Pomegranate (Punica Granatum)

Background Information:

Punica granatum belongs to Lythraceae family of plants. It is a shrub to tree size plants that grow in Mediterranean climate. It is grown both as a fruit tree and as ornamental trees. Despite of its great adaptability, it is limited to warm areas as it can’t endure cold. It is thought that it is originated in ancient Persia and spread to rest of warm climate region from semi-arid to subtropical regions. This assumption is supported by the genetic diversity of Punica from Iran. More than 760 genotypes of Punica are reported from Iran. Beside Iran, Southeast Turkey and Mediterranean Basin are the areas that are well known for diversity of Punica from ancient times. Iran and Turkey is still famous for their production of Punica. In 2003, Iran produced 665,000 tons of Punica and Turkey is producing approximately 100,000 metric tons each year (Ercisli et al., 2007). Beside Iran and Turkey it is extensively produced in India, China, Russia, Japan and California of USA. Beside California, it is cultivated in Arizona, Georgia, Alabama, Nevada and Utah (Hodgson et al., 1917). The, Mediterranean countries ancient home of Punica are still producing Punica and include Egypt, Morocco, Tunisia and neighboring Spain. Punica has symbolic importance in cultures and religions originated in Middle East and Mediterranean region, like ancient Greece, ancient Persian cultures and Judaism, Christianity and Islam.

Areas of the world where the pomegranate is cultivated, shown by red dots
Its Persian name is “ انار” which is pronounced as “Annar” and it is known with its Persian name in South Asia and Central Asia specially in Urdu and Persian speaking areas. It is called “رمان “Arabic which is pronounced as “Romman”. Its scientific name, Punica granatum is derived from two Latin words, “pomum” meaning apple and “granatus” meaning “seeded”.
General Description:

Punica is shrub in colder regions but in tropical regions, it reaches to tree size of 10 to 15 feet in height. Trees are usually deciduous though some varieties are evergreen. It's flowering time ranges from spring to late summer which increases the success of pollination. Starting from visible part, leaves are usually opposite and sometimes alternate. The leaves are approximately half inch wide and 3 inches long and their shape is oblong and lanceolate. They are relatively thick, without glands, and cutin coating is visible by bright surfaces of leaves. Its leaves have entire margins.

The flowers are dominantly red however some varieties with red and white colors are reported from Java area of Indonesia ( John Uri Lloyd, 1897). The flowers are zygomorphic with five to seven thick and leathery adnate sepals and with same number of petals. Flowers are axillary, solitary or in small clusters, borne mainly at the tip of branches. On average flower size is half inch in size. Calyx are peculiarly orange or red in color, showy, tubular with five to seven sepals. Petals are crumpled and are white to scarlet red in color. Some flowers are steril and fall off early. The imperfect flowers have small pistils. Almost all flowers in ornamental types are steril (Hodgson et al., 1917). The fruit size varies greatly. Fruit weight ranged from 103.38 to 505.00 g and fruit volume from 99.41 to 547.88 cm3 (Vahid et al, 2009). The fruit is composed a thick leathery envelope, covering red juicy seeds that are separated in different chambers by white skinny layers.

General Classification:
Kingdom: Plantae, Division: Magnoliophyta
Class: Magnoliopsida Subclass: Rosidae
Order: Myrtales Family: Lythraceae
Genus: Punica Species: Punica granatum
Formerly Pomegranate was classified in a separate family Punicaceae that had a single Genus Punica. Genus Punica is now included in family Lythraceae. The closest to Punica granata is Crape myrtle trees in Lythraceae family which have identical leaves and sepals to P. granata. Order Myrtle contains 14 families of flowering plants.
Important Chemicals:
The bark of its roots tastes sour and turns water blue that precipitate in ferric salts. This is due of presence of 20 to 22% of tannic acid which is also called punicotannic acid referring to Punica. Beside fruits the rinds of fruits are also rich in punictannic acid containing almost 19%. Wild types have higher concentration of punicotannic acid than cultivars ones. Some flowers have tannic acid that taste bitter and turn saliva red. The root bark also contains several alkaloids. The most important one which posses anthelmintic properties are known as pelletierine. Pomegranate fruit is rich in vitamin-C and ellagic acid and it is famous for its rich anti-oxidant.
B-Sitosterol, Friedelin, D-Mannitol, Ursolic and Betulic acids were detected in the different parts of Punica granatum L (Ashraf et al. 1962?)

