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Nga-nga
BETEL NUT CHEWING
The Ancient Buzz

Common names  
ASSAM: Pan tamul. SINHALA: Bulath
CHAMORRO: Mamaon. TAGALOG: Buyo, Nga-nga.
HINDI: Paan. TAMIL: Vettila
INDIA: Tambula. TETUM: Mama.
MALAY: Sirih. THAI: Plu.
MALAYALAM: Vettila. TOKODEDE: Mam.
MALDIVES: Dhu'fuň. VIETNAM: Trau.
NEPALI: Supadi. VISAYAS: Maman, Mamon, Mama-n.

General info
Betel nut chewing is a masticatory indulgence—ancient, ritualistic, and medicinal. It is reported to be the fourth most commonly used psychoactive substance in the world, used by 10 to 25% of the world population. Although it is uncertain when the areca nut and betel leaf was first combined into a psychoactive concoction, Betel chewing is a practice of great antiquity —anthropological findings date it as far back as 6500 BC. In the Indian Subcontinent, the chewing of areca nut and betel leaf dates back to the pre-Vedic period. (3) In the Philippines, a human skeleton with blackened teeth was reported, dated back to 2600 BC. It has been reported in many ancient cultures, with references in Chinese, Islamic, Indian, and Greek literature. Betel chewing was an established practice among Indians for the past 2000 years, a popular activity most Asian countries, and introduced to the Middle East, some European and African countries by Asian migrants.

  The quid is a combination of natural ingredients that has been providing an ancient psycoactive buzz. The addition of chewing tobacco gives it an added kick. It is habituating and addicting, and associated with withdrawals. Capsulizing the ingredients will certainly make it illegal and banned. But in its quid form, it's all natural, all legal.  
     

Betel chewing colors countles cultures not just with red spittle. Betel chewing and its ingredients continue to be auspicious in many religious, traditional and marriage rituals. In India, betel chewing was considered one of the eight cardinal pleasures, equal to food, sex, music, sleep, incense, flowers and perfume in its life enhancing qualities. (2) In Vietnam, the areca nut and betel leaf are important symbols of love and marriage, and used in wedding ceremonies. (3) The betel leaf is an essential ingredient in many Hindu functions and festivals. In Malay culture and tradition, a tray of nut and leaves are served to welcome guests. In the Philippines, betel nut figures often in tribal rituals of courtship and marriage. Although there has been cultural rejection of betel use—Islam, for one—most cultures continue to embrace its use, by both men and women, of all ages and classes.

Nga-nga: Betel chewing in the Philippines
- In the Philippines, betel chewing is referred to as nga-nga: nga-nga as the composite of ingredients, nag-nga-nga-nga as betel chewing.
- Betel chewing used to be prevalent in the Philippines, from the Cordillera mountains in the north to the Muslim communities in the south.
- Time was, nga-nga was an item of hospitality and friendship, a social lubricant proffered during social encounters, as tea, coffee or wine, or the marijuana joint in more recent times. In earlier Spanish times, the buyo was served in elegant plates or service sets for the indulgence of the burgis.
- In central or southern Mindanao, betel chewing is a ritualistic custom among the among the Maranao, Maguindanao, Bagobo and Tausug groups. 
- The essential ingredients are (1) the areca nut, the seed of the areca palm (Areca catechu). (2) betel leaves, which wraps the areca nut, and referred to by some as the "betel nut." (3) lime or apog, daubed on the betel leaf.
- Mascada, a plug of chewing tobacco, is a popular addition to the betel chew, providing an addition kick.


