Passiflora

Passiflora, known also as thepassion flowersorpassion vines, is agenusof about 550speciesofflowering plants, thetype genusof thefamilyPassifloraceae.
They are mostlytendril-bearingvines, with some beingshrubsortrees. They can bewoodyorherbaceous.
Passion flowers produce regular and usually showyflowerswith a distinctivecorona. There can be as many as eight concentric coronal series, as in the case ofP. xiikzodz.andPassiflora alata. The hallmark of the genus is theandrogynophore, a central column to which thestamensandpistilare attached, which can be very long in some species such asPassiflora coactilis. The flower ispentamerous(except for a fewSoutheast Asianspecies) and ripens into anindehiscent fruitwith numerous seeds.
The fruit ranges from 5–20 centimetres (2–8 in) long and 2.5–5 cm (1–2 in) across, depending upon the species orcultivar.
Many species ofPassiflorahave been found to containbeta-carbolineharmala alkaloids,some of which areMAO inhibitors. The flower and fruit have only traces of these chemicals, but the leaves and the roots often contain more.The most common of these alkaloids isharman, butharmaline,harmalol,harmine, andharmolare also present.The species known to bear such alkaloids include:P. actinia,P. alata(winged-stem passion flower),P. alba,P. bryonioides(cupped passion flower),P. caerulea(blue passion flower),P. capsularis,P. decaisneana,P. edulis(passion fruit),P. eichleriana,P. foetida(stinking passion flower),P. incarnata(maypop),P. quadrangularis(giant granadilla),P. suberosa,P. subpeltataandP. warmingii.
Other compounds found in passion flowers arecoumarins(e.g.scopoletinandumbelliferone),maltol,phytosterols(e.g.lutenin) andcyanogenic glycosides(e.g.gynocardin) which render some species, i.e.P. adenopoda, somewhat poisonous. Manyflavonoidsand theirglycosideshave been found inPassiflora, includingapigenin,benzoflavone,homoorientin,7-isoorientin,isoshaftoside,isovitexin(orsaponaretin),kaempferol,lucenin,luteolin,n-orientin,passiflorine(named after the genus),quercetin,rutin,saponarin,shaftoside,viceninandvitexin. Maypop,blue passion flower(P. caerulea), and perhaps others contain theflavonechrysin. Also documented to occur at least in somePassiflorain quantity are thehydrocarbonnonacosaneand theanthocyanidinpelargonidin-3-diglycoside.
The genus is rich inorganic acidsincludingformic,butyric,linoleic,linolenic,malic,myristic,oleicandpalmitic acidsas well asphenoliccompounds, and theamino acidα-alanine.Esterslikeethyl butyrate,ethyl caproate,n-hexyl butyrateandn-hexyl caproategive the fruits their flavor and appetizing smell.Sugars, contained mainly in the fruit, are most significantlyd-fructose,d-glucoseandraffinose. Amongenzymes,Passiflorawas found to be rich incatalase,pectin methylesteraseandphenolase.
Passiflorais the most species rich genus of both the family Passifloraceae and the tribe Passifloreae. With over 550 species, an extensive hierarchy of infrageneric ranks is required to represent the relationships of the species. The infrageneric classification ofPassifloranot only uses the widely used ranks of subgenus, section and series, but also the rank of supersection.
The New World species ofPassiflorawere first divided among 22 subgenera by Killip (1938) in the first monograph of the genus.More recent work has reduced these to 4, which are commonly accepted today (in order from most basally to most recently branching):
Some studies have shown that the segregateOld WorldgeneraHollrungiaandTetrapathaeaare nested withinPassiflora, and form a fifth subgenus (Tetrapathaea).Other studies support the current four subgenus classification.
Relationships below the subgenus level are not known with certainty and are an active area of research. The Old World species form two clades – supersectionDisemma(part of subgenusDecaloba) and subgenusTetrapathaea. The former is composed of 21 species divided into sectionsDisemma(three Australian species),Holrungiella(one New Guinean species) andOctandranthus(seventeen south and east Asian species).
