ARTÍCULO

New records of alien vascular plants in Catalonia (NE Iberian Peninsula)

C. GÓMEZ-BELLVER¹, H. ÁLVAREZ², N. NUALART³, N. IBÁÑEZ³, L. SÁEZ⁴ & J. LÓPEZ-PUJOL³

¹ Unit of Botany and Mycology, Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, av. Diagonal, 643, ES-08028 Barcelona, Catalonia, Spain

² Ministry of Agriculture, Livestock, Fisheries and Food, Government of Catalonia, c. Tints, 13, ES-08830 Sant Boi de Llobregat, Catalonia, Spain

³ Botanic Institute of de Barcelona (IBB, CSIC-ICUB), pg. del Migdia, s/n, ES-08038 Barcelona, Catalonia, Spain

⁴ Universitat Autònoma de Barcelona. Systematics and Evolution of Vascular Plants, Associated Unit to CSIC, Unitat de Botànica, Facultat de Biociències, ES-08193 Bellaterra, Catalonia, Spain

ORCID iD. C. GÓMEZ-BELLVER: http://orcid.org/0000-0002-2468-158X, H. ÁLVAREZ: http://orcid.org/0000-0003-3384-9003, N. NUALART: http://orcid.org/0000-0001-5804-387X, N. IBÁÑEZ: http://orcid.org/0000-0001-8228-4016, L. SÁEZ: http://orcid.org/0000-0003-4551-2432, J. LÓPEZ-PUJOL: http://orcid.org/0000-0002-2091-6222

Author for correspondence: C. Gómez-Bellver (cgomezbellver@gmail.com)

Editor: M. Galbany-Casals

New records of alien vascular plants in Catalonia (NE Iberian Peninsula)

ABSTRACT
New records of alien vascular plants in Catalonia (NE Iberian Peninsula).— We provide the first records of five non-native vascular plants for Europe—Commelina erecta, Cylindropuntia fulgida, Dasylirion serratifolium, ×Graptosedum and Senecio crassissimus, two for the Iberian Peninsula—Lobelia laxiflora subsp. angustifolia and Pennisetum flaccidum, and four for Catalonia— Dimorphotheca fruticosa, ×Gasteraloe beguinii, Opuntia elatior and Tradescantia sillamontana. In addition, new local records are provided for ten taxa scarcely reported for Catalonia. During the last decades, ornamental horticulture constitutes the most important source of alien plants, and some of them are potentially invasive species at a worldwide level. Most of the plants listed in this study are escaped from gardens or established as a consequence of dumping green waste. Some species are locally naturalized and in some cases they could behave as invasive.
KEY WORDS: Catalonia; introduced plants; naturalized; non-native.

Nuevas citas de plantas vasculares alóctonas en Cataluña (NE de la península ibérica)

RESUMEN
Nuevas citas de plantas vasculares alóctonas en Cataluña (NE de la península ibérica).— Aportamos citas de cinco plantas alóctonas nuevas para Europa —Commelina erecta, Cylindropuntia fulgida, Dasylirion serratifolium, ×Graptosedum y Senecio crassissimus—, dos nuevas para la península ibérica —Lobelia laxiflora subsp. angustifolia y Pennisetum flaccidum— y cuatro nuevas para Cataluña —Dimorphotheca fruticosa, ×Gasteraloe beguinii, Opuntia elatior y Tradescantia sillamontana—. También presentamos nuevos datos sobre diez plantas poco citadas en Cataluña. En las últimas décadas el cultivo de plantas ornamentales constituye la principal causa de introducción de especies alóctonas a escala mundial, algunas de las cuales son potencialmente invasoras. La mayoría de las plantas que constan en este trabajo son escapadas de cultivos o provienen de vertidos de restos de jardinería. Algunas especies se encuentran localmente naturalizadas y en algún caso podrían presentar un comportamiento invasor.
PALABRAS CLAVE: Cataluña; flora alóctona; plantas introducidas; plantas naturalizadas.

CONTENIDOS

INTRODUCTIONTop

Catalonia, located to the west of the Mediterranean Basin, is a region with a remarkable biological biodiversity, but also where plant invasions are particularly significant (Bresch et al., 2013Bresch, C., Mailleret, L., Muller, M. M., Poncet, C. & Parolin, P. 2013. Invasive plants in the Mediterranean basin: which traits do they share? Journal of Mediterranean Ecology 12: 13–19. ). These introductions are caused by human action, either intentionally or accidentally. Mainly during the last decades, ornamental horticulture constitutes the most important source of alien and potentially invasive species at a worldwide level (Groves et al., 2005Groves, R. H., Boden, R. & Lonsdale, W. M. 2005. Jumping the garden fence: Invasive garden plants in Australia and their environmental and agricultural impacts. CSIRO report prepared for WWF-Australia. WWF-Australia, Sydney.; Dehnen-Schmutz & Touza, 2008Dehnen-Schmutz, K. & Touza, J. 2008. Plant invasions and ornamental horticulture: pathway, propagule pressure and the legal framework. Floriculture, Ornamental and Plant Biotechnology Advances and Topical Issues 5: 15–21.; Pergl et al., 2016Pergl, J., Sádlo, J., Petřík, P. et al. 2016. Dark side of the fence: ornamental plants as a source of wildgrowing flora in the Czech Republic. Preslia 88: 163–184. ; Mayer et al., 2017Mayer, K., Haeuser, E., Dawson, W. et al. 2017. Naturalization of ornamental plant species in public green spaces and private gardens. Biological Invasions 9: 3613–3627. https://doi.org/10.1007/s10530-017-1594-y ), particularly in the face of a warming climate perspective (Dullinger et al., 2017Dullinger, I., Wessely, J., Bossdorf, O. et al. 2017. Climate change will increase the naturalization risk from garden plants in Europe. Global Ecology and Biogeography 26: 43–53. https://doi.org/10.1111/geb.12512). Today, cities are considered hotspots of biological invasions, not only points of entry for many non-native species, but also foci for secondary release or escape into surrounding landscapes (Lososová et al., 2012Lososová, Z., Chytrý, M., Tichý, L. et al. 2012. Native and alien floras in urban habitats: a comparison across 32 cities of central Europe. Global Ecology and Biogeography 21: 545–555. https://doi.org/10.1111/j.1466-8238.2011.00704.x; Gaertner et al., 2017Gaertner, M., Wilson, J. R. U., Cadotte, M. W. et al. 2017. Non-native species in urban environments: patterns, processes, impacts and challenges. Biological Invasions 19: 3461–3469. https://doi.org/10.1007/s10530-017-1598-7). This concept is illustrated in the present work; most of the plants that we provide are escaped from gardens or established as a consequence of dumping green waste and found in areas near large human populations.

It is generally accepted that an early detection of new xenophytes is essential. However, this requires a prospecting effort to detect overlooked non-native plants in a given territory and their accurate determination (Verloove, 2010Verloove, F. 2010. Invaders in disguise: conservation risks derived from misidentifications of invasive plants. Management of Biological Invasions 1: 1–5. https://doi.org/10.3391/mbi.2010.1.1.02). The decline in taxonomic expertise substantially compromises rigorous studies in all fields of biodiversity or biogeography, including invasion biology (Pyšek et al., 2013Pyšek, P., Hulme, P. E., Meyerson, L. A. et al. 2013. Hitting the right target: taxonomic challenges for, and of, plant invasions. AoB PLANTS 5: plt042. https://doi.org/10.1093/aobpla/plt042). Intensive fieldwork and an accurate knowledge of the identity of these species are fundamental to ascertain their real distribution and behaviour within the ecosystems. Likewise, monographs and more general studies that provide taxonomic and biological information of the new or scarcely known non-native plants are key tools for plant invasions research and management purposes (Smith et al., 2008Smith, R. D., Aradottir, G. I., Taylor, A. & Lyal, C. 2008. Invasive species management – what taxonomic support is needed? Global Invasive Species Programme, Nairobi. ).