Betel Chew Ingredients
Buñga (Arecha catechu): Bunga (Areca catechu): The areca nut is not a true nut, but rather, a drupe. It is an essential ingredient, raw or dried, sliced, shredded or cut into pieces and chunam into burnt chalk, coral or sea shells (slaked lime) with a piece of sun dried tobacco for added kick. The nut yields tannin, gallic acid, a fix oil gum, a little terpineol, lignin, and three main alkaloids: arecoline, arcain, and guvacine. It also contains small amounts of pilocarpine and muscarine. The active ingredient in areca is arecoline, constituting about 0.25%. Arecoline is a stimulant, stimulating the parasympathetic nervous system, causing pupil contraction, increasing secretion of tears and salivation.
Ikmo / Betel / Piper betel: Piper betel, the essential leaf ingredient, yields a volatile oil similar to aromatic eugenol found in the oil of cloves. The leaves are usually daubed with lime, then packed with slices of areca nut inside, and folded in a variety of ways, then chewed until it reddens the mouth.
Apog / Lime: Lime, the third ingredient, is a catalyst—powdered (calcium oxide) or paste (calcium hydroxide), made from kiln-baked seashells; it keeps the active ingredient in freebase or alkaline form, enabling it to enter the bloodstream via sublingual absorption. Beside seashells, mollusk (snails, mussels, fresh water shellfish) and coral are sources of lime in island areas.
Additives
Tobacco / Mascada: A piece of sundried tobacco is used for added "kick."
• Other additives according to region or preferences: Fennel, turmeric, cumin, melon and cucumber seed, tamarind juice, coriander, nutmeg, ginger, cardamom, cinnamon, cloves and grated copra are added as desired.
• In India, menthol, rose water and mint essences are added.
• Substitute: In the Philippines, when the areca nut is not available, the fleshy seed of Buñga de Jolo
(Manila palm, Adonidia merrillii) is used as substitute, although inferior as a masticatory.

The traditional method of making the betel quid
• In South-East Asia, the leaf is daubed with lime paste and topped with thin slices of an areca-nut; then the leaf is folded, like wrapping a present, to the desired shape and size. Finally, the wad is placed between the teeth and the cheek and pressed with the tongue to allow sucking and chewing. Sometimes it is held in the mouth for hours; others sleep with it. The interaction of the ingredients during chewing produces a red-coloured saliva. Most of the betel juice is spat out. as red spittle. The tell-tale residue looks like splotches of dried blood on the ground, often mistaken as globs of tuberculous phlegm.

Misnomers
• The betel chew is not really chewed; rather, it is sucked, inserted between the cheek and gum to soak, eliciting salivation.
• "Betel nut" is a misnomer; the main ingredient in the betel chew is the areca nut, often wrapped in betel leaf, with lime added as catalyst.

Constituents
• Specific areca alkaloids act as competitive inhibitors of γ-aminobutyric acid receptors in the brain, cardiovascular system, and pancreas, which may promote one's appetite or altered insulin secretion.
Seeds of areca contain catechin, tannins (15%), gallic acid, fat, gum and alkaloids like arecoline (0.07%) and arecaine (1%). Arecaidine, guvacoline, guvacine and choline are present in trace amount. Arecoline is the major alkaloid.

Properties
• Sanskrit writing describes 12 desirable qualities: pungency, bitter, sweet, spicy, salty, astringent, it expels wind, kills worms, removes phlegm, eradicates odors, purifies all organs of the body and even induces passion! (2)
• Father of Indian Medicine, Sushruta in the first century AD said betel chewing tends to "cleanse the mouth, imparts a sweet aroma to it, enhance its beauty, cleanse and strengthen the voice, tongue, teeth, jaws and sense organs and acts as a general safeguard against diseases.
(2)
• In Ayurveda, considered carminative, stimulant, astringent, aphrodisiac, digestive, and cosmetic.

Effects
• Generally chewed for its stimulant effect. Users may describe a warm body sensation with heightened alertness, sweating, palpitations, and increased capacity for work.
• Generally reported to have good effects: well being, good humor, excitation and feeling of energy, decreasing hunger, assuaging pain, without impairment of consciousness.
(2)
• Some users describe three delightful effects: the exhilarating life, the mysterious indescribable flavor, and the compelling salivation. (2)
• Unpleasant acute effects have been reported: palpitations, exacerbation of asthma, vomiting, hypertension.
• It produces a feeling of euphoria and acts as a stimulant. On an empty stomach, it can cause a decrease in appetite and diarrhea.
• Although there is little documented evidence of significant psychoactive substances, it is believed to be psychologically addictive. However, there is a dearth of reports on physical withdrawal symptoms.
• Effects are considered habit related and dose-dependent. Although arecoline is thought responsible for several effects, data suggest a role played by sympathetic activation. (21)

