Passiflora mariquitensis Mutis ex L.Uribe, a Colombian endemic species that belongs to the subgenus Astrophea (DC.) Masters, was rediscovered in a disturbed forest in Mariquita (Tolima), where it has not been reported since 1784. We redescribe the species, providing data on morphology, ecology, and geographic distribution. It can be recognized from P. pittieri , its relative species, mainly by 6 or 10 lateral nerves to each side of the leaf, the yellow-white color of the four series of corona filaments, and the presence of rings in the nectary chamber. Passiflora mariquitensis is Critically Endangered due to its restricted occurrence, and conservation actions are urgent.