Date palm, תָּמָר, Phoenix dactylifera

Kingdom: Plantae

Division: Angiospermae

Class: Monocotyledoneae

Order: Arecales

Family: Arecaceae

Genus: Phoenix

Species: Phoenix dactylifera

Commonly known as the date palm, the Phoenix dactylifera (Latin for ‘date-bearing’ [Liddell & Scott 1861]) is a flowering plant species of the Arecaceae family, native to tropical and subtropical areas of Asia and Africa. A flowering monocotyledon (Krueger 2021), its seeds contain an embryo with only one embryonic leaf, also called a cotyledon—other flowering plants being dicotyledons, since they have two cotyledons. Most monocotyledons are herbaceous, possessing little or no woody tissue and customarily lasting over one growing season. Only a small number being trees, the P. dactylifera is thus unusual. Monocotyledon trees exhibit unique anatomical characteristics: not creating growth rings, it is difficult to estimate their age (Zaid & de Wet 2002), for example. Slow-growing, they can live over 100 years and reach 30m in height (Hodel, Johnson, & Nixon 2007).

The date palm is a slow-growing tree that can reach over 100 years of age (Hodel et al. 2007). In Israel, its fruit begin forming around June, customarily ripening between August and October. The flowers bloom between the end of March and the beginning of June (www.flora.org.il; Feldman 1956, 43–48).

Palm-shaped leaves. Members of the Arecaceae family have large evergreenleaves that are either palmate (“fan-leaved”) or pinnate (“feather-leaved”), arranged spirally at the top of the stem. The only genus with pinnate leaves, the Phoenixgenus is unique among its subfamily (Riffle & Craft 2003).

Image was taken from Johnson (2011).

Withering due to Locusts. P. dactylifera leaves are particularly vulnerable to two locust species—the desert locust (Schistocerca gregaria) and the Egyptian locust (Anacridium aegyptium). Both these species inhabit habitats similar to those of the Phoenix dactylifera (El-Shafie 2012).

Tall, Erect Trees that Can Be Climbed. The Phoenix dactylifera has a non-branching trunk that can reach 20m in height (Loutfi & El Hadrami 2005; Zaid & de Wet 2002). Pollination is essential for the formation of fruits—an important human commodity. Although this process occurs naturally via the wind, techniques were invented early on to make it more efficient and economical for growers. Enabling farmers to scale the trees in order to collect the pollen from the male trees and transfer it to the female trees, these remain prevalent today (Abu-Zahra & Shatnawi 2019).

Blossoming and Flourishing Periods. An evergreen, the date palm blooms in the spring, and the fruit are being harvested from the end of the summer until mid-fall (for more specific information see life history section; (flora.org.il).

Grows in the Wild between Egypt and Israel, in the Ephraimite hill-country, and Close to Springs. The first signs of date-palm domestication in the Levant area date to ca. 6,500 BCE (Zohary et al. 2012)—approximately 5,000 years prior to the assumed “biblical period.” Those referred to in the biblical text were thus presumably domesticated rather than wild. Growing naturally in arid areas close to springs and/or easily accessible groundwater and requiring high temperatures (www.wildflowers.co.il), the date palm is found principally in Israel in oases—the Arava, Dead Sea Valley, and Lower Jordan Valley. Although less common on high places, it is also occasionally found in the Samarian and Judean mountains and Negev hills (www.flora.org.il; www.wildflowers.co.il). According to Judges, Deborah used to sit under the “tomer of Deborah” between Ramah and Bethel in the Ephraimite hill country (Judg 4:5). The Ephraimites settling in some parts of the Samarian mountains, date palms may have been native to this area (or transplanted in an early period), despite this not being their optimal habitat. Not many date palms were growing in the mountainous area, perhaps because there they hardly produce fruits, if at all. Hence, mountainous P. dactylifera were mostly used for their shade, wood and other tree parts (Halperin & Arnon, 1976).

Multiple Flowers and Clustered Fruits. The date palm’s male and female flowers grow in clusters (inflorescences). Known as spadices or spikes, these consists of a central stem (rachis) and several strands or spikelets (usually 50–150 lateral branches) (Zaid & de Wet 2002). Each of the latter carry between 8,000 and 10,000 female flowers and even more male flowers (Chandler 1958). The fruit develops from a single flower, thus being organized in clusters like the flowers, the species name dactylifera—signifying “finger-bearing”— referring to the shape of the fruit (Friedman et al. 2010).

Seed dispersal. Containing high carbohydrate levels, date palm fruits form a major part of the diet of resident and migratory bird species and fruit bats as well as a major agricultural crop in the (semi-)arid zone of North Africa and the Middle East. Studies evince dispersal distances ranging from dozens of meters to ca. 50km, carried by diverse bird species and terrestrial animals (primarily canids), bears, and flightless birds (e.g. the Emu [Dromaius novaehollandiae]; Spennemann 2018).