MATERIALS AND METHODSTop

The records presented here are the result of recent years’ fieldwork in Catalonia, within a project to survey and catalogue its alien flora, especially on coastal areas. At least one voucher specimen is preserved in BC or BCN herbaria except for Clerodendrum bungei Steud., Crocus sativus L., Echinopsis spachiana (Lem.) H. Friedrich & G. D. Rowley, ×Graptosedum G. D. Rowley, Haworthiopsis attenuata (Haw.) Rowley and Opuntia leucotricha DC. Photographs were taken for all the species. Acronyms follow Index Herbariorum (Thiers, 2013Thiers, B. 2013. Index Herbariorum: A global directory of public herbaria and associated staff. The New York Botanical Garden, New York. Retrieved December, 2017, from http://sweetgum.nybg.org/ih/). The names of families are based on the APG IV (APG, 2016APG [Angiosperm Phylogeny Group] 2016. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of the Linnean Society 181: 1–20. https://doi.org/10.1111/boj.12385 ).

Plants are arranged following alphabetical order of genera. We used the standardized terminology to define the status of the alien plants proposed by Pyšek et al. (2004Pyšek, P., Richardson, D. M., Rejmánek, M., Webster G. L., Williamson, M. & Kirschner, J. 2004. Alien plants in checklists and floras: towards better communication between taxonomists and ecologists. Taxon 53:131–143. https://doi.org/10.2307/4135498) and Gassó (2008Gassó, N. 2008. Plant invasion success in Spain: a macroecological approach. PhD Thesis, Universitat Autònoma de Barcelona, Barcelona.); a given plant species can be ‘casual’ (it can reproduce occasionally outside cultivation but does not form self-replacing populations for at least 10 years) or ‘naturalized’ (that sustain self-replacing populations without direct human intervention, capable of independent growth). All the taxa presented here can be considered casual; only Opuntia leucotricha is sometimes locally naturalized. Among the species reported here, we did not find any case of ‘invasive’ plant within our territory, but a few of them could behave as invasive species in the near future; this is likely the case of Cylindropuntia fulgida (Engelm.) F. M. Knuth. For each species we provide the sort of novelty, main details of the records and some comments about the native range, and its distribution in our territory. A brief morphological description is also provided in those cases we consider it proper.

Each record includes province, county (in Catalonia known as comarca) and locality, according to the names published in ICGC (http://www.icc.cat/vissir3/). For the geographic reference we used the 100 × 100 m UTM square grid (31T zone), ETRS89 datum.

RESULTSTop

Asclepias curassavica L. (Fig. 1A) (Apocynaceae).

Second record for Catalonia.

Barcelona, el Baix Llobregat: Santa Coloma de Cervelló, Can Julià, wasteland near the road, in a shady and fresh ditch, two separate individuals in blossom, approximately 60 cm in length, DF183796, 40 m, 30.X.2016, H. Álvarez (BC 990387, BCN 134530, BCN 134531). Although this species was found near some houses with gardens, we have verified that it is not planted.

Herb or sub-shrub native to the American tropics that grows up to 1 m (Juárez-Jaimes & Lozada, 2003Juárez-Jaimes, V. & Lozada, L. 2003. Flora del Valle de Tehuacán-Cuicatlán 37. Asclepiadaceae. Instituto de Biología (Universidad Nacional Autónoma de México), México D. F. ), commonly used as an ornamental plant because of its showy red flowers. We provide the second report for Catalonia. It was formerly reported from Barcelonès county (Bolòs & Vigo, 1996Bolòs, O. de & Vigo, J. 1996. Flora dels Països Catalans 3. Barcino, Barcelona.). It is also known as subpontaneous or naturalized for the rest of the east coast and the south of the Iberian Peninsula (Arista & Ortiz, 2012Arista, M. & Ortiz, P. L. 2012. Asclepiadaceae. In: Castroviejo, S., Talavera, S., Andrés, M. C. et al. (Eds.), Flora iberica 11. Real Jardín Botánico (CSIC), Madrid: 110–133. —without any indication as to whether the plants were cultivated or not; Sanz-Elorza et al., 2004aSanz-Elorza, M., Dana, E. D. & Sobrino, E. 2004a. Atlas de las plantas alóctonas invasoras en España. Dirección General para la Biodiversidad (Ministerio de Medio Ambiente), Madrid.). It is considered an invasive plant in Australia, New Zealand, United States, Chile, the Pacific Islands (Sanz-Elorza et al., 2004a) and South Africa (Foxcroft et al., 2007Foxcroft, L. C., Richardson, D. M. & Wilson, J. R. U. 2007. Ornamental plants as invasive aliens: problems and solutions in Kruger National Park, South Africa. Environmental Management 41: 32–51. https://doi.org/10.1007/s00267-007-9027-9).

Clerodendrum bungei Steud. (Fig. 1B) (Lamiaceae).

Third record for Catalonia.

Tarragona, el Baix Ebre: Tortosa, Vinallop, several plants, in bloom, in a wayside next to an old house, BF900167, 31 m, 19.VII.2016, J. Altimira (no voucher available).

Deciduous shrub, native to southern China and northern India. It has recently been reported for Catalonia by Aymerich (2016Aymerich, P. 2016. Contribució al coneixement de la flora al·lòctona del nord i el centre de Catalunya. Orsis 30: 11–40. https://doi.org/10.5565/rev/orsis.26) in Girona Province, as casual, perhaps as a result of dirt disposal, and in Tarragona Province, in a ruderal community near a house.

Commelina erecta L. (Fig. 1C) (Commelinaceae).

New to Europe.

Barcelona, el Baix Llobregat: Santa Coloma de Cervelló, Ca n’Isbert, small group in a ruderal grassland on sandy soil, near a railway, DF186800, 18 m, 07.X.2016, H. Álvarez (BC 990389, BCN 134535, BCN 134536); ibid., 30.X.2016, H. Álvarez (BC 990390, BCN 134534). El Maresme: Vilassar de Mar, riera de Cabrils, a crowded population of large specimens in an area of ca. 10 m² in nitrophilous grassland on sandy soil, close to some flower nurseries, DF486952, 33 m, 18.VIII.2017, H. Álvarez (BC 990549, BCN 143480). All specimens were found growing in bloom and producing seeds.

Perennial herbaceous plant, very variable (Brashier, 1966Brashier, C. K. 1966. A revision of Commelina (Plum.) L. in the U.S.A. Bulletin of the Torrey Botanical Club 93: 1–19. https://doi.org/10.2307/2483882), native to America (from southern United States to Argentina; Hunt, 1994Hunt, D. R. 1994. Commelinaceae. In: Davidse, G., Sousa, M. & Chater, A. O. (Eds.), Flora Mesoamericana 6. Universidad Autónoma de México, México, D. F., Missouri Botanical Garden, St. Louis & The Natural History Museum, London: 157–173.), and used for medicinal, food and ornamental purposes. It is regarded as a crop weed, and it has been introduced in other South American countries, in a considerable part of central and southern Africa—including the north of Madagascar, and in the south of the Arabian Peninsula (GBIF, 2017a)GBIF [Global Biodiversity Information Facility] 2017a. Commelina erecta L. Retrieved January 9, 2018, from https://www.gbif.org/species/2764389. https://doi.org/10.15468/dl.vqjq0q. It has also been reported from Japan (Nakamura, 2017Nakamura, I. 2017. Note on Commelina erecta (Commelinaceae) naturalized in Naniwano-Miya Historical Park, Osaka Prefecture, Japan. Journal of Japanese Botany 92: 123–126. ) and, in the east of the Mediterranean Basin, in Israel (Raab-Straube & Raus, 2015Raab-Straube, E. Von & Raus, T. (Eds.) 2015. Euro+Med-Checklist Notulae, 4 [Notulae ad floram euro-mediterraneam pertinentes 33]. Willdenowia 45: 119–129. https://doi.org/10.3372/wi.45.45113). In Catalonia, another alien congeneric species, C. communis L., was reported from northern Girona (Font & Vilar, 2000Font, J. & Vilar, L. 2000. Plantes vasculars del quadrat UTM 31T DG99. Sant Climent Sescebes (Catàlegs Florístics Locals, 10). Secció de Ciències Biològiques (Institut d’Estudis Catalans), Barcelona.). It is an annual herb with similar inflorescences in appearance, but enclosed in spathes with free margins, unlike C. erecta in which spathes are partially connate towards the apex.

