Habit: Spermacoce felis-insulae grows as a perennial up to 25 cm in height spreading to form mats. The leaves are arranged oppositely with triangular stipules between the petioles. The recurved leaves are linear up to 1 cm long (typically shorter), with an acute leaf apex and an entire margin. The leaves are slightly plicate forming a keel like appearance.
The complete, perfect, actinomorphic, solitary flowers occur in the leaf axils and terminate branches. A stipular sheath subtends the flowering “head”. The calyx has 4 unfused, triangular sepals. The corolla has 4 fused pubescent white petals that form a short, puberlent tube and each recurved lobe with a mucronate apex. There are 4 stamens that are fused to the perianth forming a hypanthium. The ovary is inferior with 1 locule and many ovules. The fruit is a capsule at maturity.
Habitat: Spermacoce felis-insulae grows in Dunes.
Distribution: Spermacoce felis-insulae is a single island endemic occurs on two small sand spits at the south western end of Cat Island.
Medicinal/Cultural/Economic usage: Spermacoce felis-insulae is not known to be used medicinally in the Lucayan Archipelago.
It is Redlisted by the International Union for the Conservation of Nature (IUCN) as a Critically Endangered species.