In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Alien species, floristic data, Italy, nomenclature

The text for the new records should be submitted electronically to Lorenzo Lastrucci (lorenzo.lastrucci@unifi.it). The corresponding specimen along with its scan or photograph has to be sent to FI Herbarium: Museo di Storia Naturale (Botanica), Sistema Museale di Ateneo, Via G. La Pira 4, 50121 Firenze (Italy). Those texts concerning nomenclatural novelties (typifications only for accepted names), status changes, exclusions, and confirmations should be submitted electronically to Gabriele Galasso (gabriele.galasso@comune.milano.it). Each text should be within 1,000 characters (spaces included).

Albizia julibrissin Durazz. (Fabaceae)

+ (CAS) MAR: Pesaro (Pesaro e Urbino), Via S. Pertini ai margini del Ponte Giovanni XXIII (WGS84: 43.900625N, 12.875721E), margine stradale erboso, ca. 10 m, 18 July 2021, L. Gubellini (FI, PESA). – Casual alien species new for the flora of Marche.

A single individual has been observed, flowering in a roadside verge.

L. Gubellini, N. Hofmann

Aubrieta deltoidea (L.) DC. (Brassicaceae)

+ (CAS) PIE: Salbertrand (Torino), fraz. San Romano, presso il Camping Gran Bosco (WGS84: 45.062215N, 6.867815E), interstizi tra un muretto e la strada asfaltata in prossimità di una aiuola coltivata, 1023 m, 3 April 2021, M. Probo, M. Lonati (FI). – Casual alien species new for the flora of Piemonte.

Some individuals occur spontaneously near a private garden where the species is cultivated as ornamental.

M. Probo, M. Lonati

Bothriochloa pertusa (L.) A.Camus (Poaceae)

+ (NAT) ITALIA (LIG): Sestri Levante (Genova), ZSC “IT1333308 Punta Manara”, loc. Ginestra (WGS84: 44.2617N, 9.4158E), bordo del sentiero, a margine di oliveto in coltura, ca. 110 m, SE, 23 July 2020, leg. D. Dagnino, C. Turcato, det. E. Banfi (FI, GE No. 4891, MSNM Nos. 50854, 50855). – Naturalized alien species new for the flora of Italy (Liguria).

This species is similar to Bothriochloa insculpta (Hochst. ex A.Rich.) A.Camus, represented in Italy by subsp. panormitana (Parl.) Giardina & Raimondo, from which is distinguished by the number and color of the racemes (3–8 brown-straw vs of 10–15 blackish) and by the lower glume bearing long woolly whitish hairs grouped in the distal half (Vega 2000). It is native to warm temperate and tropical Old World from where it has been introduced in Mesomerica, South America (Colombia) and southern North America (Alabama, Florida, Louisiana, Mississippi), while in Europe is reported from Sweden and considered doubtfully alien in Greece (Valdés and Scholz 2009+; POWO 2019+). It prefers uncultivated and grassy places, but at present it is impossible to evaluate the potential aggressiveness of the species.

E. Banfi, D. Dagnino, C. Turcato, G. Galasso

Brugmansia aurea Lagerh. (Solanaceae)

+ (CAS) CAM: San Giorgio a Cremano (Napoli), al confine con Napoli, Via Cupa Rubinacci (WGS84: 40.834822N, 14.328418E), bordo strada, 32 m, 7 April 2021, leg. R. Motti, det. R. Motti, A. Cozzolino, A. Stinca (FI, PORUN-Motti); ibidem, 9 July 2021, A. Stinca (PORUN-Stinca). – Casual alien species new for the flora of Campania.

In Italy, two species belonging to the South American genus Brugmansia Pers. have been recorded: B. aurea in Calabria (Laface et al. 2020) and B. suaveolens (Humb. & Bonpl. ex Willd.) Sweet in Campania (Stinca 2020). The new finding refers to an individual probably originated vegetatively from plants cultivated nearby.

R. Motti, A. Cozzolino, A. Stinca

Centaurea diluta Aiton (Asteraceae)

+ (NAT) BAS: Matera (Matera), confine tra Puglia e Basilicata, in prossimità del vulcanello di Gravina di Puglia (WGS84: 40.700063N, 16.428955E), incolti in pros­simità di colture di orzo, 208 m, 3 June 2021, M. Terzi, F.S. D’Amico (FI). – Naturalized alien species new for the flora of Basilicata.

