Mirabilis jalapa, the marvel of Peru or four o'clock flower, is the most commonly grown ornamental species of Mirabilis plant, and is available in a range of colours. Mirabilis in Latin means wonderful and Jalapa is the capital of Veracruz. Mirabilis jalapa was cultivated by the Aztecs for medicinal and ornamental purposes. It is also said to have been exported from the Peruvian Andes in 1540 A.D.
Flowers and colour
A curious aspect of M. jalapa is that flowers with different colours grow simultaneously on the same plant.
Additionally, an individual flower can be splashed with different colours. Flower patterns are referred to as sectors (whole sections of flower), flakes (stripes of varying length), and spots. A single flower can be plain yellow, pink or white, or have a combination of sectors, flakes and spots. Furthermore, different combinations of flowers and patterns can occur on different flowers of the same plant. Another interesting point is a colour-changing phenomenon. For example, in the yellow variety, as the plant matures, it can display flowers that gradually change to a dark pink colour. Similarly white flowers can change to light violet.
The flowers usually open from late afternoon (around 4'o clock) onwards, hence the first of its common names. Flowers then produce a strong, sweet-smelling fragrance throughout the night, then close for good in the morning. New flowers open the following day.
Habitat and cultivation
Mirabilis jalapa hails from tropical South America, but has become naturalised throughout tropical and warm temperate regions. In cooler temperate regions, it will die back with the first frosts, regrowing in the following spring from the tuberous roots. The plant does best in full sun. It grows to approximately 0.9 m in height. The single-seeded fruits are spherical, wrinkled and black upon maturity (see picture), having started out greenish-yellow. The plant will self-seed, often spreading rapidly if left unchecked in a garden. Some gardeners recommend that the seeds should be soaked before planting, but this is not totally necessary. In North America, the plant perennializes in warm, coastal environments, particularly in USDA Zones 9–10. The fragrance of the flower is more intense and noticeable during the warm period of the day. Usually, the flowers are found in yellow, pink and white colors but you can find different combination of flowers growing on the same single four O’ clock plant! 
Around 1900, Carl Correns used Mirabilis as a model organism for his studies on cytoplasmic inheritance. He used the plant's variegated leaves to prove that certain factors outside the nucleus affected phenotype in a way not explained by Mendel's theories. Correns proposed that leaf colour in Mirabilis was passed on via a uni-parental mode of inheritance.
Also, when red-flowered plants are crossed with white-flowered plants, pink-flowered offspring, not red, are produced. This is seen as an exception to Mendel's Law of Dominance, because in this case the red and white genes are of equal strength, so neither completely dominates the other. The phenomenon is known as incomplete dominance.
Bioassay-guided fractionation of an organic extract of the cell mass from a manipulated plant cell culture of M. jalapa led to the isolation and subsequent identification of an isoflavone, a roteinoid and a dehydrorotenoid, Two of these compounds are responsible for the antimicrobial activity against Candida albicans.
Bioassay-guided fractionation of the methanolic extract of M. jalapa also led to the isolation of an active polyphenolic amide: N-trans-feruloyl 4′-O-methyldopamine. This compound shows moderate activity as an efflux pump inhibitor against multidrug-resistant Staphylococcus aureus.
The flowers are used in food colouring. The leaves may be eaten cooked as well, but only as an emergency food.
An edible crimson dye is obtained from the flowers to colour cakes and jellies.
In herbal medicine, parts of the plant may be used as a diuretic, purgative, and for vulnerary (wound healing) purposes. The root is believed an aphrodisiac as well as diuretic and purgative. It is used in the treatment of dropsy.
The leaves are used to reduce inflammation. A decoction of them (mashing and boiling) is used to treat abscesses. Leaf juice may be used to treat wounds.
- In Bangladesh it is called sandhyamalati (Bengali: সন্ধ্যামালতী), meaning "evening flower".
- In Pakistan it is called gul adnan (Urdu: گل عدنان) or gul-e-abbas (Urdu: گل عباس).
- In Sri Lanka it is called hendirikka (Sinhalese: හෙන්දිරික්කා).
- In Karnataka it is called sanje mallige (Kannada: ಸಂಜೆ ಮಲ್ಲಿಗೆ).
- In Tamil Nadu it is called andhi mandhaarai (Tamil: அந்தி மந்தாரை).
- In Thailand it is called bānyĕn (Thai: บานเย็น), meaning "evening blossom".
- In Andhra Pradesh it is called chandrakantha indraganti (Telugu: చంద్రకాంత ఇంద్రగంటి).
- In Bulgaria it is called noshna krasavica (Bulgarian: ношна красавица), which means "night beauty", "night belle".
- In Germany it is called Wunderblume, which means "flower of miracle".
- In Kerala it is called naalumani poovu (Malayalam: നാലുമണിപ്പൂ, പതിറ്റടിമുല്ല).
- In Maharashtra it is called gulabakshi (Marathi: गुलबक्षी).
- In Assam it is called godhuli gopal (Assamese: গধূলিগোপাল), godhuli meaning "evening".
- In Maithili it is called sanjhaa phool as it blooms in evening.
- In Orissa it is called rangani.
- In Punjabi it is called sham di sohnap, which means "evening beauty".
- In Indonesia it is called bunga pukul empat.
- In China it is called the "shower flower" (Chinese: 洗澡花; pinyin: xǐzǎo huā) or "rice boiling flower" (simplified Chinese: 煮饭花; traditional Chinese: 煮飯花; pinyin: zhǔfàn huā) because it is in bloom at the time of these activities.