The remaining (New World) species of subgenusDecalobaare divided into seven supersections. SupersectionPterospermaincludes four species fromCentral Americaand southern Mexico. SupersectionHahniopathanthusincludes five species from Central America,Mexicoand northernmostSouth America. SupersectionCiceaincludes nineteen species, with apetalous flowers. SupersectionBryonioidesincludes twenty-one species, with a distribution centered on Mexico. SupersectionAuriculataincludes eight species from South America, one of which is also found in Central America. SupersectionMultifloraincludes nineteen species. SupersectionDecalobaincludes 123 species.
Passiflorahas a largelyneotropicdistribution, unlike other genera in the familyPassifloraceae, which includes more Old World species (such as the genusAdenia). The vast majority ofPassifloraare found in Mexico, Central America, the United States and South America, although there are additional representatives inSoutheast AsiaandOceania.New species continue to be identified: for example,P. xishuangbannaensisandP. pardifoliahave only been known to the scientific community since 2005 and 2006, respectively.
Some species ofPassiflorahave been naturalized beyond their native ranges. For example, theblue passion flower(P. caerulea) now grows wild in Spain.Thepurple passionfruit(P. edulis) and its yellow relativeflavicarpahave been introduced in many tropical regions as commercial crops.
Passion flowers have floral structures adapted forbiotic pollination. Pollinators ofPassifloraincludebumblebees, carpenter bees (e.g.,Xylocopa sonorina),wasps,bats, andhummingbirds(especiallyhermitssuch asPhaethornis); some others are additionally capable ofself-pollination.Passifloraoften exhibit high levels of pollinator specificity, which has led to frequent coevolution across the genus. Thesword-billed hummingbird(Ensifera ensifera) is a notable example: it, with its immensely elongated bill, is the sole pollinator of 37 species of highAndeanPassiflorain the supersectionTacsonia.
The leaves are used for feeding by thelarvaeof a number of species ofLepidoptera. Famously, they are exclusively targeted by many butterfly species of the tribeHeliconiini. The many defensive adaptations visible onPassiflorainclude diverse leaf shapes (which help disguise their identity), colored nubs (which mimic butterfly eggs and can deter Heliconians from ovipositing on a seemingly crowded leaf),extrafloral nectaries,trichomes,variegation, and chemical defenses.These, combined with adaptations on the part of the butterflies, were important in the foundation ofcoevolutionary theory.
Recent studies have shown that passiflora both grow faster and protect themselves better in high-nitrogen soils. In low-nitrogen environments, passiflora focus on growth rather than defense and are more vulnerable to herbivores.
The following lepidoptera larvae are known to feed onPassiflora:
The generally high pollinator and parasite specificity inPassifloramay have led to the tremendous morphological variation in the genus. It is thought to have among the highestfoliardiversity among all plant genera,with leaf shapes ranging from unlobed to five-lobed frequently found on the same plant.Coevolutioncan be a major driver of speciation, and may be responsible for the radiation of certain clades ofPassiflorasuch asTacsonia.
Thebractsof thestinking passion flowerare covered by hairs which exude a sticky fluid. Many small insects get stuck to this and get digested tonutrient-rich goo byproteasesandacid phosphatases. Since the insects usually killed are rarely majorpests, this passion flower seems to be aprotocarnivorous plant.
Banana passion floweror "banana poka" (P. tarminiana), originally from CentralBrazil, is aninvasiveweed, especially on the islands ofHawaii. It is commonly spread byferalpigseating the fruits. It overgrows and smothers stands ofendemicvegetation, mainly on roadsides.Blue passion flower(P. caerulea) is an invasive species in Spain and considered likely to threaten ecosystems there.
On the other hand, some species areendangereddue to unsustainableloggingand other forms ofhabitat destruction. For example, the Chilean passion flower (P. pinnatistipula) is a rare vine growing in the TropicalAndessouthwards fromVenezuelabetween 2,500 and 3,800 metres (8,200 and 12,500 ft) in altitude, and in Coastal Central Chile, where it only occurs in a few tens of square kilometres of fog forest by the sea, near Zapallar.P. pinnatistipulahas a round fruit, unusual inTacsoniagroup species like banana passion flower andP. mixta, with their elongated tubes and brightly red to rose-colored petals.
