Note: Information is dated. Do not rely on it.Passion Flower. A large genus of twining plants belonging to the natural order Passifloraceae. They are all twining plants, often scrambling over trees to a considerable length, and in many cases are most beautiful objects, on account of their large, rich, or gaily-colored flowers, which are often succeeded by orange-colored edible fruits, for which indeed they are chiefly valued in the countries where they grow wild. Passiflora laurifolia produces the water lemon of the West Indies, and passiflora maliformis bears the sweet calabash. The name is applied more especially to passiflora caerulea, which is commonly cultivated in England out of doors, and is the one to which the genus owes its name.