We provide the first record for Europe of this plant, and most likely the second for the Mediterranean Basin. Its global distribution, as well as its tolerance to glyphosate treatment (De la Vega et al., 2000De la Vega, M. H., Lemir, A. H. M., García, A. E., Pace, R. & Aceñolaza, M. 2000. Control de Commelina erecta L. con herbicidas postemergentes con el objetivo de su uso en cultivos de soja transgénica. Planta Daninha 18: 51–56. http://dx.doi.org/10.1590/S0100-83582000000100005), make this species a potential invasive plant in our area.

Crocus sativus L. (Fig. 1D) (Iridaceae).

New for the province of Barcelona.

Barcelona, el Baix Llobregat: Sant Feliu del Llobregat, riera de Santa Creu, two specimens in full bloom, in a ruderalized meadow on the banks of the stream, DF213834, 90 m, 12.XI.2016, H. Álvarez (no voucher available). Presumably, a recent wild boar feeding activity did not allow us to subsequently locate the plants for the purpose of collecting them.

This bulbous geophyte is highly regarded as a spice for its dried stigmas and styles, the saffron. It is a triploid species (2n = 24) and a sterile plant. Its cultivation is very old, dating back to 2500–1500 BC, probably originated in Iran, Asia Minor or Greece and later became widespread in India, China, the Mediterranean basin and Eastern Europe (Ghaffari & Bagheri, 2009Ghaffari, S. M. & Bagheri, A. 2009. Stigma variability in saffron (Crocus sativus L.). African Journal of Biotechnology 8: 601–604.; Martín, 2014Martín, G. 2014. Azafrán I (Crocus sativus L.). Reduca (Biología). Serie Botánica 7: 71–83. ).

The cultivation of saffron in Catalonia was quite common from the late 19th until the late 20th century, and since then the plant is considered as persistent in abandoned crops, or escaped from them. As reported in Casasayas (1989Casasayas, T. 1989. La flora al·lòctona de Catalunya. Catàleg raonat de les plantes vasculars exòtiques que creixen sense cultiu al NE de la Península Ibèrica. PhD Thesis, Universitat de Barcelona, Barcelona.), it has already been observed in Girona, Lleida and Tarragona provinces. The species had not been recorded for the last 33 years so far, probably because the populations of this archaeophyte have been declining for decades due to the cessation of its production.

Figure 1. (A), Asclepias curassavica, Santa Coloma de Cervelló; (B), Clerodendrum bungei, Tortosa; (C), Commelina erecta, Vilassar de Mar; (D), Crocus sativus, Sant Feliu del Llobregat (photographs A, C, D: H. Álvarez; B: J. Altimira). [View full size] [Descargar tamaño completo]

Cylindropuntia fulgida (Engelm.) F. M. Knuth (Fig. 2A) (Cactaceae).

New to Europe.

Tarragona, el Montsià: Alcanar, at the town’s entrance, a group of numerous plants up to 30 cm in height, ca. 3 m along the roadside, BE865916, 95 m, 18.VII.2016, C. Gómez-Bellver, J. López-Pujol & N. Nualart (BC 956117).

The native range of C. fulgida extends from the desert of Sonora in Arizona, to Sinaloa and Baja California in Mexico (Anderson, 2001Anderson, E. F. 2001. The cactus family. Timber Press, Portland.). There are several species of Cylindropuntia in the centre and north of the Iberian Mediterranean coast; the three species with the largest distribution are C. imbricata (Haw.) F. M. Knuth, C. tunicata (Lehm.) F. M. Knuth and C. pallida (Rose) F. M. Knuth (Deltoro et al., 2014Deltoro, V., Gómez-Serrano, M. A., Laguna, E. & Novoa A. 2014. Bases para el control del cactus invasor Cylindropuntia pallida. (Colección Manuales Técnicos de Biodiversidad, 5). Conselleria d’Infraestructures, Territori i Medi Ambient (Generalitat Valenciana), València. ), from which C. fulgida can be distinguished by its fruits proliferating in chains (Walters et al., 2011Walters, M., Figueiredo, E., Crouch, N. R. et al. 2011. Naturalised and invasive succulents of southern Africa (ABC Taxa, 11). The Belgian Development Cooperation, Brussels.). The specimens collected correspond to the ‘mamillata’ variety, smaller, more compact and tuberculated than the typical, and to the ‘monstrous’ form, one of the two that are known in gardening, together with ‘cristata’. We noticed that the terminal parts easily disarticulate, forming propagules that stick to the clothes or the skin thanks to long and fine spines. We presume that these forms lack fertile seeds.

Cylindropuntia fulgida is treated as an invasive species in Australia (where the ‘mamillata’ variety is considered the most rapidly spreading opuntioid cactus in the country), South Africa (where the typical variety is one of the most invasive cacti) and Pacific Islands (Lloyd & Reeves, 2014Lloyd, S. & Reeves, A. 2014. Situation statement on opuntioid cacti (Austrocylindropuntia spp., Cylindropuntia spp. and Opuntia spp.) in Western Australia. Department of Agriculture and Food (Goverment of Western Australia), Perth. ; Walters et al., 2011Walters, M., Figueiredo, E., Crouch, N. R. et al. 2011. Naturalised and invasive succulents of southern Africa (ABC Taxa, 11). The Belgian Development Cooperation, Brussels.). Deltoro et al. (2014Deltoro, V., Gómez-Serrano, M. A., Laguna, E. & Novoa A. 2014. Bases para el control del cactus invasor Cylindropuntia pallida. (Colección Manuales Técnicos de Biodiversidad, 5). Conselleria d’Infraestructures, Territori i Medi Ambient (Generalitat Valenciana), València. ) already warned that this plant, in the case of its arrival to Europe, could be even more invasive than other described cacti of the same genus.

Dasylirion serratifolium (Karw. ex Schult. f.) Zucc. (Fig. 2B) (Asparagaceae).

New to Europe.

Girona, l’Alt Empordà: Darnius, el Mirador, a couple of large individuals in a relatively human-disturbed area near the Boadella Dam, perhaps persisting after cultivation (although there are no signs of management), DG862874, 180 m, 10.III.2018, J. López-Pujol (BC 971857). Tarragona, el Tarragonès: Tarragona, Cala Romana, only one plant in a ruderal road margin, CF560540, 23 m, 20.II.2017, S. Herrando & N. Nualart (BC 958020).

Mexican plant similar in appearance to yucca, with very narrow and long leaves, with marginal hooked prickles and ending in a fibrous tip (Walker, 2001Walker, C. C. 2001. Nolina. In: Eggli, U. (Ed.), Illustrated handbook of succulent plants: Monocotyledons. Springer-Verlag, Berlin: 291–292.). In Catalonia and nearby regions several species of Dasylirion Zucc. are commonly grown in gardens and also sold by nurseries and garden centres. Among those, D. serratifolium is the most well-known species, but others should also be mentioned: Dasylirion longissimum Lemaire with quadrangular leaves, which appears in the European list of wild fauna and flora species with regulating trade therein (EU, 2013EU [European Union] 2013. EU Commission Regulation No 750/2013 of 29 July 2013 amending Council Regulation (EC) No 338/97 on the protection of species of wild fauna and flora. Official Journal of the European Union L212: 1–92.), D. glaucophyllum Hook., with glaucous leaves and pointed apex (or almost) and D. wheeleri S. Watson, with long and thick stem.

