The petals become entirely green when the plant is in fruit. The plant is easily identified when in flower. However, the leaves of Harperocallis are almost identical to those of Narthecium and some species of Tofieldia , and in the vegetative condition identification would be difficult, even if the plants could be distinguished from surrounding grasses. Flowering occurs from mid-April through May and fruits are mature in July. Dispersal mechanisms and pollinators have not been studied.
Vegetative reproduction is by rhizomes.
The range has remained essentially the same as when the plant was first discovered in 1965. It has been found at three locations, all within the Apalachicola National Forest, approximately 19 miles apart along SR-65 in Franklin and Liberty Counties, Florida. These locations are within about O.3 miles of each other in Franklin County, while a third reported site is about 19 miles north in Liberty County. Attempts to relocate the alleged Liberty County location have been unsuccessful. Estimated plant population is several thousand plants.