Passiflora edulis
Passiflora edulis, commonly known as passion fruit, is a vine species of passion flower native to southern Brazil through Paraguay and northern Argentina. It is cultivated commercially in tropical and subtropical areas for its sweet, seedy fruit. The fruit is a pepo, a type of berry, round to oval, either yellow or dark purple at maturity, with a soft to firm, juicy interior filled with numerous seeds. The fruit is both eaten and juiced, the juice often added to other fruit juices to enhance aroma. Etymology. The passion fruit is so called because it is one of the  many species of passion flower, the English translation of the Latin genus name, "Passiflora". Around 1700, the name was given by missionaries in Brazil as an educational aid while trying to convert the indigenous inhabitants to Christianity; its name was "flor das cinco chagas" or "flower of the five wounds" to illustrate the crucifixion of Christ, with other plant components also named after an emblem in the Passion of Jesus. Description. "Passiflora edulis" is a perennial vine; tendrils are borne in leaf axils, and have a red or purple hue when young. There are two main varieties: a purple-fruited  type, "P. edulis" f. "edulis", and the yellow-fruited "P. edulis" f. "flavicarpa". Usually the vine produces a single flower 5–7.5 cm wide at each node. The flower has 5 oblong, green sepals and 5 white petals. The sepals and petals are 4-6mm in length and form a fringe. The base of the flower is a rich purple with 5 stamens, an ovary, and a branched style. The styles bend backward and the stigmas, which are located on top of the styles, have a very distinct head. The fruit produced is entirely fleshy (making it botanically a berry ), and is spherical to ovoid. The outside color of the berry ranges from dark-purple with fine white specks to light yellow. The fruit is 4–7.5 cm in diameter; purple fruits are smaller, weighing around 35 grams, while yellow fruits are closer to 80 grams. The smooth, leathery rind is 9–13 mm thick, including a thick layer of pith. Within the berry, there are typically 250 black seeds, each 2.4 mm in length. Each seed is surrounded by a membranous sac filled with pulpy juice. The flavor of the juice is slightly acidic and musky. The passion fruit's flavor  can be compared to the guava fruit. Varieties. Several distinct varieties of passion fruit with clearly differing exterior appearances exist. The bright yellow "flavicarpa" variety, also known as yellow or golden passionfruit, can grow up to the size of a grapefruit, has a smooth, glossy, light and airy rind, and has been used as a rootstock for purple passionfruit in Australia. The dark purple "edulis" variety is smaller than a lemon, though it is less acidic than yellow passionfruit, and has a richer aroma and flavour. Uses. Passion fruit has a variety of uses related to its appealing taste as  whole fruit and juice. Nutrition. Raw passion fruit is 73% water, 22% carbohydrates, 2% protein and 0.7% fat (table). In a 100 gram reference amount, raw passion fruit supplies 97 calories and is a rich source (20% or more of the Daily Value, DV) of vitamin C (36% DV) and a moderate source (10-19% DV) of riboflavin, niacin, iron and phosphorus (table). No other micronutrients are in significant content. Phytochemicals. Several varieties of passionfruit are rich in polyphenol content, and yellow varieties of the fruit were found to contain prunasin and other cyanogenic glycosides in the peel and juice . Cultivation. Passion fruit is widely grown in tropical and semitropical regions of the world. In the United States, it is grown in Florida, Hawaii, and California. They generally have to be protected from frost, although certain cultivars have survived light frosts after heavy pruning of affected areas. Pollination. The flower of the yellow-fruited form of the passion fruit plant is self-sterile, while that of the purple-fruited form is self-compatible. In California, it is reported that pollination of flowers is most effective when done by the carpenter bee. There are three types of yellow passion fruit flowers , classified by curvature of style. To help assure the presence of carpenter bees, some gardeners place decaying logs near the vines, which provide shelter for the bees. Diseases. Viruses. Passion fruit woodiness virus is one of the most well-known viruses to the passion fruit. It belongs to the "Potyvirus" group and can attack a plant at any age from nursery to mature plants. Some features include yellow leaves that display distortion in the leaf length and shape. As well as affecting the leaf, this virus influences fruit shape and size. Affected fruits become stone-like and much smaller than  normal, with many fruits becoming scabbed and cracked. The virus is spread by sap-sucking insects such as aphids and mites. Woodiness can also spread through vegetation propagation such as infected