A population of Centaurea diluta was found on clayey soils along the edge of a path close to the border between Basilicata and Puglia.

M. Terzi, F.S. D’Amico

Chasmanthe bicolor (Gasp.) N.E.Br. (Iridaceae)

+ (NAT) SAR: La Maddalena (Sassari), Parco Nazionale dell’Arcipelago di La Maddalena, Isola La Maddalena (WGS84: 41.236234N, 9.410872E), in prossimità delle strade e nelle radure della macchia, 67 m, 27 March 2021, G. Brundu, V. Lozano, V. Lazzeri (FI, Herb. Uniss Agraria). – Naturalized alien species new for the flora of Sardegna.

Chasmanthe bicolor is a perennial herb native to the Western Cape Province in South Africa (de Vos 1985; Duncan 2001).

V. Lozano, G. Brundu, V. Lazzeri

Cupressus sempervirens L. (Cupressaceae)

+ (NAT) CAL: Reggio Calabria (Reggio Calabria), Via V. Florio, nei pressi del porto (WGS84: 38.119704N, 15.649376E), dentro il tronco cavo di una pianta di Melia azedarach, 23 m, 13 April 2021, leg. G. Spampinato, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (FI, REGGIO); ibidem, Piani di San Nicola, fraz. Ortì (WGS84: 38.151801N, 15.695425E), bordo strada, 559 m, 18 July 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (REGGIO); ibidem, Diminniti di Sambatello, nei pressi del cimitero (WGS84: 38.174036N, 15.702576E), terreno abbandonato, 425 m, 18 July 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (REGGIO); Condofuri (Reggio Calabria), fraz. Straci (WGS84: 37.924573N, 15.844811E), nel bosco e a bordo strada, 33 m, 11 May 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (REGGIO); ibidem, Trombia (WGS84: 37.937525N, 15.866372E), eucalipteto e bordo strada, 106 m, 18 July 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (REGGIO); ibidem, fraz. Pietra (WGS84: 37.947734N, 15.865268E), pineta e bordo strada, 151 m, 18 July 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (REGGIO); Montebello Jonico (Reggio Calabria), Canale (WGS84: 37.958997N, 15.695899E), eucalipteto e bordo strada, 148 m, 18 July 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (REGGIO). – Naturalized alien species new for the flora of Calabria.

Cupressus sempervirens reproduces easily by seed and at most of the reported localities, the species has formed small populations, with some mature and reproductive adult individuals.

G. Spampinato, V.L.A. Laface, C.M. Musarella

Cuscuta campestris Yunck. (Convolvulaceae)

+ (NAT) LIG. – Status change from casual to naturalized alien for the flora of Liguria.

We found several populations of Cuscuta campestris along the Magra Valley (La Spezia), showing a high number of individuals growing on different host plants (e.g., Convolvulus arvensis L., Euphorbia maculata L., Xanthium italicum Moretti, etc.) in ruderal environments linked to the riverside terraces or the anthropized areas of the Magra plain. We collected several herbarium specimens of these populations, currently housed in GE.

D. Dagnino, I. Briozzo, C. Turcato

Cyrtomium falcatum (L.f.) C.Presl (Dryopteridaceae)

+ (CAS) SAR: Cagliari (Cagliari), Via Vittorio Veneto (WGS84: 39.225230N, 9.105523E), fessure di un muro di contenimento in pietra calcarea, 41 m, 25 February 2021, L. Rosati, M. Marignani (FI). – Casual alien species new for the flora of Sardegna.

We observed, growing on a wall colonized also by Adiantum capillus-veneris L. and Cymbalaria muralis G.Gaertn., B.Mey. & Scherb. subsp. muralis, a single individual.

L. Rosati, M. Marignani

Delosperma cooperi (Hook.f.) L.Bolus (Aizoaceae)

+ (CAS) ABR: Teramo (Teramo), Via Conte Contin (WGS84: 42.656388N, 13.696388E), bordo stradale, ca. 254 m, 15 May 2021, N. Olivieri (FI). – Casual alien species new for the flora of Abruzzo.

