PASSIONFRUIT

SCIENTIFIC NAME: Passiflora spp
FAMILY: Passifloraceae

Passionfruit vines are very commonplace in Central Queensland backyards. This plant belongs to a large family called Passifloraceae, which contains 400 species of Passiflora. Out of these 400 species only 50 to 60 types bear edible fruit, others are grown for their ornamental flowers.

There is an interesting story surrounding the naming of the passionfruit. It was named by Spanish priests, when colonising new lands, to explain the story of the crucifixion. The three styles represent the nails; the ovary, the sponge soaked in vinegar; the stamens, Christ's wounds; the filaments, the crown; and the the five petals and five sepals of the passion flower represent ten of Jesus' disciples (all but Judas who betrayed Jesus, and Peter who denied knowing Jesus).

The two most common types known are the yellow and the black/purple passionfruit. The yellow passionfruit or Passiflora edulis var. flavicarpa comes originally from the tropical Americas. It is a fast-growing plant and is used mainly for screening. The plant has large tendrils which allows them to attach themselves to any type of support. They are best trained over a fence or allowed to climb a tree. Observation has shown the vine produces more fruit if allowed to climb into a tree or planted in a windy area. The shaking of the flowers seems to set fruit better than those planted in a protected area. It also helps if you have two vines, as yellow passionfruit are self-sterile and need another to cross pollinate. They grow well in a wide range of soils but grow best in fertile, well-drained soils. They prefer good soil moisture, but hate to be waterlogged.

The yellow passionfruit has a large attractive white flower about 2-3 inches [5 cm] in diameter. The bloom is characterised by having long white or white purple filament-like rays. The fruits are globose to ellipsoid and are about 2 inches [5 cm] in diameter. They turn from green to yellow at maturity. The thin skin conceals a centre filled with yellowish gelatinous aromatic pulp and juice. Small edible black / brown seeds are embedded in the pulp. The pulp of the yellow passionfruit is slightly more acid than the purple one. The pulp is a good source of vitamin C and A, niacin and riboflavin.

The yellow fruit is generally prepared by cutting in two and scooping out the pulp with a spoon. It can be used for cake icing, frozen desserts, drinks and sherbets. The most popular passionfruit is the black/purple variety. It is also a climber which needs to be trained onto a trellis.

The soil needs to be well-drained and regular water is required. It usually doesn't survive on its own roots. It is very susceptible to fusarium wilt. Because of this, the black passion fruit is grafted onto a yellow passionfruit seedling as rootstock. When the vine is planted out, it must be kept under observation because the yellow vine will sometimes shoot out below the graft. This new shoot will grow vigorously and perhaps overtake the black vine, resulting in yellow fruit not black. Thus any shoots must be removed from under the graft. There are many hybrids available, some being 23E, Purple Gold and Lacey.

The black fruit is globose or oval with a black/purple-coloured rind. The yellow flesh has a superior taste to the yellow-skinned passionfruit. It is also a good source of vitamin A and C, riboflavin and niacin. It can also be used in sherbets, fruit salads, cakes and drinks. It can also be frozen in ice cube trays and used when needed. The rind is a very good source of high quality pectin.

Another relative is the granadilla or Passiflora quadrangularis. This plant grows one of the largest fruits in the passionfruit family. It comes from the tropical Americas as well. It is a very strong climbing vine and has much larger leaves than the passionfruit mentioned above. The stems are unusual in that they are quandrangular [four-angled] in cross section. The flowers are 4 inches [11 cm] in diameter and hang down so that the pink petals and filaments of blue and purple bands are not as showy as the other flowers. It is essentially a tropical vine liking high temperatures and high humidity. Little pollen is produced under dry conditions. In fact, the best way to ensure fruit set is to pollinate the flowers yourself. This is best done before 10 o'clock in the morning while the pollen is still moist. The pollen must be transferred from the anthers to the stigma. A finger, feather or brush can be used. Use the pollen of one flower to pollinate another. Check the diagram to get your bearings.

The ripening fruit is usually covered with a brown paper bag to protect the fruit from damage by birds and insects. The fruits can reach a length of 12 inches [30 cm] and turn yellowish and soft when ripe. The seeds are covered in a pulp which is usually strained and added to the rest of the fruit which has been skinned and diced. Orange juice and sugar is added to taste. It can also be added to fruit salads. The green fruit can be boiled and eaten as a vegetable. Granadillas contain phosphorous, calcium and iron.

Reprinted from: Capricornia Branch Newsletter, Vo1.14 No.4

DATE: August 1997

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