scions or contaminated tools. There is no chemical control for this virus once the plant is infected, but the use of clean planting material can reduce its dissemination. One of the most serious viruses pertaining to vegetation is the cucumber mosaic virus. In the passion fruit, this virus appears with yellow mottling on leaves starting at random points on the vine and diminishing in intensity towards the tip. Expanding  leaves typically become twisted, curl downward, and develop a "shoestring" appearance as a result of a restriction of the leaf surface. It is mobile and can spread easily through interactions with other plants such as brushing between leaves. This virus is naturally transmitted through aphids and can also be transmitted mechanically through seedlings. Varietal resistance is the primary management tool, and eliminating weeds and infected perennial ornamentals that may harbor the virus is critical. Once the plant has been infected, there is no possible management of control for the virus. Phytoplasma. Overshooting is the term used when "Phytoplasma", a specialized  bacterium, attacks the phloem of a plant. "Phytoplasma" infection is characterized by chlorotic small leaves, shortening of internodes, excessive lateral shoots and abnormal flowers. Although there have been reports of this disease within the passion fruit plant, many infected plants are affected without visible signs of disease. Although "Phytoplasma" can be spread through grafting, it can be inhibited by periodic inspection of plant nurseries and areas that have had past infections. Overshooting responds to treatment with tetracycline, a common broad-spectrum antibiotic. Bacteria. Bacterial leaf spot, which causes vein clearing, forms bright yellow colonies causing infection and leaf wilt and , eventually, deterioration of fruit pulp, especially of young fruits. Under favorable conditions for the bacteria, infection occurs through natural openings or wounds from other pathogens that affect leaf inter-cellular spaces. Fertilizers or a copper chloride and mancozeb mixture can control the intensity of the disease, but are not a cure. The bacterial grease-spot of the passion fruit is caused by Pseudomonas syringae. It appears with olive-green to brown greasy-looking spots or brown, sunken circular lesions. On a later stage, a hard crust can cover the lesions showing a chlorotic halo. Affecting mainly the stomata, the grease -spot thrives in high temperatures and high relative humidity. To avoid infection, measures that may be adopted include planting seeds from healthy plants and using existing healthy areas. Fungicide controls can aid in preventing further infection. Fungal diseases. Collar rot disease is caused by the fungus "Fusarium solani". It is characterized by necrotic lesions at the collar region, browning of the stem at soil level, and dark discoloration of the stem. The rotting stem interferes with food and water transport within the plant, leading to withering of the plant until death. Infection occurs mostly through contaminated soil and infected plants  which cause the plants to survive for only a few weeks. There are no chemical controls. Management includes planting seedlings in unaffected areas and using clean tools. The fungus called fusarium wilt commonly occurs in adult plants and is caused by "Fusarium oxysporum". The pathogen has ability to survive for long periods, penetrating roots, invading the xylem and preventing the transport of water and nutrients to other organs of the plant. Once infected, this disease causes leaves to yellow and browning of the vascular system until it wilts and dies. It occurs in any type of soil infecting all plants . Management of crops include planting clean seedlings, uprooting and burning infected plants, and using sterilized tools. The anthracnose, a canker caused by "Colletotrichum gloeosporiodes", is a pathogen of the passion fruit creating dark and sunken lesions of the trunk. By attacking mature passion fruit trees, these lesions cause intense defoliation and fruit rot. Many leaves die due to the foliar lesions and the skin of fruits becomes papery. Under warm and humid conditions, this disease can worsen, causing red and orange spores eventually killing the plant. Infection is carried out through the residues of the passion flower, infected seeds, seedlings , and cuttings. Managing this disease involves a combination of using pathogen-free seedlings, eliminating infected areas, and improving ventilation and light conditions. Copper-based fungicides on injured areas can prevent the spread of disease. In culture. Passion fruit flower is the national flower of Paraguay. In 2006, singer-songwriter Paula Fuga released the popular song Lilikoi, the Hawaiian language word for passion fruit. The song is featured on an album also named after the fruit. Hip-hop artist Drake released the hit song "Passionfruit" in 2017.