This species is similar to Chiococca alba in general aspect and characters. It is a narrow endemic of (apparently) one offshore island in the Atlantic Ocean off northeastern Brazil. Chiococca insularis differs from Chiococca alba in its purple-black rounded fruits with usually more than two pyrenes.
Chiococca and Erithalis are similar, and these fruit characters are more similar to Erithalis as noted by Zappi & Nunes (2000). At the time they studied this species, Erithalis was characterized by an erect shrub habit and rounded, purple-black fruits with 5-6 pyrenes, while Chiococca was characterized by a scandent habit and flattened white fruits with 2 pyrenes. However, Chiococca also includes also erect trees (e.g., Chiococca pachyphylla), and some species with purple to purple-black fruits (e.g., Chiococca nitida). Some fruits of Chiococca insularis have 2 pyrenes as in other Chiococca species, and Erithalis is endemic to the Caribbean basin. Jardim et al. (2015) transferred this species to Chiococca based on these characters and its biogeographic range. Paudyal et al. (2018) did not include Chiococca insularis in their molecular analysis of this group. They did expand the circumscription of Salzmannia to include Salzmannia plowmanii, which is quite similar to Chiococca insularis and found in the adjacent mainland, and Chiococca insularis may deserve re-evaluation as to whether it is better classified in Salzamnnia (and distinct from Salzmannia plowmanii, now that it is better documented by Figueira et al., 2020).
Chiococca insularis was long known only from the type, and its generic status was problematic. This was due at least in part to an inaccurate original description (Jardim et al., 2015) and the holotype specimen not being located for many years (Negrón-Ortiz, 2005). This specimen was not found because a later botanist identified it as Chiococca alba apparently without being aware it was a type, and it was filed under that species while other authors were looking for it in Palicourea and Erithalis.