Abstract: Coastal Karnataka comprises three coastal districts. The biodiversity is rich and unique in this region because western ghats pass through these coastal districts. These regions are under threat due to natural and anthropogenic factors. Biological invasion by alien species is one such threat that falls under both categories. Now the alien flora has become naturalized and has become part of native flora. Some plant species have become beneficial because of their medicinal value. However, the threat to biodiversity cannot be ignored due to invasive behavior by some species.
The present paper attempts to identify and document the diversity of alien and naturalized flora of coastal regions of Karnataka with ethnobotanical uses of some plant species. Altogether 74 species of flowering plants belonging to 29 families have been identified. The habit-wise analysis of the plants indicates the presence of 63 herbs, followed by 09 shrubs, 02climbers, and 02 trees. Asteraceae is the most dominant family with 13 species. The region accounts for 42% of the alien flora of the country. Of the 74 species of recorded plants, 21 are used for various medicinal and other uses by the indigenous communities and tribals in the study area.

Keywords: Coastal Karnataka, Invasive Alien flora, Diversity, Ethnobotany

| DOI: 10.17148/IARJSET.2021.81223