Some individuals of the species are settled on the concrete roadside, sometimes covered with moss, together with Sedum dasyphyllum L. subsp. dasyphyllum and sporadically S. palmeri S.Watson, in an area not subject to foot traffic.

N. Olivieri

Dimorphotheca fruticosa (L.) Less. (Asteraceae)

+ (CAS) SAR: Carloforte (Sud Sardegna), Isola di San Pietro, loc. Nasca (WGS84: 39.157107N, 8.264874E), bordo strada, dietro ad un muretto a secco nella macchia, 96 m, 6 March 2021, leg. L. Rosati, M. Marignani, G. Cocco, S. Bardi, det. L. Rosati (HLUC); ibidem, loc. Tacca Rossa (WGS84: 39.161726N, 8.302175E), scarpata stradale, 48 m, 7 March 2021, leg. L. Rosati, M. Marignani, G. Cocco, S. Bardi, det. L. Rosati (FI). – Casual alien species new for the flora of Sardegna.

Some flowering individuals were observed growing in garrigues dominated by Cistus monspeliensis L.

G. Sotgiu Cocco, L. Rosati, S. Bardi, M. Marignani

Dracaena draco (L.) L. subsp. draco (Asparagaceae)

+ (CAS) SAR: Cagliari (Cagliari), Viale Buon Cammino (WGS84: 39.222723N, 9.115725E), epifita su Celtis australis, 94 m, 15 April 2021, A. Lallai, G. Bacchetta, L. Podda (FI, CAG). – Casual alien species new for the flora of Sardegna.

This species is native to Macaronesia and Morocco, where it grows on slopes in association with other xerophilous taxa (Almeida Pérez 2003). The juvenile specimen found in Sardegna grows epiphytic in the bifurcation of the branches on a decayed Celtis australis L. subsp. australis, approximately 20 m away from a mature individual.

A. Lallai, G. Bacchetta, L. Podda

Erigeron philadelphicus L. (Asteraceae)

+ (CAS) EMR: Ferrara (Ferrara), Via Dosso Dossi (WGS84: 44.842018N, 11.619414E), vegetazione sinantropica ruderale, 10 m, 7 May 2021, leg. M. Curuzzi, G. Mei, det. G. Mei (FI, Herb. G. Mei). – Casual alien species new for the flora of Emilia-Romagna.

G. Mei, M. Curuzzi

Euthamia graminifolia (L.) Nutt. (Asteraceae)

– ITALIA (PIE). – Alien species to be excluded from the flora of Italy (Piemonte).

The report of Euthamia graminifolia in Piemonte (Soldano and Sella 1988) is to be referred to E. lanceolata (L.) G.L.Nesom (see below).

G. Galasso, A. Soldano

Euthamia lanceolata (L.) G.L.Nesom (Asteraceae)

+ (NAT) ITALIA (PIE): Castelletto Cervo (Biella), baraggia sul lato W della strada provinciale verso San Giacomo di Masserano (WGS84: 45.53388N, 8.24138E), brughiera, 229 m, no exp., 20 August 1990, A. Soldano 8801 (Herb. A. Soldano sub. E. graminifolia); ibidem, baraggia lungo la strada SP315 San Giacomo–Buronzo (WGS84: 45.536587N, 8.240707E ± 10 m), brughiera, ca. 221 m, no exp., 12 September 2009, G. Galasso (MSNM Nos. 43684, 43685, 43686 sub. E. graminifolia); Masserano (Biella), lato W della Baraggia delle Quattro Madame (WGS84: 45.54800N, 8.25416E), brughiera, 235 m, no exp., 4 September 1993, A. Soldano 9436 (Herb. A. Soldano sub. E. graminifolia). – Naturalized alien species new for the flora of Italy (Piemonte).

According to the recent revision of the genus Euthamia (Nesom 2021a, b), our specimens previously attributed to E. graminifolia (L.) Nutt. belong to E. lanceolata. Although the height of the involucres (4.0–4.2 mm) is more or less intermediate between the two species (3.6–4.2 mm in E. lanceolata vs 4.0–5.0 mm in E. graminifolia), stem and leaf surfaces are clearly hirtellous (vs glabrous).