Uses
Edibiity
- The shhot is edible.
- Seed chewed as areca quid.
Folkloric
- The Igorots chew the betel to stave off hunger and tiredness.
- Used to help strengthen the teeth.
- Regular chewing believed to reduce cavities.
- Used for aphrodisiac effects in some Quezon rural areas. (See study) (27)
- U
sed in the preparation of Chinese and Ayurvedic medicines.
- Powdered areca nut is used as constituent of tooth powders. Decoction of powdered areca nut used for tapeworms and other intestinal parasites.
(3)
- In
India, betel is used to cast out worms. In Ayurvedic medicine, chewing areca nut and betel leaf is used for halitosis. Also used as an aphrodisiac, for constipation and indigestion, lactation aid, and as a diuretic.
- In
Indonesia, betel leaves used for vaginal discharge, and also in post-partum baths to shrink the vaginal canal. (8)
- In
Papua New Guinea, where a 2010 survey reported almost half of the population chew betel nut every day, it is used as an appetite suppressant, addictive pick-me-upper, and palate cleanser.
- In Vietnam, used to make the mouth fragrant, decrease bad tempers, and assist in digestion.

Others
- In veterinary medicine, used as purgative and for deworming.
- In England, around 1842, reported to be used in toothpaste with the belief that betel strengthens enamel and removes tartar.
(9)
- Chewing-induced red stained lips in women considered marks of beauty.

