A new species, Acanthosyris annonagustata C. Ulloa gr P. Jorgensen, fr
om Nape, Ecuador, is described and illustrated. This species is charac
terized by its golden brown puberulent inflorescence and fruit. The pl
ant is used in local medicine, and the fruits taste like Annona and ar
e eaten by monkeys. In Ecuador, Acanthosyris is also represented by A.
glabrata (Stapf) Stauffer from the dry western forests. a tree that w
e are also reporting for the first time from Peru.