G. Galasso, A. Soldano

Gazania rigens (L.) Gaertn. (Asteraceae)

+ (NAT) SAR. – Status change from casual to naturalized alien for the flora of Sardegna.

Gazania rigens was detected as naturalized in the sand dunes of Torre dei Corsari (Arbus, Sud Sardegna) and in the small peninsula of Capo Coda Cavallo (San Teodoro, Sassari). These self-sustaining populations are fast-spreading, after a recent introduction as ornamentals in gardens.

M. Fois, A. Cuena-Lombraña, G. Brundu

Honorius boucheanus (Kunth) Holub (Asparagaceae)

+ (CAS) LOM: Mantova (Mantova), Corte Cherubine, Via Legnago 17 (WGS84: 45.165820N, 10.832494E), all’ombra di un filare d’alberi, 19 m, no exp., 24 April 2021, leg. E. Guidotti, P. Lanfredini, M. Marchini, det. E. Guidotti, M. Pallanza, S. Orsenigo (FI). – Casual alien species new for the flora of Lombardia.

E. Guidotti, P. Lanfredini, M. Marchini, M. Pallanza

Hyacinthoides non-scripta (L.) Chouard ex Rothm. (Asparagaceae)

+ (CAS) UMB: Gualdo Tadino (Perugia), Appennino di Gualdo Tadino, Valle del Fònno, versante SW (WGS84: 43.226585N, 12.815555E), margine erboso delimitato da rocce calcaree rivestite da una fitta lecceta, 790 m, 2 April 2021, M. Loreti, P. Salerno (FI). – Casual alien species new for the flora of Umbria.

Only a group of five plants was found in an impervious Appennine area with a high level of wilderness, included into the ZSC “IT5210014 Monti Maggio-Nero (sommità)”.

M. Loreti, P. Salerno

Ipheion uniflorum (Lindl.) Raf. (Amaryllidaceae)

+ (CAS) LOM: Concorezzo (Monza e Brianza), lungo Via G. Mazzini (WGS84: 45.585790N, 9.341909E), incolto, 172 m, 2 April 2021, G. Patera (FI). – Casual alien species new for the flora of Lombardia.

A few individuals of this species originated from seeds produced by some adults growing in a nearby garden.

G. Patera

Koelreuteria paniculata Laxm. (Sapindaceae)

+ (NAT) VDA: Arnad (Aosta), presso la Chiesa di San Martino, dietro il giardino pubblico, lungo l’argine del Torrente d’Arnad (WGS84: 45.6446009N, 7.7206899E), greto e argini del torrente, molti esemplari in fruttificazione, 361 m, 2 August 2021, A. Selvaggi (FI); ibidem, più in basso, scendendo lungo il Torrente d’Arnad, nel greto (WGS84: 45.64437562N, 7.71966776E), greto fluviale, 358 m, 2 August 2021, A. Selvaggi (AO). – Naturalized alien species new for the flora of Valle d’Aosta.

The naturalized population extends more than 100 metres along the river Torrente d’Arnad and includes numerous individuals at different stages of growth. All the individuals originate from few cultivated plants grown in the public garden situated behind the San Martino church.

A. Selvaggi, P. Ferraris

Melinis repens (Willd.) Zizka subsp. repens (Poaceae)

+ (INV) SAR. – Status change from naturalized to invasive alien for the flora of Italy (Sardegna).

Since the first report in 2018 (Galasso et al. 2019a) we have observed a rapid expansion of this taxon, which is spreading from roadsides of coastal areas to inland fields, to the extent that we believe it is becoming a problematic weed for the nearby crops.