Dimorphotheca fruticosa (L.) DC. (Fig. 2C) (Asteraceae).

First record for Catalonia.

Girona, l’Alt Empordà: l’Escala, northwest part of the municipality, in a neighborhood of terraced houses, close to the road GI-623, a prostrate dense formation covering ca. 5 m², on rocky sandy soil, EG102629, 26 m, 22.II.2018, C. Gómez-Bellver, J. López-Pujol & N. Ibáñez (BC 990589).

Shortly hairy, sprawling to prostrate, softy woody shrublet native to South Africa’s coastal dunes and rocks (Manning & Goldblatt, 2012Manning, J. & Goldblatt, P. 2012. Plants of the Greater Cape floristic region 1: The core Cape flora (Strelitzia, 29). South African National Biodiversity Institute, Pretoria.). Leaves are obovate, fleshy, minutely toothed and the flowers purple. In the Iberian Peninsula, it has been reported as casual for the Valencia Province (Peña et al., 2017Peña, A., Ferrer-Gallego, P. P., Riera, J., Fabado, J. & Mateo, G. 2017. Flora vascular del Parc Natural del Túria. Jolube Consultor Botánico y Editor, Jaca.).

Echinopsis spachiana(Lem.) H. Friedrich & G. D. Rowley (Fig. 2D–E) (Cactaceae).

Third record for Catalonia.

Tarragona, el Baix Ebre: Roquetes, Mas d’en Sedó, near the ravine of Sant Antoni, west of Tortosa, group of 6–7 adult plants with withered flowers, and two juveniles, on one side of the road, on the top of the slope, presumably coming from green waste, BF878185, 45 m, 18.VII.2016, C. Gómez-Bellver, J. López-Pujol & N. Nualart (no voucher available).

Columnar cactus native to western Argentina, quite used in gardening. Plant with a central trunk up to 2 m tall, branching basally, with 10–15 ribs, and a central spine in each areola noticeably longer than the rest (Britton & Rose, 1920Britton, N. L. & Rose, J. N. 1920. The Cactaceae 2. The Carnegie Institution, Washington D. C. https://doi.org/10.5962/bhl.title.46288; Anderson, 2001Anderson, E. F. 2001. The cactus family. Timber Press, Portland.; Hunt, 2011Hunt, D. R. 2011. Echinopsis. In: Cullen, J., Knees, S. & Cubey, H. S. (Eds.), The European garden flora 2. Casuarinaceae to Cruciferae (2nd ed.). Cambridge University Press, Cambridge: 249–254. ). When young it can be confused with E. schickendantzii F. A. C. Weber, which does not exceed 15–25 cm, and has 14–18 ribs. Our plants reach a height of 1.50 m, display few branches, 13 ribs, and a central spine longer than the rest in each areola.

This species was reported for Catalonia by Aymerich (2015Aymerich, P. 2015. Contribución al conocimiento de las cactáceas en Cataluña. Bouteloua 22: 76–98. , 2017Aymerich, P. 2017. Notes sobre flora al·lòctona a Catalunya. Butlletí de la Institució Catalana d’Història Natural 81: 97–116. ) from the province of Barcelona—in similar conditions to our finding: a group of established plants in a slope resulting from a dumping of yard trimmings—and Girona.

×Gasteraloe beguinii (Radl) Guillaumin (Fig. 2F–G) (Asphodelaceae).

New to Catalonia.

Tarragona, el Baix Penedès: Bellvei, in the roadside (road N-340), near habitation, a dense colony of about 2 m² and a few individuals 1–2 m away, several carrying inflorescences, growing with other non-native plants including Opuntia leucotricha DC. and O. monacantha Haw., CF808661, 95 m, 23.XII.2017, J. López-Pujol (BC 953811, BCN 143481).

Intergeneric hybrid between Aloe aristata Haw. and Gasteria carinata (Mill.) Duval var. verrucosa (Mill.) van Jaarsv., both native to South Africa and nearby territories. Larger and coarser than A. aristata, the leaves of this hybrid are 10 × 2.5 cm (noticeably bigger in some nothovarieties, reaching 16 cm long), dark green, with prominent scattered white pearly tubercles; the inflorescence is a terminal lax and simple raceme up to 60 cm (Newton, 2001Newton, L. E. 2001. ×Gasteraloe. In: Eggli, U. (Ed.), Illustrated handbook of succulent plants: Monocotyledons. Springer-Verlag, Berlin: 190–192.). The individuals observed display the upper range of leaf and inflorescence size, presumably due to optimal local growing conditions.

Despite the fact that most nothospecies in ×Gasteraloe were artificially created, it is likely that this phenomenon could happen naturally or accidentally, e.g. within a nursery. In this sense, A. aristata can interbreed readily with species of Gasteria, and the resulting bigeneric hybrids produce fertile pollen, but of poor quality (Brandham, 1981Brandham, P. 1981. Aloe aristata: an underrated species. The Cactus and Succulent Journal of Great Britain 43: 3–6. ).

It has only been previously reported from the Iberian Peninsula from Huesca by Sanz-Elorza (2006Sanz-Elorza, M. 2006. La flora alóctona del Altoaragón: flora analítica de xenófitas de la provincia de Huesca. Gihemar, Madrid. ) and from Valencia by Guillot et al. (2014aGuillot, D., Ferrer-Gallego, P. P., Ferrando, I. & Laguna, E. 2014a. New records of allochthonous succulent plants of ornamental origin in the province of Valencia (Valencian Community, Spain). Xerophilia 3(11): 62–66.). We recently collected a specimen voucher (BC 947266) from the population reported by Aymerich (2017Aymerich, P. 2017. Notes sobre flora al·lòctona a Catalunya. Butlletí de la Institució Catalana d’Història Natural 81: 97–116. ) as Haworthiopsis attenuata (Haw.) Rowley from Piera (Barcelona Province). We think that it should be regarded as ×Gasteraloe beguinii, given that it is a larger plant with wider leaves possessing tubercles forming laxer and more separate lines.

×GraptosedumG. D. Rowley (Fig. 2H) (Crassulaceae).

New to Europe.

Girona, el Baix Empordà: Palamós, Punta des Molí, next to the path to the harbor, below the lighthouse, on a slope close to the sea, growing with other subspontaneous or naturalized succulent plants, such as Aeonium haworthii Webb & Berthel., Carpobrotus edulis (L.) N. E. Br. and Cotyledon macrantha A. Berger, EG106322, 5 m, 30.V.2016, C. Gómez-Bellver, J. López-Pujol & N. Nualart (no voucher available).

Intergeneric hybrid between Graptopetalum paraguayense (N. E. Br.) E. Walther, from Mexico, and a representative of the Pachysedum H. Jacobsen group, probably some species of yellow flowers of Sedum or Echeveria (Guillot et al., 2009Guillot, D., Laguna, E. & Rosselló, J. A. 2009. La familia Crassulaceae en la flora alóctona valenciana (Monografías de la revista Bouteloua, 4). Jolube Consultor y Editor Ambiental, Jaca.; Cristini, 2016Cristini, M. 2016. Graptosedum ‘Francesco Baldi’: history, diffusion and cultivation of a mysterious hybrid. Xerophilia 5: 13–26.). Presumably, this hybridization happened spontaneously in a European nursery or garden, between the early 1920s and the late 1970s (Cristini, 2016Cristini, M. 2016. Graptosedum ‘Francesco Baldi’: history, diffusion and cultivation of a mysterious hybrid. Xerophilia 5: 13–26.). Our plants are very similar to G. paraguayense, but with more intense yellow flowers and obovate to oblanceolate leaves, gray-green in color (but if growing in a sunny spot they can be tinged with red near the apex). No species has been described for this nothogenus, only some cultivars are known. The report provided here is referred to the cultivar ‘Francesco Baldi’, cited only as a cultivation escape from Nelson, New Zealand (Heenan et al., 2008Heenan, P. B., Lange, P. J. de, Cameron, E. K. & Parris, B. S. 2008. Checklist of dicotyledons, gymnosperms, and pteridophytes naturalised or casual in New Zealand: Additional records 2004–06. New Zealand Journal of Botany 46: 257–283. https://doi.org/10.1080/00288250809509765) in 1986.

