[3] José Jerónimo Triana and Jules Émile Planchon, the botanists who first formally described the species, named it after its large flowers (Latinized forms of Greek μακρoς, macros and ανθος, anthos).

Its solitary Inflorescences occur in the axils of leaves on short, 5-6 millimeter long pedicels.

Its large flowers have 3 sepals that are fused to form bell-shaped calyx that are 8-10 by 10-11 millimeters.

The lobes of the calyx are triangular, covered in silky hairs, and have shallowly pointed tips.

[7] It has been observed growing in tropical rainforests and seasonal forests at elevations of 0-550 meters.