G. Bacchetta, G. Calvia, L. Podda

Nassella tenuissima (Trin.) Barkworth (Poaceae)

+ (CAS) LOM: Costa Volpino (Bergamo), nei pressi della ex cava di gesso lungo il margine destro della strada di recente costruzione che sale alla fraz. Volpino (WGS84: 45.836317N, 10.102783E), margine stradale, 202 m, SE, 28 May 2021, leg. A. Federici, det. G. Galasso, E. Banfi (FI, MSNM No. 50996); Milano (Milano), passaggio pedonale parallelo a Via E. Fieramosca, presso la Residenza Arcimboldi, recinzione al di sopra della trincea della linea tramviaria (WGS84: 45.515361N, 9.214027E), fughe nella pavimentazione stradale a mattonelle, 134 m, no exp., 2 June 2021, G. Galasso (FI, MSNM Nos. 50984, 50985). – Casual alien species new for the flora of Lombardia.

In both cases, the collected specimens were growing very far from the mother plants.

G. Galasso, E. Banfi, A. Federici

Nelumbo nucifera Gaertn. (Nelumbonaceae)

+ (NAT) TOS. – Status change from casual to naturalized alien for the flora of Toscana.

The first records of this species for Toscana date back to Montelucci (1964, 1970) from Massarosa (Lucca province), where it has been recorded again in 2017 (Peruzzi and Bedini 2021+). Here, new records from Parco di Fonte Santa (Bagno a Ripoli, Firenze, WGS84: 43.710670N, 11.372633E, 578 m, 29 July 2021, L. Lazzaro, L. Lastrucci, FI) and from Piazza delle Gondole in Pisa (WGS84: 43.716768N, 10.409048E, obs. B. Pierini, L. Peruzzi) are added. In these sites, the populations are in an evident naturalized status, with the presence of many flowers and fruits. We therefore propose the change of status for this species in Toscana from casual to naturalized.

L. Lazzaro, L. Lastrucci

+ (NAT) MAR: Potenza Picena (Macerata), c.da Castelletta, stagno artificiale (WGS84: 43.346644N, 13.657330E), stagno, 24 m, 10 July 2021, D. Fiacchini (FI). – Naturalized alien species new for the flora of Marche.

Nelumbo nucifera grows inside the artificial pond located less than 30 metres from the right bank of the Asola stream. The species occupies a total area of c. 1,500–2,000 m².

D. Fiacchini, L. Gubellini

Parasenegalia visco (Lorentz ex Griseb.) Seigler & Ebinger (Fabaceae)

– SAR. – Alien species to be excluded from the flora of Sardegna.

Parasenegalia visco was first reported by Podda et al. (2010) from Rio Santa Lucia in Capoterra (Cagliari) as a new casual alien species for Sardegna. Later, it was indicated by the same authors as a naturalized alien (Podda et al. 2012; Puddu et al. 2016). Field insights and a review of specimens in CAG have shown that these records are due to a misidentification of Paraserianthes lophantha (Willd.) I.C.Nielsen subsp. lophantha.

L. Podda, A. Lallai, G. Bacchetta

Parkinsonia aculeata L. (Fabaceae)

+ (INV) SAR. – Status change from casual to invasive alien for the flora of Sardegna.

Recently, rapid colonization from seeds in dense thickets have been observed in several areas from Cagliari to the road SS131 and to Santa Margherita (Pula, Cagliari), or wetlands near Cagliari such “Stagno di Santa Gilla”, and “Stagno di Molentargius” (Cagliari province).

G. Bacchetta, M. Fois, L. Podda

Passiflora caerulea L. (Passifloraceae)

+ (NAT) LAZ. – Status change from casual to naturalized alien for the flora of Lazio.

During the last four years, investigations revealed that this species is widespread in northern Lazio with well-established populations in the provinces of Viterbo (e.g., Viterbo, Montalto di Castro, Oriolo Romano) and Roma, where it also grows on the beaches of Lake Bracciano. These populations regularly produce fruits and propagate both vegetatively and by seed.

S. Magrini, S. Buono

Platanus hispanica Mill. ex Münchh. (Platanaceae)

+ (INV) ITALIA (LAZ). – Status change from naturalized to invasive alien for the flora of Italy (Lazio).

Recent investigations in the province of Roma revealed that this species has largely colonized the shores of the river Tiber and Aniene, all along the urban and suburban area and beyond, as well as other riparian habitats. From there, it is currently spreading also along roadsides and in archaeological sites (Celesti-Grapow and Ricotta 2020).

