PASSION-FLOWER (Passiflora), the typical genus of the family Passifloraceae, to which it gives its name. The name passion-flower—flos from the supposed resem blance of the corona to the crown of thorns, and of the other parts of the flower to the nails, or wounds, while the five sepals and five petals were taken to symbolize the ten Apostles—Peter, who denied, and Judas, who betrayed, being left out of the reckoning. There are about 30o species, mostly natives of western tropical South America ; others are found in various tropical and sub-tropical districts of both hemispheres. The tacsonias, by some considered to form part of this genus, inhabit the Andes at considerable elevations. They are mostly climbing plants having a woody stock and herbaceous or woody branches, from the sides of which tendrils are produced. Some few form trees of consider able stature destitute of tendrils, and with broad magnolia-like leaves in place of the more or less palmately-lobed leaves which are most generally met with in the family.
The inflorescence is usually of a cymose character. The flower consists of a receptacle varying in form from that of a shallow saucer to that of a long cylindrical or trumpet-shaped tube, and giving off from its upper border the five sepals, the five petals (rarely these latter are absent), and the threads or membranous processes constituting the "corona." This corona forms the most conspicuous and beautiful part of the flower of many species, and consists of outgrowths from the tube formed subsequently to the other parts; it is physiologically useful in favouring the cross fertilization of the flower by means of insects. From the base of the inner part of the tube of the flower, but quite free from it, uprises a cylindrical stalk surrounded below by a small cup-like outgrowth, and bearing above the middle a ring of five flat fila ments each attached by a thread like point to an anther. Above the ring of stamens is the ovary itself, upraised on a prolonga tion of the same stalk which bears the filaments, or sessile. The
stalk supporting the stamens and ovary is called the "gynophore" or the "gynandrophore," and is a characteristic of the family.
The ovary of passion-flowers is one-celled with three parietal placentas, and bears at the top three styles, each terminating by a large button-like stigma. The ovary ripens into a berry-like, very rarely capsular, fruit with the three groups of seeds arranged in lines along the walls, but im bedded in a pulpy arillus derived from the stalk of the seed. This succulent berry is in some cases highly perfumed, and affords a delicate fruit for the dessert-table, as in the case of the "granadilla" P. quadrangularis, also P. edulis, P.macrocarpa, and various species of Tacsonia known as "curubas" in Spanish South America ; P. laurifolia is the water-lemon, and P. maliformis the sweet cala bash of the West Indies. The fruits do not usually exceed in size a hen's or a swan's egg, but that of P. macrocarpa is a gourd-like oblong fruit attaining a weight of 7 to 8 pounds.
In the United States about I o native species of Passiflora occur, chiefly in the South and South-west. The passion-vine (P. incarnate), climbing I o to 3o ft. high, with pink and white flowers and a yellow, berry-like, edible fruit, 2 in. long, is found from Virginia to Missouri south to Florida and Oklahoma. The yellow passion-flower (P. lutea), of similar range, is a smaller plant, with greenish-yellow flowers and purple fruit.
The tacsonias, which in cultivation are often regarded as dis tinct, differ from Passiflora in having a long cylindrical calyx tube, bearing two crowns, one at the throat, the other near the base; they are stove or greenhouse plants; T. pinnatistipula, with pale rose-coloured flowers, a native of Chile and Peru, has long been in cultivation; T. and T. manicata, with handsome scarlet flowers, are among the finest species.