Gen info
- Eugenia is a genus of over 1000 species occurring in tropical and subtropical rainforests.
- Eugenia reinwardtiana is a shrub or small tree in the family Myrtaceae, native to tropical forests in Indonesia, the Australian state of Queensland, and many Pacific Islands. (2)
- Etymology: The genus name Eugenia honors Prince Eugene of Savoy, France (1663-1736), a patron of botany. The species epithet is named after Caspar Georg Carl Reinwardt (1773-1854), a director of the the Leiden Botanic Garden. (3)

Botany
• Growth form: Shrub to small-sized tree, able to grow up to about 2 - 5 m tall. Foliage: Green and shiny leaves, elliptic, measuring about 2 - 9 cm long and 1 - 5 cm wide, petiole measuring about 0.1 - 0.6 cm long. Flowers: Small, cream white flowers usually in axillary positions.  Fruit: A red-colored drupe and globular in shape. (Flora & Fauna Web)

•  Bushy to sprawling shrub to 2m. Leaves: Opposite, wide-oval, to 8x6cm, glossy green, edge smooth and strongly down-curved, base round, tip round; stalk 4mm. Flowers: Axillary, 1-2; 2cm; petals 4, white, wide-oval, tip round; stamens many, ~100, 5mmL, white. Fruit: Round, 2cm, ripen bright red, fleshy, with 1-2 large seeds; tip with sepals persistent. (9)

Distribution
- Introduced.
- Cultivated.
- Native to Borneo, Caroline Is., Cook Is., Fiji, Hawaii, Jawa, Lesser Sunda Is., Maluku, Marianas, Marquesas, New Guinea, Niue, Pitcairn Is., Queensland, Samoa, Society Is., Tonga, Tuamotu, Tubuai Is., Vanuatu, Western Australia. (1)

Constituents
- Study evaluated two chemotypes E. reinwardtiana leaves for essential oil. Chemotype 1 with 0.2% yield, w/w, dry weight contained major amounts of α-pinene (10-26%), limonene (1-15%),
ß-caryophyllene (0.7-11%), α-humulene (0.9-16%) and bicyclogermacrene (1-23%). Chemotype 2 isolated in 0.4-0.6%, w/w, dry weight, contained α-pinene (tr-8.5%), ß-caryophyllene (12-27%), and
α-humulene (1-17%) as major terpenes, along with the novel aliphatic diketone, 2-butyl-2,4,4-trimethyl-5-methoxycyclohex-5-en-1,3-dione (18–33%). (4)
- HPLC-PDA quantification of fruit for common phenolics yielded: Cyanidin 3-glc (1.42 mg/g); myricetin 0.01 ± 0.7 × 103; quercetin 0.03x103, quercetrin 0.05x103, rutin 0.4x103, with no detectable ellagic acid. (5)

Properties
- Species is susceptible to myrtle rust (Austropuccinia psidii).
- Studies have suggested antimicrobial, antioxidant properties.

Parts used
Leaves, fruits.

Uses
Edibility
- Fruit is edible, mildly sweet; usually eaten out-of-hand. Also used to flavor drinks and candies, or to make preserves. (2)
Folkloric
- No reported folkloric medicinal use in the Philippines.
- In Palau, young leaves used to treat chest pains. For gonorrhea, ten young leaves are mixed with ten young leaves of Piper betle and eaten raw. (6)
Others
- Horticulture: Well-suited for amenity horticulture in the tropics. (2)
- Fuel: Wood is hard and makes for excellent firewood.
- Crafts: Used to make coconut husking stakes and to make rice-pounding pestles.

Studies
• Antioxidant / Antiradical Phenolic Constituents: Study evaluated E. reinwardtiana ripe fruits for antiradical activity, total phenolic content (TPC), and total anthocyanin content (TAC). Results showed antiradical DPPH activity with IC50 of 110 µg/mL,  TAC of 0.08 mg C3G/g d.w., and TPC pf 9.25 mg GAE/g dry weight. (5)
• Silver Nanoparticles / Antimicrobial / Food Packing Application: Study reports on the green synthesis of silver nanoparticles using leaves extract of E. reinwardtiana. The nanoparticles were further used to prepare nanocomposites with TOPAS to explore potential for food packaging applications. Mechanical testing, antimicrobial testing, and water vapor permeability tests were carried out to evaluate the properties of nanocomposites films essential for packaging applications. The nanocomposite films demonstrated considerable increment with addition of AgNPs. The nanocomposite films showed enhanced antimicrobial behavior compared with pure TOPAS films. Results indicated potential of nanocomposite films for use in food packing applications. (7)

Availability
- Cultivated.
- Seeds and seedlings in the cybermarket. (RFT).

Additional Sources and Suggested Readings
(1)
Eugenia reinwardtiana / KEW: Plants of the World Online
(2)
Eugenia reinwardtiana / Wikipedia
(3)
Eugenia reinwardtiana / National Parks: FLORA & FAUNA WEB
(4)
The Leaf Essential Oil of Eugenia reinwardtiana Growing in Australia / Joseph J Brophy, John R Clarkson, David N Leach et al / Natural Product Communications / DOI: 10.1177/1934578X1501000931
(5)
Quantitative analysis of antiradical phenolic constituents from fourteen edible Myrtaceae fruits / Kurt A Reynertson, Hui Yang, Bei Jiang, Margaret J Basile, Edward J Kennelly / Food Chem., 2008; 109(4): pp 883-890 / DOI: 10.1016/j.foodchem.2008.01.021
(6)
THE PALAUAN AND YAP MEDICINAL PLANT STUDIES OF MASAYOSHI OKABE, 1941-1943 / Robert A Defillips, Shirley L Maina, Leslie A Pray / ATOLL RESEARCH BULLETIN No.317
(7)
Preparation and Investigation of Ag Nanoparticles /TOPAS Nanocomposite Films for Packaging Applications / Hareem Zainab,  Zakir Hussain, Ahmad N Khan, Usman Liaqat, Muhammad B K Niazi, Tahir A Baig / Current Nanoscience, 2018; 14(6): pp 538-544 / pISSN: 1573-4137 / eISSN: 1875-6786 / DOI: 10.2174/1573413714666180717114523
(8)
Eugenia reinwardtiana / Ken Fern / Useful Tropical Plants
(9)
Reinwardt's cherry / Cook Islands Biodiversity Database

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