L. Celesti-Grapow

Platycladus orientalis (L.) Franco (Cupressaceae)

+ (NAT) VDA: Saint-Vincent (Aosta), sulla collina tra Cillian e Felliey (WGS84: 45.739636N, 7.663596E), un esemplare inselvatichito in fessura delle rupi di serpentino, 660 m, 26 May 2012, leg. M. Bovio, G.P. Mondino, det. G.P. Mondino (AO); Bard (Aosta), presso il sentiero che costeggia le rocce alla base del Forte di Bard (WGS84: 45.60614630N, 7.74672678E), fessure delle rocce “montonate”, 400 m, S, 27 July 2021, A. Selvaggi (FI); ibidem (WGS84: 45.6066190N, 7.7471075E), fessure delle rocce, 420 m, 2 August 2021, A. Selvaggi (AO). – Naturalized alien species confirmed for the flora of Valle d’Aosta.

Many individuals of this species have colonized the rock cracks at different points around the base of Forte di Bard; some of these plants are already fertile or ready to disperse the seeds. The presence of the species in Valle d’Aosta was previously annotated by Bovio (2014) as casual, but not by Galasso et al. (2018a). Other findings were recorded also in Collina di Châtillon (WGS84: 45.739636N, 7.663596E and 45.753752N, 7.615628E, 17 April 2019, obs. M. Bovio, C. Ganz, M. Broglio, G. Trompetto), Pont-Saint-Martin (WGS84: 45.598159N, 7.801948E, 1 May 2019, obs. M. Bovio), and between Plan de Brun and Perloz (WGS84: 45.606255N, 7.802994E, 21 May 2021, obs. M. Bovio, C. Ganz, O. Deval, G. Jacquemet).

A. Selvaggi, M. Bovio, G.P. Mondino

Populus ×canadensis Moench (Salicaceae)

+ (INV) ITALIA (LAZ). – Status change from naturalized to invasive alien for the flora of Italy (Lazio).

+ (INV) SAR. – Status change from casual to invasive alien for the flora of Sardegna.

Recent investigations in Lazio revealed that this nothospecies has largely spread in riparian habitats along the shores of the river Tevere and its affluents, in the urban and suburban area of Roma and beyond. It is also currently spreading in archaeological sites and on the top of buildings, particularly in roof gutters. Similarly, in Sardegna, it is spreading in suburban areas and in riparian sites from planted stands (e.g., along the river Tirso at Fordongianus, Oristano, WGS84: 39.997N, 8.807E, obs. G. Brundu).

G. Brundu, L. Celesti-Grapow

Pteris multifida Poir. (Pteridaceae)

+ (CAS) TOS: Pisa (Pisa), Via Roma 56 (WGS84: 43.719187N, 10.395475E), in tombino, 4 m, 10 June 2021, L. Pinzani (FI, Herb. L. Pinzani). – Casual alien species new for the flora of Toscana.

L. Pinzani

Quercus palustris Münchh. (Fagaceae)

+ (CAS) ITALIA (LOM): Milano (Milano), piazza d’Armi, tra Via delle Forze Armate, Via della Rovere e Via G. Mazzarino (WGS84: 45.464368N, 9.122097E), boscaglia umida, 123 m, no exp., 7 July 2021, leg. G. Galasso, det. G. Galasso, E. Banfi (FI, MSNM Nos. 51005, 51006, 51007, 51008); Besnate (Varese), stagno Lagozzetta (WGS84: 45.703333N, 8.744722E), spontaneizzata sulle rive boschive dell’area umida, 276 m, no exp., 18 July 2021, leg. M. Martignoni, det. G. Galasso, E. Banfi (FI, MSNM No. 51038). – Casual alien species new for the flora of Italy (Lombardia).

In Milano, some individuals of the species, identified according to Jensen (1997), grow in a former semi-natural military area, with temporary pools rich in particularly interesting species.

G. Galasso, E. Banfi, M. Martignoni, N. Pilon

Rhus typhina L. (Anacardiaceae)

+ (CAS) ABR: Bellante (Teramo), loc. Bellante Stazione, Via del Commercio (WGS84: 42.706944N, 13.852777E), vegetazione lungo il bordo stradale, ca. 98 m, 19 July 2021, N. Olivieri (FI). – Casual alien species new for the flora of Abruzzo.

