Distribution and ecology of wild lettuces Lactuca serriola L. and Lactuca virosa L. in central Chile

Wild lettuces (Lactuca L.) provide valuable genetic resources for crop breeding, but are also significant invasive weeds. We explored the distributions, habitats, and ecological characteristics of populations of wild Lactuca species in central Chile. We documented two species – Lactuca serriola L. (prickly lettuce) and Lactuca virosa L. (opium/bitter lettuce) in 204 localities. These observations indicate that: i) both allochthonous (Euroasian) Lactuca species occur and are able to regenerate in central Chile; ii) L. serriola forms dense populations in urbanized areas; iii) both species can expand along transport corridors to high elevations; iv) the spread of L. virosa and persistence of dense populations in elevations above 2,000 m a.s.l. prove the invasiveness of this species in extreme climates; v) both species may contain novel traits of interest for germplasm conservation.