The St. Helena Darter is endemic to St. Helena Island and is known only from St. Helena. There are very few published records. The type series (four males, one female) was collected during the U.S. Solar Eclipse expedition between 20th February and 10th March 1889-1890. The last known record, a female, was collected at Green Hill in October 1963. Because there were no records since then the species was assessed as Extinct. However, there was never a systematic survey for the species not before and particularly not since the last record. There is also not aware of any entomological survey, which may have paid attention to the species. Thus, although the likelihood is high that the species is now Extinct it is unable to exclude that populations still remain. Because of the insufficient surveying during the last 50 years, the current accessment by IUCN Red List on this species is Data Deficient rather than Critically Endangered (possibly extinct).

The specimen record of the species length at 30mm and 36mm, meaning they are one of the largest species in the genus Sympetrum.