In earlier chromosomal studies, hexaploid (n = 24) and decaploid (n = 40) strains were reported within the species that has been called Ludwigia uruguayensis. Field observations and morphological studies of extensive living collections for which chromosome numbers are available have confirmed that these entities are best treated as two discrete species. The hexaploid species, L. grandiflora, comb. nov., has villous pubescence, sublance???? leaves with a glandular mucronate apex, smaller flowers, and smaller pollen grains. The decaploid species, L. hexapetala, comb. nov., is usually glabrous, with oblanceolate leaves, larger flowers, and larger pollen grains. Octoploid (2n = 64) hybrids between them have been found in southern Brazil and are to be expected wherever they occur together.
The allelopathic potential of two invasive alien Ludwigia [Onagraceae: L. peploides (Kunth) Raven and L. grandiflora (Michaux) Greuter and Burdet], that have developed quasi-monotypic stands in many aquatic ecosystems in France, was investigated. Since allelopathy involves the release of compounds into the environment, the water of monospecific experimental cultures was directly tested against two target species: Lactuca sativa L., the standard cultivar for bioassays, and Nasturtium officinale R. Brown, a resistant and widespread native hydrophyte. The treatment was carried out at the three main phases of development of both Ludwigia in February, May and August. For each experiment, the germination, mortality and culture yield percentages, the seedling growth (radicle and hypocotyl elongation) and the health of 15-day-old-seedlings were measured. The water of each Ludwigia tank induced: (1) a decrease in germination for watercress in August (control: 68.6%, L. peploides: 48.6%, L. grandiflora: 61.1%); (2) an increase in mortality in May only for watercress (control: 3.4%, L. peploides: 13.5%, L. grandiflora: 12%) and in August for both target species (up to 22.3% vs. 3% for lettuce and 27% vs. 12.5% for watercress); (3) a disturbance of seedling elongation for lettuce in all seasons; and (4) a seedling chlorosis of both target species, particularly in May and August. This study showed that L. peploides and L. grandiflora possess an allelopathic activity that influences the water quality throughout the year. Combined with the various competitive attributes, allelopathy may contribute to the great success of these two invasive Ludwigia in Europe. In threatened wetland communities of the Mediterranean area, in particular, allelopathy might have an important impact by diminishing the seedling survival of the most vulnerable species.
In France, two amphibious hydrophytes of alien Ludwigia (Onagraceae) have for about the past twenty years been causing serious ecological and economic problems: L. peploides (Kunth) Raven et L. grandiflora (Michaux) Greuter & Burdet. This bacteriological and physicochemical study, focused on three different Mediterranean aquatic ecosystems, reveals, for the first time, a direct negative impact of these American invaders. During summer, while plant growth is intensive, and the appearance in the water column of anoxic conditions and production of toxic compounds may be observed, notably in L. grandiflora stands. The toxicity is linked to a proliferation of sulphate-reducing bacteria producing sulphides that are very harmful for aquatic organisms.
Netegen dues basses dels Aiguamolls que s'havien convertit en abocadors incontrolats
  • Acn
ACN. 2016. Netegen dues basses dels Aiguamolls que s'havien convertit en abocadors incontrolats. El Gerió Digital. Disponible en: [Data de consulta: 1/02/2019]