Figure 2. (A), Cylindropuntia fulgida, Alcanar; (B), Dasylirion serratifolium, Darnius; (C), Dimorphotheca fruticosa, l’Escala; (D, E), Echinopsis spachiana, Roquetes; (F, G), ×Gasteraloe beguinii, Bellvei; (H), ×Graptosedum, Palamós (photographs A, C–E, H: C. Gómez-Bellver; B, F, G: J. López-Pujol). [View full size] [Descargar tamaño completo]

Haworthiopsis attenuata (Haw.) Rowley (Fig. 3A–B) (Asphodelaceae).

Second record for Catalonia.

Tarragona, el Baix Ebre: l’Ametlla de Mar, Calafat, in an open ground between Avda. de l’Atmetlla de Mar and carrer del Garbí, tiny specimen growing at the foot of a small group of Aloe perfoliata L., CF187334, 23 m, 19.VII.2016, C. Gómez-Bellver, J. López-Pujol & N. Nualart (no voucher available).

A little stemless succulent plant native to the Eastern Cape Province in South Africa. It forms rosettes of 6–10 cm in diameter, with short leaves with white tubercles on both faces, arranged roughly in bands (Bayer & van Jaarsveld, 2001Bayer, M. B. & van Jaarsveld, E. 2001. Haworthia. In: Eggli, U. (Ed.), Illustrated handbook of succulent plants: Monocotyledons. Springer-Verlag, Berlin: 199–223.). This species bears resemblance with another plant also used as an ornamental, H. fasciata (Willd.) Haworth, with white tubercles only on the lower face. It was first reported for Catalonia by Royo (2006Royo, F. 2006. Flora i vegetació de les planes i serres litorals compreses entre el riu Ebro i la serra d’Irta. PhD Thesis, Universitat de Barcelona, Barcelona. ), and later, mistakenly, by Aymerich (2017Aymerich, P. 2017. Notes sobre flora al·lòctona a Catalunya. Butlletí de la Institució Catalana d’Història Natural 81: 97–116. ) from Piera (see the text for ×Gasteraloe beguinii).

Leucaena leucocephala (Lam.) de Wit (Fig. 3C) (Fabaceae).

Second record for Catalonia.

Tarragona, el Tarragonès: Roda de Berà, Costa Daurada neighborhood, in vacant lots, a few mature individuals (including a tree of 4–5 m) and many juveniles and seedlings around, CF724596, ca. 30 m, 01.II.2018, J. López-Pujol (BC 969044).

A small to medium size fast-growing mimosoid tree native to southern Mexico and northern Central America (Belize and Guatemala). Our plant can be regarded as the subspecies glabrata (Rose) Zárate, because of the larger leaves, leaflets, and pods, and being almost entirely glabrous, compared to the smaller leaves, leaflets, pods and densely puberulent, canescent shoots of subsp. leucocephala (Zárate, 1994Zárate, S. 1994. Revisión del género Leucaena en México. Anales del Instituto de Biología de la Universidad Autónoma de México, Serie Botánica 65: 83–162.; Hughes, 1998Hughes, C. 1998. Monograph of Leucaena (Leguminosae-Mimosoideae) (Systematic Botany Monographs, 55). American Society of Plant Taxonomists, Laramie. https://doi.org/10.2307/25027876 ). Leucaena leucocephala has been cultivated since ancient times for pods in human and animal food production, and more recently also as a tropical tree for fodder, wood and soil conservation. It is spreading naturally and has been reported as a weed in more than 20 countries across all continents except Europe and Antarctica (GISD, 2015GISD [Global Invasive Species Database] 2015. Species profile Leucaena leucocephala. Retrieved December 20, 2017, from http://www.iucngisd.org/gisd/species.php?sc=23).

The species was first reported for the province of Tarragona by Casasayas (1989Casasayas, T. 1989. La flora al·lòctona de Catalunya. Catàleg raonat de les plantes vasculars exòtiques que creixen sense cultiu al NE de la Península Ibèrica. PhD Thesis, Universitat de Barcelona, Barcelona.). We provide the second record for Catalonia, located approximately 20 km northeast of the former record.

Lobelia laxiflora Kunth subsp. angustifolia (A. DC.) Eakes & Lammers (Fig. 3D) (Campanulaceae).

New to the Iberian Peninsula.

Barcelona, el Barcelonès: Barcelona, Parc del Guinardó, one plant growing in fissures in a tiny wall of a small channel of water, in blossom five years ago, and revisited in 11.II.2018 when another individual was located 30 m apart in a stone flower bed, growing as subspontaneus at the foot of a cultivated Nerium oleander L., DF305856, 134 m, 07.IV.2013, C. Gómez-Bellver & N. Marqués (BC 990563, BCN 144513).

This perennial herb is native to northeastern Mexico and southern Arizona. The subspecies angustifolia has linear-lanceolate leaves, with lamina more than 10 times longer than wide (Rzedowski & Rzedowski, 1997Rzedowski, J. & Calderón de Rzedowski, G. 1997. Campanulaceae. In: Rzedowski, J. & Calderón de Rzedowski, G. (Eds.), Flora del Bajío y de regiones adyacentes 58. Instituto de Ecología A. C.-Centro Regional del Bajío, Pátzcuaro.; Lammers, 2004Lammers, T. G. 2004. Revision of Lobelia sect. Homochilus (Campanulaceae: Lobelioideae). Sida 21: 591–623.).

In Europe Lobelia laxiflora has only been reported from Italy (Celesti-Grapow et al., 2010Celesti-Grapow, L., Pretto, F., Carli, E. & Blasi, C. (Eds.) 2010. Flora vascolare alloctona e invasiva delle regioni d’Italia. Casa Editrice Università La Sapienza, Roma. ) and the archipelago of Madeira (Vieira, 2002Vieira, R. S. 2002. Flora da Madeira. Plantas vasculares naturalizadas no Arquipélago da Madeira (Boletim do Museu Municipal do Funchal, 8). Museu Municipal do Funchal, Funchal. ), where it was considered as a casual plant.

Opuntia elatior Mill. (Fig. 3E) (Cactaceae).

First record for Catalonia.

Barcelona, el Barcelonès: Esplugues de Llobregat, Ciutat Diagonal, near to Can Moragues, a group of ca. 10 big clonal plants presumably persistent as an abandoned cultivation for some decades, up to 3.5 m height, occupying an area of 25–30 m², flowering and fruiting, and three dispersed plants no more than 1.2 m tall, relatively close to the main group, in a shrubby slope, DF244820, 172 m, 12.I.2018, H. Álvarez & C. Gómez-Bellver (BC 990588); Barcelona, Montjuïc Mountain on the Miramar side, few adults cultivated for many years besides the road, and a big subspontaneous plant, ca. 5–6 m wide, growing on a rocky slope, accompanied by Aloe ferox Mill., all flowering, DF306796, 34 m, 24.I.2018, C. Gómez-Bellver (no voucher available).