Studies
• Oral Cancer / Smoking, Alcohol, and Betel Quid:
Results of multivariate logistic regression found that those who smoked, consumed alcohol, and chewed betel quid on a regular basis were more likely to develop cancer, and suggests regular oral screening for potential oral cancer.
(4)
Betel quid chewing responsible for half of oral cancer cases in India:
Study reports eliminating consumption of betel quid in India could halve the country's oral cancer burden, preventing more than 37,000 cases a year. A higher risk of buccal mucosa and cheek cancer was noted in betel quid with tobacco group. Risk of cancer was higher among women.
(5)
Betel Quid Dependence / Pre-Neoplastic Risks:
Study across six Asian samples showed a 12-month prevalence of dependence of 2.8-39.2%., and 20-9-99.6% of those who chewed betel-quid were betel-quid dependent. Those with betel quid dependence had higher pre-neoplastic risks.
(6)
Betel and Human Papilloma Virus:
Studies have found an association between use of betel and infection with human papilloma virus, which may exacerbate the nut's carcinogenic properties.
(7)
Areca Nut Chewing and Metabolic Syndrome: A study of 1,466 aboriginal subjects of Southern Taiwan, 30-95 years of age, showed that chronic BQ chewing is an independent contributor of metabolic syndrome. TBF-α, leptin, and leukocyte count are involved in BQ chewing-related metabolic derangements. (12)
Diabetogenic / Nut: Studies showed that chewing betel nut is associated with newly diagnosed type 2 diabetes mellitus, supporting the suggestion that the habit is diabetogenic. Chewers among the diabetic patients were younger, more obese and had higher prevalence of parental diabetes than never-chewers (all p values < 0.001). (13)
Hypertension in Betel Nut Chewing T2 Diabetic Patients: Betel nut chewing was significantly associated with hypertension in Taiwanese patients with type 2 diabetes mellitus and the association was stronger in women. (14)
Cirrhosis and Hepatocellular Cancer Risk in Betel Chewers: Study showed an increased risk of cirrhosis and hepatocellular cancer among betel chewers free of hepatitis B/C infections. Risks were synergistically additive to those of hepatitis B/C infections. (15)
Central and Autonomic Nervous System Effects: Betel chewing produces complex reactions and interactions. In the presence of lime, arecoline and guvacoline in Areca nut are hydrolyzed into arecaidine and guvacine, which are strong inhibitors of GABA uptake. Piper betle flower of leaf contains aromatic phenolic compounds which stimulate release of catecholamines inn vitro. Thus BC can affect parasympathetic, GABAnergic, and sympathetic functions. BC also increases heart rate, blood pressure, sweating and body temperature. All these suggest BC affects the central and autonomic nervous systems. (16)
Anti-Schizophrenic Effects: Study results indicate that betel chewing may exert a beneficial effect on the primary symptoms of schizophrenia, attributed to the pharmacologic effect of the abundant betel nut alkaloid, arecoline. (17) Male high-consumption betel chewers had significantly milder positive symptoms than low-consumption chewers over 1 year. Betel chewing was associated with tobacco use but not with cannabis or alcohol. The findings have broader implications for the theory of muscarinic neurophysiology in schizophrenia. (18)
Cardiovascular Risks: Betel nut chewing was independently associated with greater risk of cardiovascular disease and all-cause mortality in Taiwanese men. Regular screening for betel nut chewing may help prevent excess deaths in the future. (19) Although Doppler studies showed intracranial cerebral hemodynamics is not affected during betel chewing, inotropic and chronotropic effect to the heart from betel chewing is probably an unfavorable risk for patients with ischemic heart disease. (22)
Betel Chewing and Subclinical Ischemic Heart Disease in Diabetic Patients: Study showed betel nut chewing is significantly associated with increased risk of subclinical ischemic heart disease in diabetic patients. Betel nut chewers were younger with a higher prevalence of smoking, higher body mass index, and poorer glycemic control. (20)
Relation between Betel Quid Chewing and Cigarette Smoking: Study investigated the behavioural and mortality relations between BQ chewing and cigarette smoking. Results suggest the serious health consequences suffered by BQ chewers were the results of combined effects of smoking and chewing. Study suggests BQ chewing should not be considered an isolated issue, but viewed conjointly with cigarette smoking. (23)
Risk for Esophageal Cancer: Among 104 cases of squamous-cell oesophageal carcinoma patients and 277 controls in Taiwan, after adjusting for cigarette smoking, alcohol consumption, and other confounders, study found that subjects who chewed from 1 to 495 betel-year and more than 495 betel years (about 20 betel quid per day for 20 years) had 3.6-fold and 9.2-fold risk respectively, of developing oesophageal cancer, compared to those who did not chew betel. (24)
Risk for Oral Submucous Fibrosis: Oral submucous fibrosis (OSMF) is a chronic, insidious, disabling potentially malignant condition of the oral mucosa seen predominantly in south and SE Asia. The study showed a strong association of BQ chewing (including tobacco as an ingredient) with the causation of OSMF. (25)
Long-Term GI Effects: Study in rats showed prolonged chewing of areca nut caused significant alterations in intestinal epithelial cell line functions and could lead to malabsorption of nutrients. (26)
Aphrodisiac Effect: Study evaluated the aphrodisiac effect of A. catechu along with another plant, Pedalium murex, used in herbal aphrodisiac formulations. In the rat study, there as significant increase in mounting frequency, intromission frequency and latency, and significant reduction in mounting latency and post-ejaculatory interval. Results suggest an aphrodisiac effect, with no conspicuous adverse effects. (27)
Betel Nut Chewing during Pregnancy / Papua New Guinea: A cross-sectional survey of 310 pregnant women in Madang Province, Papua New Guinea detailed demographic data, chewing habits, potential addictions, among others. Among pregnant women, 94% regularly chew betel nut, 9% smoke, and 1% used alcohol. The main reason for use in pregnancy was to prevent morning sickness (28%), to prevent a smelly mouth (26%), habit (20%), addiction (10%). Primigravidity, betel chewing, and a low BMI had a statistically significant impact on birth weight reduction. 80% of the women thought betel chewing did not have any effect on the fetus. (28)
Hypercalcemia / Metabolic Alkalosis: An in vitro study evaluated why only a small proportion of individuals who ingest alkaline calcium salts develop hypercalcemia, hypokalemia and metabolic alkalosis. The relatively greater availability of ionized calcium than inorganic phosphorus in the intestinal lumen could have enhanced dietary calcium absorption. (29)
Systemic Inflammation in Chewers / Effect of Tobacco Additives: Study evaluated the incidence of systemic inflammation among areca nut chewers and healthy controls. Results showed areca nut chewing has a significant association with systemic inflammation. Areca nut chewers with tobacco additives were two times more likely to have elevated CRP compared to raw areca nut users. (30)
Chewing Patterns and Adiposity Measures: In the Mariana Islands, study showed Class 1 chewing (chewing areca nut without tobacco) is associated with high central adiposity among males, but not among females. (31)

Availability
Betel chew ingredients in local markets.
Often available in the Quiapo church Friday market.