Several young shrubby individuals occur in the record site, some of which bearing fruit, on both sides of a road.

N. Olivieri

Robinia neomexicana A.Gray (Fabaceae)

+ (CAS) MAR: Pietrarubbia (Pesaro e Urbino), lungo la strada SP1 (WGS84: 43.790709N, 12.361800E), siepi, ca. 715 m, 10 June 2021, L. Gubellini (FI, PESA); ibidem, 13 August 2021, L. Gubellini (FI, PESA). – Casual alien species new for the flora of Marche.

The species was identified according to Peabody (1984) and Isely and Peabody (1984).

L. Gubellini, N. Hofmann

Salvia hispanica L. (Lamiaceae)

+ (CAS) CAL: Cirò (Crotone), nei pressi dell’abitato, poco a N di Via Madonna delle Grazie (strada SP7) (WGS84: 39.382263N, 17.063990E), incolto, 290 m, 12 September 2019, G. De Fine (CLU). – Casual alien species new for the flora of Calabria.

N.G. Passalacqua, G. De Fine

Scirpus atrovirens Willd. subsp. hattorianus (Makino) Verloove & Lambinon (Cyperaceae)

+ (CAS) LAZ: Latina (Latina), fraz. Borgo Piave (WGS84: 41.486944N, 12.846667E), sponde di un piccolo pantano, suolo sabbioso e argilloso, 28 m, 5 July 1999, leg. F. Minutillo, det. L. Lastrucci, conf. F. Verloove (FI). – Casual alien subspecies new for the flora of Lazio.

The specimen was identified according to Whittemore and Schuyler (2002).

F. Minutillo, G. Tondi

Sedum rubrotinctum R.T.Clausen (Crassulaceae)

+ (CAS) MAR: Cupra Marittima (Ascoli Piceno), margine della strada SS16 Adriatica (WGS84: 43.0291619N, 13.8575740E), margine stradale, ca. 6 m, 3 August 2020, N. Olivieri (FI). – Casual alien species new for the flora of Marche.

This Mexican species, identified according to Groendijk-Wilders and Springate (2011) and Horwath (2014), was recently reported as a casual alien in Campania by Del Guacchio et al. (2020). In Cupra Marittima this culton has colonized the edge of the sidewalk in an area of limited extension within the town. The plant grows on a thin and not very developed substrate.

N. Olivieri

Semiarundinaria fastuosa (Lat.-Marl. ex Mitford) Makino (Poaceae)

+ (CAS) LOM: Bergamo (Bergamo), Parco Regionale dei Colli di Bergamo, inizio del sentiero di Via dei Vasi partendo da Via Castagneta, lato a valle (WGS84: 45.71567N, 9.65165E), ex ceduo di castagno in evoluzione verso un bosco misto di farina, carpino bianco e acero campestre, ca. 380 m, NE, 13 July 2021, E. Banfi (FI); ibidem, 24 July 2021, E. Banfi (MSNM Nos. 51032, 51033, 51034, 51035, 51036, 51037, 51352, 51353). – Casual alien species new for the flora of Lombardia.

Semiarundinaria fastuosa is a bamboo native to central-southern Japan, cultivated as ornamental in Italy and escaped in Piemonte (Galasso et al. 2019b), to whose report we refer for the diagnostic characters of the species. Other individuals have been observed in the semi-abandoned garden of a property in Via F. Cavagnis, about 1 km away, testifying to a previous historical use of the species in Bergamo.

E. Banfi, G. Galasso

Sesbania punicea (Cav.) Benth. (Fabaceae)

+ (INV) SAR. – Status change from naturalized to invasive alien for the flora of Sardegna.

The species is currently considered as naturalized, especially along freshwater courses (Galasso et al. 2018b). However, a large and spreading population has been observed along ‘Bau sa Teula’ (Villagrande Strisaili, Nuoro), where it is rapidly colonizing the coastal sector of the same river basin (Tortolì and Lotzorai, Nuoro). Accordingly, its status needs to be changed to invasive.