This prickly pear is native to the Antilles and part of tropical South America—Colombia and Venezuela (Bravo-Hollis & Arias, 2011Bravo-Hollis, H. & Arias, S. 2011. Flora Mesoamericana 2(1). Universidad Nacional Autónoma de México, México D. F.; Majure et al., 2017Majure, L., Griffith, P. & Nassar, J. 2017. Opuntia elatior (amended version of 2013 assessment). The IUCN Red List of Threatened Species 2017: e.T152935A121617475. Retrieved January 15, 2018, from http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T152935A121617475.en ). It has been reported for South Europe in Spain in the Balearic Islands (Serapio et al., 2016Serapio, J., Sáez, L. & Guillot, D. 2016. Opuntia bergeriana, primera cita como alóctona en las Islas Baleares. Bouteloua 26: 97–117.) and Valencia (Guillot et al., 2008Guillot, D., Laguna, E. & Rosselló, J. A. 2008. Flora alóctona valenciana: familia Cactaceae (Monografías de la revista Bouteloua, 5). Jolube Consultor y Editor Ambiental, Jaca., 2014bGuillot, D., Sánchez-Gullón, E. & Lodé, J. 2014b. Nuevas citas de cuatro cactáceas en la provincia de Valencia. Bouteloua 19: 11–17.)—both O. bergeriana Weber, based on the indications of Britton & Rose (1920Britton, N. L. & Rose, J. N. 1920. The Cactaceae 2. The Carnegie Institution, Washington D. C. https://doi.org/10.5962/bhl.title.46288)—and in Italy (Guiggi, 2008Guiggi, A. 2008. Catalogo delle Cactaceae naturalizzate in Italia con osservazioni tassonomiche, nomenclaturali e corologiche. Rivista Piemontese di Storia Naturale 29: 103–140. ). Despite some differences between the cactus seen in Europe (bright red flowers and yellowish spines, grayish when old—Berger, 1904Berger, A. 1904. New or noteworthy plants. Opuntias. The Gardeners’ Chronicle 35: 34.) and in America (flowers yellow or reddish-orange with red or rose stripes and dark brown spines, turning to gray when aged—Anderson, 2001Anderson, E. F. 2001. The cactus family. Timber Press, Portland.; Bravo-Hollis & Arias, 2014), we consider that both plants could possibly correspond to different forms of the same species. We should take into account that O. bergeriana was described from cultivated plants and, thus, the differential traits might be result of selection by gardeners. Recently, F. Verloove and A. Guiggi (pers. comm.) confirmed the identity of our plant as O. elatior.

The cladodes of the plants observed were 12–16(18) × 25–30(35) cm, with uneven spines yellow to pale brown-red, usually the older whitish to gray, 0–4(5) per areole and 3–5(6) cm long. Areoles are 2–4 cm apart. Flowers have scarlet-reddish tepals, stamens with yellow anthers and scarlet-pink filaments, and pistil with white style and green stigma. Fruits are red.

Opuntia elatior was introduced in different countries and it became an important invasive weed in South and Southeast Asia and Australia. Later, these populations were eradicated or reduced to non-pest level by means of biological agents (Singh, 2004Singh, S. P. 2004. Some success stories in classical biological control of agricultural pests in India. Asia-Pacific Association of Agricultural Research Institutions (FAO Regional Office for Asia and the Pacific), Bangkok. ; Lloyd & Reeves, 2014Lloyd, S. & Reeves, A. 2014. Situation statement on opuntioid cacti (Austrocylindropuntia spp., Cylindropuntia spp. and Opuntia spp.) in Western Australia. Department of Agriculture and Food (Goverment of Western Australia), Perth. ).

All observed specimens have a vigorous appearance, unlike the widely spread neighbor O. maxima Mill., whose populations are in decline due to a cochineal attack.

Opuntia leucotricha DC. (Fig. 3F) (Cactaceae).

New to the north of Catalonia.

Barcelona, el Baix Llobregat: Gavà, C-245 road, by the sideway of the road crossing the roundabout, six adult specimens up to 1.8 m tall, set apart few meters each other, with an early stage of plant recruitment in some of them, DF162620, 6 m, 22.XII.2016, H. Alvarez & C. Gómez-Bellver (no voucher available). El Barcelonès: Barcelona, Turó de la Rovira, three young plants on gravelly and sandy slope, ca. 10 m apart, DF301855, 212 m, 11.II.2018, C. Gómez-Bellver & N. Marqués (no voucher available). Girona, l’Alt Empordà: Castelló d’Empúries, slope between the path to the camp site and the road C-260, near Mas Barceló, two young plants set apart ca. 5–7 m, EG069777, 7 m, 26.X.2017, P. Farelo, C. Gómez-Bellver & N. Ibáñez (no voucher available); Palau-Saverdera, in abandoned crops and wastelands, close to some houses, some individuals scattered on an area of about two hectares, with some other non-native plants, mainly Agave americana L. subsp. americana, Opuntia maxima Mill., O. engelmannii Salm-Dyck ex Engelm. ssp. lindheimeri (Engelm.) U. Guzmán & Mandujano var. linguiformis (Griffiths) B. D. Parfitt & Pinkava and Senecio angulatus L. f., EG123843, ca. 140 m, 10.XII.2017, J. López-Pujol (no voucher available). Tarragona, el Baix Camp: l’Aleixar, Mas del Cobrador, several specimens (including some adult ones) at the edge of a trail, growing together with other Opuntia taxa and Agave americana L. subsp. americana, CF355637, 290 m, 10.X.2014, J. López-Pujol (no voucher available); l’Ametlla de Mar, between cala Vidre and Cala Forn, 8 m, 01.III.2014, N. Girbau & L. Sáez (no voucher available); Cambrils, riera d’Alforja, CF355500, 43 m, 19.VII.2016, C. Gómez-Bellver, J. López-Pujol & N. Nualart (no voucher available); Mont-roig del Camp, riera de Riudecanyes, on the trail parallel to the dry river bed, a very large individual (about 2 m) and some small ones, CF307520, 98 m, 21.VII.2014, J. López-Pujol (no voucher available). El Baix Penedès: Bellvei, by the roadside (road N-340), near habitation, a large individual and some small ones, growing with other non-native plants including Opuntia monacantha Haw., and ×Gasteraloe beguinii (Radl) Guillaumin, CF808661, 95 m, 23.XII.2017, J. López-Pujol (no voucher available); el Vendrell, by the roadside (road N-340), next to the junction with road C-31, a single mature individual, CF777633, 62 m, 12.IX.2014, J. López-Pujol (no voucher available).

This cactus is endemic to the center of Mexico (Bravo, 1978Bravo, H. 1978. Las cactáceas de México 1. Universidad Nacional Autónoma de México, México D. F.; Anderson, 2001Anderson, E. F. 2001. The cactus family. Timber Press, Portland.). It was first reported for Catalonia by Sanz-Elorza et al. (2004bSanz-Elorza, M., Dana, E. D. & Sobrino, E. 2004b. Sobre la presencia de cactáceas naturalizadas en la costa meridional de Cataluña. Anales del Jardín Botánico de Madrid 61: 27–33. https://doi.org/10.3989/ajbm.2004.v61.i1.63) for the Tarragona Province, and by Pyke (2008Pyke, S. 2008. Contribución al conocimiento de la flora alóctona catalana. Collectanea Botanica 27: 95–104. https://doi.org/10.3989/collectbot.2008.v27.8 ) for the Barcelona Province, both as O. huajuapensis Bravo—also a Central Mexican cactus, but that grows further to the south (Arias et al., 2012Arias, S., Gama, S., Vázquez, B. & Guzmán, L. U. 2012. Flora del Valle de Tehuacán-Cuicatlán. Fascículo 95, Cactaceae. Instituto de Biología (Universidad Nacional Autónoma de México), México D. F.).

