Introduction Larches are commonly known trees that for a long time have been the subject of interest because of their valuable wood and resin and unquestionable decorative features. The representatives of Larix genus occur in the cool and mod- erate zone of the northern hemisphere – in Eurasia and North America. Some Larix species reach far to the north, delineating the northern line of forests, as Larix occidental- is [1], and even entering the tundra, an example of which can be Larix gmelinii in Asia [2]. Larches are characterized by big or intensive growth, especially in the juvenile period, but in our climatic condi- tions they terminate growth quickly and do not reach big sizes or heights. Larches have modest soil requirements, although they grow best on soils that are rich enough in nutrients, humid enough, and well-aerated. Larix genus trees are light-loving plants. They display high resistance to low temperatures and wind. They also show relatively big Pol. J. Environ. Stud. Vol. 23, No. 3 (2014), 867-874 Original Research Roadside Larch Trees (Larix Mill.) and Its Female Generative Organs as a Biomonitor of Air Pollution Aleksandra Seta-Koselska 1 , Ewa Szczuka 2 *, Ewa Skórzyńska-Polit 1 , Marcin Domaciuk 2 , Irena Giełwanowska 3 ** 1 Department of Plant Physiology and Biotechnology, Institute of Biotechnology, John Paul II Catholic University of Lublin, Konstantynów 1h, 20-708 Lublin, Poland 2 Department of Plant Anatomy and Cytology, Institute of Biology, UMCS University, Akademicka 19, 20-033 Lublin, Poland 3 Department of Plant Physiology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland Received: 10 October 2013 Accepted: 10 March 2014 Abstract The disturbances in the morphology and anatomical structure of female generative organs were investi- gated in two species of roadside larch trees Larix decidua Mill., L. decidua subsp. polonica, and L. kaempferi (Lamb.) Carr., within the administrative boundaries of the city of Lublin. The irregularities of female cones appear more often at the juvenile stage of their development. Completely dried cones or cones with partially dried scales were observed on the L. decidua trees growing in a more polluted environment (in comparison with the place of growing of control trees). Among the more developmentally advanced cones, partially dried and completely deformed or bent female generative organs with a disturbed anatomical structure were visible. Peroxidase activity was significant higher in L. decidua subsp. polonica located near the street with heavy traf- fic. The study can be used as a basis for deeper and more detailed investigations of reproduction of larches in different environments with air pollution in the area of Lublin and its vicinity. Maybe roadside larches and its generative organs can be used as possible biomonitors of air pollution in urban conditions. Keywords: Larix, female generative organs, disturbances, guaiacol peroxidase, air pollution *e-mail: ewa.szczuka@poczta.umcs.lublin.pl **e-mail: i.gielwanowska@uwm.edu.pl