August 2014
Last Updated September 2014


Photo / Leaf & Fruit © Godofredo Stuart / StuartXchange
OTHER IMAGE SOURCE: Photo: © VLAD SOKHIN / An 8-year-old boy from Messi village in New Ireland Province chews betel nut./ Chewing / Off Their Nut In PNG / Project PNG
OTHER IMAGE SOURCE: Photo / A jar of lime powder (kambang); a bean-like green stick called mustard (daka) and green betel nuts (buai) / © Making Lime for Betelnut Chewing in M'Buke, Manus, PNG / click on image to go to source page / WWF CORAL TRIANGLE BLOG

Additional Sources and Suggested Readings
(1)
Making Lime for Betelnut Chewing in M'Buke, Manus, PNG / WWW Coral Triangle Photo
(2)
A cardinal pleasure—Betel chewing / A. C. B. Pethiyagoda / Saturday Magazine
(3)
Areca nut / Wikipedia
(4)
Smoking, alcohol, and betel quid and oral cancer: a prospective cohort study. / Lin WJ1, Jiang RS, Wu SH, Chen FJ, Liu SA. / J Oncol. 2011;2011:525976. / doi: 10.1155/2011/525976. Epub 2011 Mar 17.
(5)
Betel quid chewing is responsible for half of oral cancer cases in India, finds study / Cheryl Travasso / BMJ 2013; 347/ doi: http://dx.doi.org/10.1136/bmj.f7536
(6)
Betel-quid dependence and oral potentially malignant disorders in six Asian countries / Chien-Hung Lee, Albert Min-Shan Ko, Cheng-Fang Yen, Koung-Shing Chu, Yi-Jun Gao, Saman Warnakulasuriya, Sunarjo, Salah Osman Ibrahim, Rosnah Binti Zain, Walter K. Patrick and Ying-Chin Ko / The British Journal of Psychiatry (2012) 201, 383–391 / doi: 10.1192/bjp.bp.111.107961
(7)
The Betel Nut: An Emerging Public Health Threat? / S. Van McCrary, Health Law & Policy Institute
(8)
Betel / Wikipedia
(9)
Betel chewing / Suchitthra Vasu / 1999-05-05 / National Library Board Singapore
(10)
Betel Chewing in South-east Asia / Dawn F. Rooney / Paper was prepared for the Centre National de la Recherche Scientifique (CNRS) in Lyon France, August 1995
(11)
Betel Chewing in the Philippines / Cynthia Ongpin Valdes / Arts of Asia September/ October 2004 issue
(12)
Areca Nut Chewing Is Associated With Metabolic Syndrome / Role of tumor necrosis factor-α, leptin, and white blood cell count in betel nut chewing–related metabolic derangements / Fu-Mei Chung, MS, Dao-Ming Chang, MD, Miao-Pei Chen, MS, Jack C.-R. Tsai, MD, MPH, Yi-Hsin Yang, PHD, Tien-Yu Shieh, PHD, Shyi-Jang Shin, MD, PHD, Tony Hsiu-Hsi Chen, PHD, Tong-Yuan Tai, MD, PHD and Yau-Jiunn Lee, MD, PHD / Diabetes Care July 2006 vol. 29 no. 7 1714 / doi: 10.2337/dc06-0628
(13)
Betel nut chewing and incidence of newly diagnosed type 2 diabetes mellitus in Taiwan. / Chin-Hsiao Tseng / BMC Res Notes, 2010; 3:228
(14)
Betel Nut Chewing Is Associated with Hypertension in Taiwanese Type 2 Diabetic Patients / Chin-Hsiao Tseng / Hypertension Research (2008) 31, 417–423 / doi:10.1291/hypres.31.417
(15)
Impact of chewing betel-nut (Areca catechu) on liver cirrhosis and hepatocellular carcinoma-: a population-based study from an area with a high prevalence of hepatitis B and C infections / Grace Hui-Min Wu, Barbara J Boucher et al / Public Health Nutrition: 12(1), 129–135 doi:10.1017/S1368980008002073
(16)
Effects of Betel chewing on the central and autonomic nervous systems. / Chu NS. / J Biomed Sci. 2001 May-Jun;8(3):229-36.
(17)
Effects of cheweing betel nut on the symptoms of people with schizophrenia in Palau, Micronesia / Roger J Sullivan et al / British Journ of Psychiatry, 2000, 177, 174-178
(18)
The Effects of an Indigenous Muscarinic Drug, Betel Nut (Areca catechu), on the Symptoms of Schizophrenia: A Longitudinal Study in Palau, Micronesia / Roger J. Sullivan, Ph.D., Sylvia Andres et al / Am J Psychiatry 2007; 164:670–673
(19)
Betel nut chewing is associated with increased risk of cardiovascular disease and all-cause mortality in Taiwanese men / Wen-Yuan Lin, Tai-Yuan Chiu, Long-Teng Lee, Cheng-Chieh Lin, Chih-Yang Huang, and Kuo-Chin Huang / The American Journal of Clinical Nutrition - Am J Clin Nutr May 2008 vol. 87 no. 5 1204-1211
(20)
Betel Nut Chewing and Subclinical Ischemic Heart Disease in Diabetic Patients / Chin-Hsiao Tseng / Cardiology Research and Practice, Volume 2011 (2011) / http://dx.doi.org/10.4061/2011/451489