Opuntia leucotricha has whitish spines borning on the lower parts of the areoles; in contrast, O. huajuapensis has yellow spines awl-like, ascending to bent backward (Anderson, 2001Anderson, E. F. 2001. The cactus family. Timber Press, Portland.). Samuel Pyke told us recently that the plant he cited (Pyke, 2008Pyke, S. 2008. Contribución al conocimiento de la flora alóctona catalana. Collectanea Botanica 27: 95–104. https://doi.org/10.3989/collectbot.2008.v27.8 ) is actually referable to O. leucotricha. All the specimens we saw in Catalonia always displayed seedless fruits smaller in size than normal, as occurs in the former reports. The same results were observed for some prickly cactus under artificially induced parthenocarpy (Mejía & Cantwell, 2003Mejía, A. & Cantwell, M. 2003. Prickly pear fruit development and quality in relation to gibberellic acid applications to intact and emasculated flower buds. Journal of the Professional Association for Cactus Development 5: 72–85.). We consider that the lack of seeds—and the existence of some other fuzzy characters that could lead us to misunderstand the identity of the species—can be attributed either to hybridization or to successive generations of clonal growth. This process could have occurred spontaneously—not very common in this group (Lenzi & Orth, 2012Lenzi, M. & Orth, A. I. 2012. Mixed reproduction systems in Opuntia monacantha (Cactaceae) in Southern Brazil. Brazilian Journal of Botany 35: 49–58. https://dx.doi.org/10.1590/S0100-84042012000100006)—or as a product of selection by growers.

Figure 3. (A), Haworthiopsis attenuata, l’Ametlla de Mar; (B), translocated specimen of H. attenuata; (C), Leucaena leucocephala, Roda de Berà; (D), Lobelia laxiflora subsp. angustifolia, Barcelona; (E), Opuntia elatior, Esplugues de Llobregat; (F), Opuntia leucotricha, Gavà (photographs A, B, D–F: C. Gómez-Bellver; C: J. López-Pujol). [View full size] [Descargar tamaño completo]

Parthenocissus tricuspidata (Siebold & Zucc.) Planch. (Fig. 4A) (Vitaceae).

Casual, naturalized locally. Second record for Catalonia.

Barcelona, el Garraf: Garraf, on a rocky wall next to the stairs that lead down to the Puerto de Garraf Avenue, several plants, accompanied by Kalanchoe ×houghtonii D. B. Ward and Anredera cordifolia (Ten.) Steenis, DF080673, 11 m, 29.IX.2016, H. Álvarez & C. Gómez-Bellver (BC 955827, BCN 133401). Girona, el Baix Empordà: Palafrugell, beach of Tamariu, with Pittosporum tobira (Thunb.) W. T. Aiton, a dense group in the rear slope of the beach, covering an area of ca. 12–15 m² that reaches the sand, EG171405, 3 m, 18.VIII.2016, C. Gómez-Bellver & N. Marqués (no voucher available).

One of the three main Parthenocissus species used as ornamental for the covering of walls and fences. While two American species—P. inserta (A. Kern.) Fritsch and P. quinquefolia (L.) Planch—have palmately compound leaves, those of the Asian P. tricuspidata are simple, palmately three-lobed. All plants display numerous tendrils that allow them to grasp and climb vertical surfaces.

Parthenocissus tricuspidata has been reported for many central and southeast European countries (DAISIE, 2017DAISIE [Delivering Alien Invasive Species Inventories for Europe] 2018. Retrieved December 20, 2017, from http://www.europe-aliens.org; GBIF, 2017bGBIF [Global Biodiversity Information Facility] 2017b. Parthenocissus tricuspidata (Siebold & Zucc.) Planch. Retrieved January 9, 2018, from https://www.gbif.org/species/3039209. https://doi.org/10.15468/dl.7jezqn ). In Catalonia, it has only been reported from Barcelona Province (Casasayas, 1989Casasayas, T. 1989. La flora al·lòctona de Catalunya. Catàleg raonat de les plantes vasculars exòtiques que creixen sense cultiu al NE de la Península Ibèrica. PhD Thesis, Universitat de Barcelona, Barcelona.). Although P. tricuspidata probably does not have the same invasive capacity as the aforementioned congeners, its future spread in the territory is quite plausible.

Pennisetum flaccidum Griseb. (Fig. 4B) (Poaceae).

New to the Iberian Peninsula.

Barcelona, el Baix Llobregat: el Papiol, riera de Rubí, a compact group of plants accompanied by other neophytes, covering an area of ca. 2 m² with numerous reproductive stems, at the end of flowering, in nitrophilous grasslands in the riverbank next to some roads crossing an industrial facility, DF161877, 27 m, 23.IX.2016, H. Álvarez (BC 990386, BCN 134532, BCN 134533).

Perennial grass native to Central Asia, with tough spreading rhizomes, resistant to frost and dryness, which grows from 800 to 5000 m. It is used as a forage grass, for recovery or protection of soils in degraded areas, and also as ornamental plant (Chen & Phillips, 2006Chen, S. & Phillips, S. M. 2006. Pennisetum Richard. In: Wu, Z. Y. & Raven, P. H. (Eds.), Flora of China 22. Poaceae. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 548–552.; Szczesniak, 2011Szczesniak, E. 2011. Pennisetum flaccidum (Cenchrus flaccidus) (Poaceae) – new anthropophyte in flora of Poland. Fragmenta Floristica et Geobotanica Polonica 18: 295–300. ; Verloove, 2017Verloove, F. 2017 Manual of the alien plants of Belgium. Pennisetum flaccidum and Solidago gigantea. Botanic Garden of Meise, Belgium. Retrieved December, 2017, from http://alienplantsbelgium.be).

It has been reported for Europe in (1) Belgium (Natuurpunt, 2017Natuurpunt 2017. Slank lampenpoetsergras - Pennisetum flaccidum Griseb. Retrieved November 18, 2017, from https://waarnemingen.be/soort/info/125359 ; Verloove, 2017Verloove, F. 2017 Manual of the alien plants of Belgium. Pennisetum flaccidum and Solidago gigantea. Botanic Garden of Meise, Belgium. Retrieved December, 2017, from http://alienplantsbelgium.be), (2) the Netherlands, without specific location and a limited distribution in nature that makes it amenable to eradication (Matthews et al., 2014Matthews, J., Beringen, R., Creemers, R. et al. 2014. Horizonscanning for new invasive non-native species in the Netherlands. Department of Environmental Science (Institute for Water and Wetland Research, Faculty of Science, Radboud University), Nijmegen. ), (3) Germany, as P. centrasiaticum Tzvelev (Greuter & Raab-Straube, 2009Greuter, W. & Raab-Straube, E. von (Eds.) 2009. Euro+Med Notulae, 4 [Notulae ad floram euro-mediterraneam pertinentes 26]. Willdenowia 39: 327–333. https://doi.org/10.3372/wi.39.39210) but confirmed by Verloove (2017Verloove, F. 2017 Manual of the alien plants of Belgium. Pennisetum flaccidum and Solidago gigantea. Botanic Garden of Meise, Belgium. Retrieved December, 2017, from http://alienplantsbelgium.be) as P. flaccidum, and (4) Poland (Szczesniak, 2011Szczesniak, E. 2011. Pennisetum flaccidum (Cenchrus flaccidus) (Poaceae) – new anthropophyte in flora of Poland. Fragmenta Floristica et Geobotanica Polonica 18: 295–300. ). Some agricultural experiments performed in the United States evaluated the forage capacity of this grass, but we have only found a clear reference to this plant as escaped from cultivation in Texas (Barkworth et al., 2007Barkworth, E., Anderton, L. K., Capels, K. M., Long, S. & Piep, M. B. (Eds.) 2007. Manual of grasses for North America. Utah State University Press of Colorado, Logan. https://doi.org/10.2307/j.ctt4cgkq1). In case of new introductions, it could become invasive.

Podranea ricasoliana (Tanfani) Sprague (Fig. 4C) (Bignoniaceae).

Second record for Catalonia.

Barcelona, el Barcelonès: Esplugues de Llobregat, la Miranda neighborhood, a population in blossom of ca. 40 m², thriving on the mountain slope, towards the end of a residential area, DF239822, 227 m, 12.I.2018, C. Gómez-Bellver & H. Álvarez (BC 990553, BCN 143488). Girona, el Baix Empordà: Torroella de Montgrí, in Pedrosa’s little bay, 2 km towards the south of Tamariu, on a rocky slope, in blossom, with Vitis riparia Michx., EG171395, 4 m, 18.VII.2016, C. Gómez-Bellver & N. Marqués (no voucher available).

