The non-native Areca triandra palm is a potential threat to the Southwestern rainforests of Sri Lanka

The palm family is a major source of invasive plants because of their long history of introductions outside their native range in tropical and subtropical regions for their use as food and ornamentals. Areca triandra was introduced to Sri Lanka in 1867 through the Royal Botanic Gardens, Peradeniya and has been grown as an ornamental for over a century. To assess its potential invasiveness, we applied an invasiveness assessment protocol. Population and reproductive characteristics were studied in Meethirigala and Yagirala Forest Reserves. In each location, stems > 1 m in height were sampled and crown cover was assessed in three plots of 400 m2 (20 × 20 m) and the ground layer < 1 m height sampled through four 1 x 1 m quadrats within each 400 m2 (total of 24 quadrats). Areca triandra accounted for 56 - 66% of stems > 1 m height, 52 - 76% crown cover, and 64 - 77% of saplings and seedlings in the ground layer < 1 m height. Clump formation was high with 30 - 51% having 2 - 7 ste..., , , # The non-native *Areca triandra* palm is a potential threat to the Southwestern rainforests of Sri Lanka

[https://doi.org/10.5061/dryad.70rxwdc8b](https://doi.org/10.5061/dryad.70rxwdc8b)

## Description of the data and file structure

This dataset contains statistical analyses and supplementary materials related to our study on the invasive potential of *Areca triandra* in Sri Lanka’s Southwestern rainforests. The data support our findings on species distribution, ecological impacts, and citizen science contributions for the investigation of this species in Sri Lanka. Supplementary materials include: Appendix 1: Invasiveness assessment protocol, Appendix 2: Species above 1 m height in the study plots, Appendix 3: Results from citizen science survey and Appendix 4: Data collected on infructescence of *Areca triandra*.

### Files and variables

**Statistical Analysis:** To identify any significant difference between *A. triandra* and other species in each site (MFR and YFR) and height...,