Abstract
Monochoria hastata is a tropical aquatic herb, almost entirely restricted to its native distribution of South-East Asia and Oceania (Boonkerd et al., 1993). It is a weed of rice fields in South-East Asia, with a prolific seed production and a high capacity to reproduce vegetatively (Ali et al., 2018). It is only listed as invasive in rice fields in Singapore, without further details (PIER, 2019). M. hastata is not reported as invasive in natural habitats; nor is there information about its effects on biodiversity. Outside its native range, M. hastata is reported as expected to spread and invade rice fields in Pakistan, facilitated by flooding events associated to monsoon rains (Ali et al., 2018). Although is not found in the New World, M. hastata is declared as a Federal Noxious Weed in the USA, because of the detrimental effects it could cause to agriculture (Coile, 1996). In Oceania, M. hastata is reported only as cultivated in Fiji, without further details (PIER, 2019). In the Northern Territory of Australia, M. hastata is classified as vulnerable because of the deterioration of aquatic habitats and the invasion of exotic weeds (India Biodiversity Portal, 2019).