During a field expedition to the northern parts of Iran, an alien species was collected from Lakan area, near Rasht (Gilan province ). It was identified as Verbena brasiliensis (Verbenaceae ). It is reported for the first time to the flora of Iran. V. brasiliensis is an erect perennial herb, (50– )100– 200 cm tall. Stem sharply quadrangular, numerous opposites branched, finely strigose above, gradually becoming glabrous towards the base. Lower and median leaves 4. 5– 5. 5 cm long, 1. 5– 2 cm wide, rhombic-lanceolate or lanceolate, sub petiolate, lamina elliptic-lanceolate, gradually tapering to the base and pointed at the top, margins irregularly serrate, and entire at the base. Spikes cylindrical, numerous, terminal, compressed or slightly spaced at the base, (1– )1. 5– 4. 5 (– 10 ) cm long, 3– 4. 5 mm wide. Spikes triad, central sessile or less pedunculate. Bracts and calyx, narrow-lanceolate, covered with appressed hairs, 2. 2– 2. 5 mm long. Corolla bluish-purple, hairy at above calyx, corolla tube 2. 5– 3. 5 mm long, corolla lobes 1 mm long. Nutlets oblong, 1. 5– 1. 9 mm long, white-papillate on flattened ventral surface, wrinkled on dorsal surface, longitudinally ribbed. Specimen examined: Iran: Gilan province, Rasht, Lakan, 20 m, 10. 07. 2021, 37° 13'50. 2" N, 49° 36'42/17" E (GILAN-6400 ) (Fig. 1 ). This species originates from South America, but now it has been naturalized to North America, South Africa, Oceania, Europe and the Caucasus (Georgia's Black Sea coast). The plant mostly grows in wet habitats such as: river banks, lakes, coastal prairies. The species is characterized by confinement to the second common disturbed habitats: disturbed soils, pastures, agricultural arable land, wastelands near fences, gravelly lands, roadsides, and railway tracks (Melnikov 2014 ). In the study area, it has a dense growth on the disturbed soils around the channels and the cement wall, and also scattered in the pasture of the flood plains beside some plants such as: Juncus effussus L., Paspalum distichum L. accompanied by Solanum sisymbriifolium Lam., Phytolaca americana L., Artemisia annua L., Digitaria sanguinalis (L. ) Scop., Erigeron canadensis L., Paspalum dilatatum Poir., Sambucus ebulus L., Lycopus europaeus L., Silybum marianum (L. ) Gaertn., Rubus sanctus Schreb., and Pulicaria dysenterica (L. ) Gaertn. In the modern world, one of the most threat for the biodiversity, is adventive invasive species (Mikeladze et al. 2017 ). Caspian Sea coasts has a suitable climate for the establishment and spread of alien plants due to its humid climate and lack of severe winter cold. In recent years, numerous imported plants with high invasion behavior have been reported from the Caspian coasts, especially Guilan province such as: Ambrosia artemisiifolia L. (Mozaffarian 1991 ), Sida rhombifolia L. (Amini et al. 2003 ), Amaranthus spinosus L. (Mohamadzadeh et al. 2005 ), Tagetes minuta L. (Naqinezhad & Saeidi Mehrvarz 2007 ), S. sisymbriifolium (Eslami & Naqinezhad 2010 ), Eichhornia crassipes (Mart. ) Sloms (Mozaffarian & Yaghoubi 2015 ), A. psilostachya DC. (Tokasi et al. 2017 ), and Pistia stratiotes L. (Bidarlord et al. 2019 ). This species is invasively increasing in several parts of Europe and North America (Verloove 2011 ). Fully grown plant in the second year develops about 90, 000– 100, 000 seeds (Mikeladze et al. 2017 )and forms a dense cover. It is a threat to native plants and could cause their extinction. So far in Iran, the species is only collected and observed in the study area with a limited extent. Mechanical and chemical controls are advised if necessary which could be efficient at the introduced phase to eradicate this species.