A review of the biology, distribution, and germination ecology of sticky nightshade (Solanum sisymbriifolium)

Sticky nightshade (Solanum sisymbriifolium Lam.) is a highly invasive, herbaceous weed of an increasing concern in agricultural and natural ecosystems worldwide. This annual or short-lived perennial plant, native to South America and accidentally introduced into Australia, competes aggressively with crops and pastures. Whereas its current infestations are more concentrated in New South Wales, it has also been reported, although less frequently, in Victoria, the ACT, and Queensland, raising concern about its potential spread. Sticky nightshade produces toxic steroidal glycoalkaloids that pose risks to livestock, and exhibits high ecological plasticity, allowing it to germinate under a wide range of climatic and soil conditions. Its prolific seed production, combined with the ability to propagate vegetatively, contributes to its rapid spread and persistence, making management difficult. Despite its invasiveness, no comprehensive review has yet synthesised the biology, distribution, and germination ecology of sticky nightshade. This review addresses that gap by examining key mechanisms underpinning its establishment and spread in agroecosystems. The paper also highlights critical knowledge gaps, particularly in seed dormancy, germination triggers, and reproductive ecology, and offers recommendations to guide future research and integrated management strategies.