A new species of Sipapoantha (Gentianaceae: Helieae) from northern Brazil

A new species from Gentianaceae (tribe Helieae) is described from northern Brazil. Sipapoantha obtusisepala sp. nov. is distinct from the previously single member of the genus, Sipapoantha ostrina, by having a woody and branched habit, sessile and ovate leaves with an acute apex, and a smaller calyx with circular lobes. Sipapoantha obtusisepala is based on somewhat incomplete material and tentatively placed in Sipapoantha based on the presence of key generic characters such as coriaceous leaves with strongly revolute margins and blue corollas. It has only been recorded from one locality in the Brazilian-Guyana border area in the state of Roraima.