- In Hong Kong it is known as "purple jasmine" (Chinese: 紫茉莉; pinyin: zǐ mòlì).
- The Turkish name is akşam sefası, which means "evening pleasure".
- In the Netherlands and in France the name of the plant is nachtschone and belle de nuit respectively meaning "beauty of the night".
- In Italy it is called bella di notte, which means "beautiful during night".
- In Iran it is called laleh abbasi (Persian: لاله عباسی).
- In Japan it is called oshiroi-bana (Japanese: オシロイバナ), as the white, powdery endosperm inside of mature seeds looks like oshiroi, the powder foundation used by geishas.
- In Israel it is named lilanit rav-gonit (Hebrew: לילנית רב-גונית), and more commonly called malkat halayla (Hebrew: מלכת הלילה), meaning "queen of the night".
- In Namibia it is called vieruurtjie ("four o'clock") as it starts to open at 16:00 until the morning.
- In Slovenia it is called nočna frajlica, meaning "night missy".
- In Serbia it is called noćurak (Serbian: ноћурак), sometimes noćna frajla (Serbian: ноћна фрајла).
- In Romania it is called frumoasa nopții, meaning "the beauty of the night", or also noptiță.
- In the Philippines it is called prinsesa ng gabi, meaning "princess of the night" or sometimes alas quatro, "at four o'clock".
- In Chile it is called putita, meaning "little hooker", because she is prettiest when her flowers come out at night.
- In Mexico it is called maravilla, meaning "marvel".
- In Malta it is called ħummejr.
- In Russia it is called zor'ka (Russian: зорька), meaning "dawning".
- In Syria it is called alshab alzarif (Arabic: الشاب الظريف).
- In Ukraine it is called nichna krasunya (Ukrainian: нічна красуня), meaning "night beauty".
- "Mirabilis jalapa". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 28 January 2016.
- "Investigations of the inheritance of flower variegation in Mirabilis jalapa L. 1. General introduction and 2. Inheritance of colour in uniformly coloured flowers. J.M.M. Engels, W.N.M. van Kester, C.J.T. Spitters, L. Vosselman, A.C. Zeven. Institute of Plant Breeding, Agricultural University, Wageningen." (PDF).
- J. Hutchinson, 1969. Evolution and phylogeny of flowering plants. London.
- "UCLA Mildred E. Mathias Botanical Garden". Botgard.ucla.edu. Retrieved 2012-07-31.
- 4 Oclock Flowers Archived July 17, 2016, at the Wayback Machine.
- Miko, I. Non-nuclear genes and their inheritance. Nature Education 1(1), (2008)
- Pigments of centrospermae—V. : Betaxanthins from Mirabilis jalapa L. M. Piattelli, L. Minale and R.A. Nicolaus, , Phytochemistry, 1965, Volume 4, Issue 6, Pages 817–823 (abstract)
- New Rotenoids from Roots of Mirabilis jalapa. Wang Yi-Fen, Chen Ji-Jun, Yang Yan, Zheng Yong-Tang, Tang Shao-Zong and Luo Shi-De, Helvetica Chimica Acta, August 2002, Volume 85, Issue 8, pages 2342–2348, doi:10.1002/1522-2675(200208)85:8<2342::AID-HLCA2342>3.0.CO;2-S
- An 8-hydroxyoctadeca-cis-11,14-dienoic acid from Mirabilis jalapa seed oil. Mohammad Shamim Ahmad, Abdul Rauf, Jamal Mustafa and Mohammad Osman Sheikh, Phytochemistry, 1984, Volume 23, Issue 10, Pages 2247–2249 (abstract)
- Constituents of Mirabilis jalapa. Siddiqui S., Siddiqui B.S., Adil Q. and Begum S., Fitoterapia, 1990, Volume 61, No. 5, page 471 (abstract)
- Three New Phenolic Compounds from a Manipulated Plant Cell Culture, Mirabilis jalapa. Shu-Wei Yang, Rosa Ubillas, James McAlpine, Angela Stafford , Dawn M. Ecker, M. Kelly Talbot and Bruce Rogers, J. Nat. Prod., 2001, volume 64, issue 3, pages 313–317, doi:10.1021/np0004092
- N-Caffeoylphenalkylamide derivatives as bacterial efflux pump inhibitors. Serge Michalet, Gilbert Cartier, Bruno David, Anne-Marie Mariotte, Marie-Geneviève Dijoux-franca, Glenn W. Kaatz, Michael Stavri and Simon Gibbons, Bioorganic & Medicinal Chemistry Letters, 15 March 2007, Volume 17, Issue 6, Pages 1755–1758 (abstract)
- "Mirabilis jalapa Marvel Of Peru PFAF Plant Database". Pfaf.org. Retrieved 2012-07-31.
- "h2g2 - Four O'Clocks - Night Blooming Beauties". Bbc.co.uk. 2002-08-20. Retrieved 2012-07-31.
- Growth responses and cadmium accumulation of Mirabilis jalapa L. under interaction between cadmium and phosphorus. Yu Z and Zhou Q, J Hazard Mater., 15 August 2009, volume 167, issues 1-3, pages 38-43, doi:10.1016/j.jhazmat.2008.12.082
- Correns, C. (1909). Vererbungsversuche mit blass (gelb) grünen und buntblättrigen Sippen bei Mirabilis, Urtica und Lunaria (in German). ZIAV 1.
- Pierce, B. (2005). Genetics: A Conceptual Approach (2nd ed.). New York, Freeman.
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