(21)
ARECA NUT SYMPOSIUM Neurological aspects of areca and betel chewing / NAI-SHIN CHU / Addiction Biology (2002) 7, 111-114
(22)
Cerebral Hemodynamic Responses to Betel Chewing: A Doppler Study / Lin, Shinn-Kuang; Chang, Yeu-Jhy; Ryu, Shan-Jin; Chu, Nai-Shin / Clinical Neuropharmacology, September/October 2002 - Volume 25 - Issue 5 - pp 244-250
(23)
Uncovering the relation between betel quid chewing and cigarette smoking in Taiwan / C P Wen, S P Tsai, T Y Cheng, C-J Chen, D T Levy, H-J Yang, M P Eriksen / Tob Control 2005;14:i16-i22 / doi:10.1136/tc.2004.008003
(24)
Risk of betel chewing for oesophageal cancer in Taiwan / M-T Wu, Y-C Lee, C-J Chen, P-W Yang, C-J Lee, D-C Wu, H-K Hsu, C-K Ho, E-L Kao and J-M Lee / British Journal of Cancer (2001) 85(5), 658–660 / doi: 10.1054/ bjoc.2001.1927
(25)
Effect of betel chewing, tobacco smoking and alcohol consumption on oral submucous fibrosis: a case-control study in Sri Lanka. / Ariyawardana A, Athukorala AD, Arulanandam A. / J Oral Pathol Med. 2006 Apr;35(4):197-201.
(26)
Effect of betel/areca nut (Areca catechu) extracts on intestinal epithelial cell lining / Kumar M, Kannan A, Upreti RK. / Vet Hum Toxicol. 2000 Oct;42(5):257-60
(27)
Aphrodisiac Effect of Areca catechu L. and Pedalium murex in Rats / Reena R. Nelson Anthikat, Antonysamy Micheal, and Savarimuthu Ignacimuthu. / Journal of Men's Health. June 2013, 10(2): 65-70. / doi:10.1016/j.jomh.2012.07.003.
(28)
Betel nut chewing during pregnancy, Madang province, Papua New Guinea / M. Senna, F. Baiwoga, J. Winmaia, I. Muellerb, S. Rogersonc, N. Senna / Drug and Alcohol Dependence, Volume 105, Issues 1–2, 1 November 2009, Pages 126–131
(29)
Hypercalcaemia and metabolic alkalosis with betel nut chewing: emphasis on its integrative pathophysiology /
Shih‐Hua Lin, Yuh‐Feng Lin, Surinder Cheema‐Dhadli, Mogamat Razeen Davids and Mitchell L. Halperin / Nephrol. Dial. Transplant. (2002) 17 (5): 708-714. / doi: 10.1093/ndt/17.5.708
(30)
Areca nut chewing and systemic inflammation: evidence of a common pathway for systemic diseases /
Kashif Shafique*, Saira Saeed Mirza, Priya Vart, Abdul Rauf Memon, Moin Islam Arain, Muhammad Farooq Tareen and Zia Ul Haq / Journal of Inflammation 2012, 9:22 / doi:10.1186/1476-9255-9-22
(31)
Pattern of areca (betel) nut chewing and obesity measure in Guam and Saipan, Mariana Islands / Yvette C Paulino, PhD, Eric Hurwitz, Lynne Wilkens, Rachel Novotny, Mary Jane Miller, Katrina Quinata / 20th IEA World Congress of Epidemiology, August 2014, Anchorage, Alaska USA

Also check out: Bunga and Ikmo for specific and related studies on Areca catechu and Piper betel.
It is not uncommon for links on studies/sources to change. Copying and pasting the information on the search window or using the DOI (if available) will often redirect to the new link page.

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