Solanum trisectum Dunal is an endemic Solanaceae of Madeira Island (Portugal), considered critically endangered
due to its extreme rarity. Since its discovery this species has shown a narrow distributional range mainly on the
northern side of the island, with scattered and small populations and large time gaps between sightings. The present
work aimed to understand the underlying ecological underpinnings for this species rarity towards an effort to
increase the success of conservation actions. Data on historical locations, environmental conditions field surveys,
reinforcement in situ and ex situ germination trials were obtained. The species was found to currently occur only
in two wild populations and two reinforcement sites, amounting to twenty-four plants in total. Statistical analysis of
these data related wild populations and successful reinforcement sites, separating them from other sites where the
reinforcement did not succeed. This suggests that the successful reinforcement sites showed conditions more similar
to wild population sites compared to non-successful ones. The data obtained supports the hypothesis that S. trisectum
distribution and rarity is determined by species specific habitat needs, i.e., abiotic conditions, which have been for
the first time assessed during the present work. Further, this study also reinforces the classification of S. trisectum as
a top priority species for conservation.Prospecting, Monitoring and Conservation of Normania triphylla in Madeira
(Mohamed bin Zayed Species (project number 13255498)) and Madeira PO 14-20, contract CASBIO (ref M1420-01-
0145-FEDER-000011 ).info:eu-repo/semantics/publishedVersio