Following is the a table of nutrients content of Pomegranate taken from USDA National Nutrient Database for Standard Reference, Release 23 (2010),

Refuse: 44% (Skin and membrane)
Scientific Name: Punica granatum

Uses:
Cuisine and Fruit:
Aash (Persian soup) is one of the favorite dishes in Persian cuisine. Pomegranate Aash is one of many varieties of Aash series dishes. It is one of favorite fruit in Middle East, Mediterranean region, Central Asia and South Asia.
Tanning:
Moors is famous in tanning morocco by rind of Punica and it were Moors that introduced morocco to Spain. Beside Moors, Chinese and Japanese also use rind of Punica for tanning.
Dyeing:
Rind of Punica is used to dye fabrics and cloths in ancient India (and it is used but limited) and in Balkh area present day Afghanistan.
Medicinal Properties:
The anthelmintic properties of rind of pomegranate are found from ancient papyrus and it is used in this way in ancient Roman Empire (Hohn Uri, 1897). The combination of powdered rind of pomegranate and opium is used to control diarrhea in home remedies.
Other Medicinal Properties:
Asharf (Ashraf et al, 1962?) tested on the effect of D-Mannitol extracted from different parts of pomegranate (bark of root, leaves and flower) and seed oils and on mice rabbits to see their effect. Following is the summary of their experiments,
“Biological testing of the various extracts of the leaves, seeds, root and stem bark revealed their hypotensive, antispasmodic and anthelmintic effects. D-Mannitol was found to possess some anthelmintie properties and possible constipating value. Hormonal experiments on the oil showed that it has an oestrogenic activity but is devoid of any androgenic effect.”

Sensitivity:

As Punica granatum is native in semi-arid tropical region so it is really sensitive to frost, especially early frost in winter and spring. So, it is needed to save the plant from frost and too much humidity. Another aspect that should be cared is winter pruning. As plant grow vigorously when climate is suitable so pruning in winter is necessary to keep plant in shape and also having more fruit bearing branches.

Several pests have reported from California State of US includes, flat mite (Brevipalpus lewisi), Omnivorous leafroller (Platynola stultana), western leaf-footed plant bug, Comstock mealybug and Root-knot nematode. Besides, its fruits are damaged by heart rot as a result of Alternaria fungus infection.

References:

Anonymous, 2003. Area under cultivation and production of selected perennial crops. Iran Statistical Year Book 2003. Statistical Center of Iran.

A. SHARAF, M. ]3. E. FAYEZ & S. A. R. NEGI, PHARMACOLOGICAL PROPERTIES OF PUNICA GRANATUM L. Research Units of Pharmacology and Natural Products, National Research Centre, Cairo, U.A.R., 1962?

Ercisli S, Agar G, Orhan E, Yildirim N, Hizarci Y (2007). Interspecific variability of RAPD and fatty acid composition of some pomegranate cultivars (Punica granatum L) growing in Southern Anatolia Region in Turkey. Biochem. Syst. Ecol. 35: 764-769.

Graham, S. A., Thorne & Reveal (May 1998). "Validation of subfamily names in Lythraceae". Taxon 47 (2): 435–436.

Robert W. Hodgson, "The pomegranate", University of California Press, Berkeley, Bulletin No. 276, January 1917. P, 163, 169,

Vahid Akbarpour, Khodayar Hemmati and Mehdi Sharifani, Physical and Chemical Properties of Pomegranate (Punica granatum L.) Fruit in Maturation Stage, American-Eurasian J. Agric. & Environ. Sci., 6 (4): 411-416, 2009