M. Fois, A. Cuena-Lombraña, G. Bacchetta

Sorbaria tomentosa (Lindl.) Rehder (Rosaceae)

+ (CAS) EMR: Castell’Arquato (Piacenza), muro a secco di Via Sforza Caolzio (WGS84: 44.851962N, 9.868245E), muro a secco, 198 m, 1 September 2020, D. Barberis, A. Mainetti, G. Nota (FI). – Casual alien species new for the flora of Emilia-Romagna.

A single specimen, about 1 m tall and bearing fruits, has settled in the interstices of a dry-stone wall near private gardens and vegetable gardens. The identification was done according to Rahn (1989) and Tomaszewski (2001) who reported the hairiness of the follicles as diagnostic. This is in contrast with the identification key by Pignatti et al. (2019), which uses the characters number of nerves per leaflet and direction of the follicles in the infructescence, thus giving a false determination in favour of the similar Sorbaria sorbifolia (L.) A.Braun.

D. Barberis, A. Mainetti, G. Nota

Stenotaphrum secundatum (Walter) Kuntze (Poaceae)

+ (CAS) CAL: Motta San Giovanni (Reggio Calabria), fraz. Lazzaro (WGS84: 37.973402N, 15.661162E), bordo strada, 4 m, 9 July 2021, G. Mei (REGGIO, Herb. G. Mei); Reggio Calabria (Reggio Calabria), Catona (WGS84: 38.190620N, 15.646328E), bordo strada, 20 m, 11 July 2021, leg. V.L.A. Laface, det. V.L.A. Laface, C.M. Musarella, G. Spampinato (FI, REGGIO). – Casual alien species new for the flora of Calabria.

V.L.A. Laface, G. Mei, C.M. Musarella

Tecomaria capensis (Thunb.) Spach (Bignoniaceae)

+ (CAS) LAZ: Gaeta (Latina), pendice W di Monte Orlando, Via Santa Maria Ausiliatrice (WGS84: 41.208235N, 13.581049E), boscaglie incolte sul bordo strada, 88 m, 9 January 2020, S. Ravetto Enri, M. Pittarello, M. Lonati (FI). – Casual alien species new for the flora of Lazio.

A small population of this species, occupying an area of approximately 5×5 m, has been found on the edge of the road between Gaeta and Monte Orlando. Several seedlings occur near an adult individual.

S. Ravetto Enri, M. Pittarello, M. Lonati

Ulmus pumila L. (Ulmaceae)

+ (NAT) TOS: Siena (Siena), Viale Sardegna (strada SR2) (WGS84: 43.327430N, 11.331531E), margini stradali e ruderi, 281 m, 14 June 2020, leg. E. Fanfarillo, det. E. Fanfarillo, T. Fiaschi, C. Angiolini (FI, SIENA); ibidem, 22 February 2021, leg. E. Fanfarillo, det. E. Fanfarillo, T. Fiaschi, C. Angiolini (FI, SIENA); ibidem, 13 April 2021, leg. T. Fiaschi, det. T. Fiaschi, E. Fanfarillo, C. Angiolini (FI, SIENA). – Naturalized alien species new for the flora of Toscana.

Ulmus pumila is present with several individuals, sometimes of medium-large size, colonizing roadsides, sidewalks, and wasteland.

E. Fanfarillo, T. Fiaschi, C. Angiolini

Yucca aloifolia L. (Asparagaceae)

+ (CAS) TAA: Naturno (Bolzano), Val Venosta (WGS84: 46.6506277N, 10.9882332E), radura boschiva di un bosco termofilo a roverella, 590 m, 1 August 2020, G. Bonari (FI). – Casual alien species new for the flora of Trentino-Alto Adige.

Sporadic individuals of this species were observed.

G. Bonari, E. Kindermann, C. Wellstein

Nomenclatural, status, distribution updates, and corrections to Galasso et al. (2018a) are provided in Suppl. material 1.

G. Galasso, F. Bartolucci

We gratefully acknowledge the Acta Plantarum staff, Sebastiano Andreatta, Daniela Longo, Francesco Roma-Marzio, and Davide Tomasi who provided distribution information, and Filip Verloove who confirmed the identification of the Scirpus atrovirens subspecies.