Ornamental creeper, with South Africa generally accepted as native area, although some South African authors think that it was introduced by slave merchants (Lee et al., 2016Lee, K. L., Singhurst, J. R. & Holmes, W. C. 2016. Podranea ricasoliana (Bignoniaceae) adventive in Texas. Phytoneuron 40: 1–3. ).

In Catalonia it has only been reported from the northeast, from the Baix Empordà county, by Mallol & Maynés (2008Mallol, A. & Maynés, J. 2008. Nous xenòfits al Baix Empordà (Catalunya). Acta Botanica Barcinonensia 51: 59–77.). The vigorous growth observed in Barcelona’s population makes us believe that this plant could behave as a locally invasive species if more propagule pressure takes place in the future.

Rudbeckia hirta L. (Fig. 4D) (Asteraceae).

Second record for Catalonia.

Barcelona, el Barcelonès: Barcelona, Besòs River Park, la Trinitat Vella, near Baró de Viver, right river bank, a few individuals scattered in a nitrophilous grassland, accompanied mainly by Anacyclus valentinus L., Bromus catharticus Vahl, Sonchus oleraceus L. and Trifolium repens L. as well as ornamental plants like Eschscholzia californica Cham. and Linum grandiflorum Desf., along ca. 700 m, presumably as a result of a former local city council urban action, DF336884, 13 m, 05.V.2017, C. Gómez-Bellver (BC 990558, BCN 143186); Barcelona, Can Tunis, in some road-banks of the Avda. Zona Franca in the junction with the harbor, as a cultivated plant [originally cultivated as an ornamental plant, now it is persisting from cultivation, C. Gómez-Bellver et al., pers. obs., May 2018], DF2978, 5 m, 07.VII.2015, S. Pyke (BC 998211).

This ornamental coneflower is native to North America. Blade leaves are elliptic, lanceolate, or ovate (not lobed), and the center disc brown-purple to dark brown (Urbatsch & Cox, 2005Urbatsch, L. E. & Cox, P. B. 2005. Rudbeckia. In: Flora of North America Editorial Committee (Eds.), Flora of North America North of Mexico 21. Oxford University Press, New York & Oxford: 45–52.).

We are aware of the active cultivation of this species in gardens, road banks and artificial slopes in Catalonia, mainly in the city of Barcelona and nearby villages. We provide here the report of a population probably persistent of cultivated origin in the Besòs River Park.

It was previously reported for Catalonia by Viñas (1993Viñas, X. 1993. Flora i vegetació de l’Alta Garrotxa. PhD Thesis, Universitat de Girona, Girona.) from the province of Girona. Another alien congeneric species reported for Catalonia by Bolòs (1998Bolòs, O. de 1998. Atlas Corològic. Volum Extraordinari: Primera compilació general 1 & 2. Secció de Ciències Biològiques (Institut d’Estudis Catalans), Barcelona.), R. laciniata L., differs by the basal and midstem leaves being usually 1–2 pinnatifid or pinnately lobed, and the yellowish green disc florets.

Senecio crassissimus Humbert (Fig. 4E) (Asteraceae).

New to Europe.

Tarragona, el Tarragonès: Tarragona, l’Escorpí neighborhood, in a margin of an Aleppo pine forest, two patches separated by a few dozen metres, near habitation, CF590559, ca. 60 m, 11.II.2017, J. López-Pujol (BC 958002).

The vertical leaf senecio is a dwarf shrub (up to 80 cm) with succulent stems native to Madagascar (Rowley, 2002Rowley, G. D. 2002. Senecio. In: Eggli, U. (Ed.), Illustrated handbook of succulent plants: Dicotyledons. Springer-Verlag, Berlin: 29–43.). It is easily distinguishable by its leaves, ovate, laterally compressed, glaucous green with vivid purple margins. Inflorescences are loose corymbs that carry over 30 bright yellow daisy-like heads.

Despite being widely used as an ornamental, we are not aware of any occurrence as escaped or naturalized apart from our observation. The individuals of S. crassissimus from Tarragona are likely to have escaped from the nearby private gardens, as we also found other common escapes from cultivation, such as Aeonium arboreum Webb & Berthel., Crassula muticava Lem. and C. ovata (Mill.) Druce.

Tradescantia sillamontana Matuda (Fig. 4F) (Commelinaceae).

New to Catalonia.

Barcelona, el Barcelonès: Barcelona, Sants District, on a channel in the roof of 47 Blanco street, accompanied by Kalanchoe ×houghtonii, DF275808, 27 m, 07.XI.2017, J. López-Pujol (BC-HV-967107).

Native to northeastern Mexico (Alanís-Flores et al., 2011Alanís-Flores, G. J., Alvarado-Vázquez, M. A., Ramírez-Freire, L., Foroughbakhch-Pornavab, R. & Velazco-Macías, C. G. 2011. Flora endémica de Nuevo León, México y estados colindantes. Journal of the Botanical Research Institute of Texas 5: 275–298.), it is a small perennial herbaceous plant with densely hairy stems and leaves that give the plant a recognizable velvety appearance, with terminal more or less intense pink flowers. As with many other ornamental plants, its vegetative propagation by means of cuttings is easy.

It has been reported for the Iberian Peninsula in the city of Valencia (Talavera et al., 2010Talavera, S., Gallego, M. J. & Herrero, A. 2010. Commelinaceae In: Castroviejo, S., Talavera, S., Gallego, M. J., Romero Zarco, C. & Herrero, A. (Eds.), Flora iberica 17. Real Jardín Botánico (CSIC), Madrid: 118–121.). Regarding the rest of Europe, there is only one specific report from southern Italy (Stinca et al., 2012Stinca, A., D’Auria, G. & Motti, R. 2012. Integrazioni alla flora vascolare aliena della Campania (Sud Italia). Informatore Botanico Italiano 44: 287–293. ) as casual. In the Iberian Peninsula, three species within this genus are mentioned as subspontaneous: T. pallida (Rose) D. R. Hunt and T. zebrina Heynh. in Andalusia and the Valencian Community, and T. virginiana L. in the Valencian Community (Talavera et al., 2010Talavera, S., Gallego, M. J. & Herrero, A. 2010. Commelinaceae In: Castroviejo, S., Talavera, S., Gallego, M. J., Romero Zarco, C. & Herrero, A. (Eds.), Flora iberica 17. Real Jardín Botánico (CSIC), Madrid: 118–121.).

Figure 4. (A), Parthenocissus tricuspidata, Palafrugell; (B), Pennisetum flaccidum, el Papiol; (C), Podranea ricasoliana, Esplugues de Llobregat; (D), Rudbeckia hirta, Barcelona; (E), Senecio crassissimus, Tarragona; (F), Tradescantia sillamontana, Barcelona (photographs A, C, D: C. Gómez-Bellver; B: H. Álvarez; E, F: J. López-Pujol). [View full size] [Descargar tamaño completo]

ACKNOWLEDGMENTSTop

The authors wish to express their gratitude to S. Pyke from the Botanic Garden of Barcelona for his valuable comments, to P. Verloove & A. Guiggi for their help in identifying Opuntia elatior, to Dr. L. Scheinvar from the National Autonomous University of Mexico for her remarks on Opuntia leucotricha, to P. Aymerich for providing the precise location of his report of Haworthiopsis attenuata, as well as to J. Altimira for providing the report of Clerodendrum bungei Steud. Finally, we thank the two anonymous reviewers for their careful reading and their many insightful comments and suggestions. This study received financial support from the “Proyecto Intramural Especial, PIE” (grant no. 201630I024) from the CSIC.

REFERENCESTop