Notable and sometimes economically significantpathogensofPassifloraare severalsac fungiof the genusSeptoria(includingS. passiflorae), the undescribedproteobacteriumcalled "Pseudomonas tomato" (pv.passiflorae), thePotyviruspassionfruit woodiness virus, and theCarlavirusPassiflora latent virus.
Passion flower is not recommended during pregnancy because it may induce contractions.Consuming passion flower products may cause drowsiness,nausea, dizziness, abnormalheart rhythms,asthma, orrhinitis.
A number of species ofPassifloraare cultivated outside their natural range for both their flowers and fruit. Hundreds of hybrids have been named; hybridizing is currently being done extensively for flowers, foliage and fruit. The following hybrids and cultivars have gained theRoyal Horticultural Society'sAward of Garden Merit:
During theVictorian erathe flower (which in all but a few species lasts only one day) was very popular, and many hybrids were created using thewinged-stem passion flower(P. alata), theblue passion flower(P. caerulea) and other tropical species.
Many cool-growingPassiflorafrom the Andes Mountains can be grown successfully for their beautiful flowers and fruit in cooler Mediterranean climates, such as theMonterey BayandSan FranciscoinCaliforniaand along the western coast of the U.S. intoCanada. One blue passion flower or hybrid even grew to large size atMalmö Central StationinSweden.
Passion flowers have been a subject of studies investigatingextranuclear inheritance;paternalinheritance ofchloroplastDNA has been documented in this genus.Theplastomeof thetwo-flowered passion flower(P. biflora) has beensequenced.
Most species have round or elongated edible fruit.
A native source ofbeta-Carbolines(e.g., passion flower in North America) is mixed withDesmanthus illinoensis(Illinois bundleflower) root bark to produce a hallucinogenic drink called prairiehuasca, which is an analog of the shamanic brewayahuasca.
Passiflora incarnata(maypop) leaves and roots have a long history of use as atraditional medicinebyNative Americansin North America and were adapted byEuropean colonists.The fresh or dried leaves of maypop are used to make a tea that is used as asedative.Passionflower as dried powder or anextractis used as adietary supplement.There is insufficientclinical evidencefor using passionflower to treat any medical condition.
Passionflower is classified asgenerally recognized as safefor use as afood ingredientin the U.S.
Thepassioninpassion flowerpurportedly refers tothe passion of JesusinChristian theology;the wordpassioncomes from theLatinpassio, meaning 'suffering'. In the 15th and 16th centuries, Spanish Christian missionaries adopted the unique physical structures of this plant, particularly the numbers of its various flower parts, as symbols of the last days ofJesusand especially hiscrucifixion:
The flower has been given names related to this symbolism throughout Europe since the 15th century. InSpain, it is known asespina de Cristo('thorn of Christ'). OlderGermanicnamesincludeChristus-Krone('Christ's crown'),Christus-Strauss('Christ's bouquet'),Dorn-Krone('crown of thorns'),Jesus-Lijden('Jesus' passion'),Marter('passion')orMuttergottes-Stern('Mother of God's star').
Outside the Roman Catholic heartland, the regularly shaped flowers have reminded people of the face of aclock. InIsraelthey are known as "clock-flower" (שעונית) and in Greece as "clock plant" (ρολογιά); inJapantoo, they are known astokeisō(時計草, 'clock plant'). In Hawaiian, they are calledlilikoʻi;līis a string used for tying fabric together, such as ashoelace, andlikomeans 'to spring forth leave'.
InIndia, it is known asKrishnakamalabecause of its relation to the EpicMahabharata. The 100 peripheral petals represent the 100Kauravas, while the 5 yellow petals in between stand for thePandavas. The sensitive, but firm green bulb on top isDraupadi, orKrishna.