Interactions with Other Organisms. Rhynchophorus ferrugineus or the red palm weevil was first identified as harmful to the Indian coconut palm in 1906 (Lefroy 1906), subsequently also being implicated in date-palm damage in 1917 (Brand 1917). Following its discovery in the Gulf Region in the mid-1980s, the weevil spread rapidly to several date-producing countries via infested planting material, primarily transported for ornamental gardening (Faleiro et al. 2012). Now reported across Asia, Africa, Europe, and the Americas, the red palm weevil has thus become a worldwide phenomenon (Giblin-Davis et al. 2013). In recent years, R. ferrugineus has been responsible for wreaking the most insect devastation on palm plantations across the globe (Bertone, Michalak, & Roda 2010). The recommended method for dealing with this is integrative, combining strict quarantine measures, insect traps, careful pesticide treatment, additional natural enemies (biological control), etc. (Al-Dosary et al. 2016).

Morphological Characteristics

Trunk. The date palm trunk is called a stem or stipe. Shaped as a column, it exhibits no side branching. The girth of the trunk not increasing once the canopy of fronds has fully developed, it creates no growth rings. Either single stemmed or forming a clump with several stems from a single root system, it can reach 20 meters in height (Zaid & de Wet 2002).

Leaves. Date palm leaves are between three and six meters long, remaining functional for ca. 3–7 years. Their wide base narrows towards the top, both sides bearing between 10 and 60 spines. Unlike other fruit trees, the P. dactylifera does not shed its old leaves nor do they drop on their own, they are removed only under cultivation. An adult date palm has approximately 100–125 green leaves with an annual formation of 10–26 new leaves. Under good cultural conditions, one leaf can support 1‒1.5kg of dates (Zaid & de Wet 2002).

Flowers. A dioecious species, the date palm produces both male and female flowers in clusters on separate palms. In the early stages of growth, the inflorescence or flower cluster is enclosed in a hard covering known as a spathe. This protects the delicate flowers both mechanically and from harsh environmental conditions (Zaid & de Wet 2002). When the flowers have matured, the spatha splits open, exposing the inflorescence to pollination. The female inflorescence carries ca. 8,000‒10,000 tiny creamy-colored flowers, the male inflorescence an even higher number (Chandler 1958, 205–28; Zaid & de Wet 2002).

Male inflorescence of Phoenix dactylifera. Image was taken from www.flora.org.il. Credit: Dr. Ori Fragman-Sapir.

Fruit. The oblong-shaped fruit—known as a drupe—consists of an external shell, a fleshy part, and a single hardened seed (Zaid & de Wet, 2002).

Seeds. Seeds weigh between under 0.5 g–4g, vary in length between 12 and 36mm, and are between six and thirteen millimeters in breadth, being oblong in shape (Zaid & de Wet, 2002).

Roots. As a monocotyledon, the date palm has no tap root (a substantial root growing vertically downward). Its root system is thus formed by thin, branching roots that grow in clusters from the base of the stem. Its roots can thus extend as far as 25m from the palm and deeper than six meters (Munier 1973). This gives the tree access to ground water, allowing it to endure drought conditions for relatively long periods (Zaid & de Wet 2002).

Distribution and Habitat

Current distribution map of Phoenix dactylifera. Taken from www.gbif.org. In this map each point represents the number of species occurrence records. Darker colored points indicate more occurrences.

Grown in the arid regions of the Arabian Peninsula, North Africa, and the Middle East (Chao & Krueger 2007), the date palm is a very ancient fruit crop. It has been domesticated for several millennia in its centers of origin, diversity and domestication in the Middle East and North Africa, thence spreading to other sandy, hot and (semi-)arid regions and oases that possess sufficient moisture in the form of groundwater or irrigation. Requiring large volumes of water for growth and fruit production, it tolerates saline conditions but is not truly adapted to extreme saline habitats (Krueger 2021).

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Abu-Zahra, T. R. and M. A. Shatnawi. 2019. “New Pollination Technique in Date Palm (Phoenix dactylifera L.) Cv. ‘Barhee’ and ‘Medjol’ under Jordan Valley Conditions.” American-Eurasian Journal of Agricultural & Environmental Sciences 19: 37–42.

Al-Dosary, N. M. M., S. AlDobai and J. R. Faleiro. 2016. “Review on the Management of Red Palm Weevil Rhynchophorus ferrugineus Olivier in Date Palm Phoenix dactylifera L.” Emirates Journal of Food and Agriculture 28: 34–44.

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Giblin-Davis, R. M., J. R. Faleiro, J. A. Jacas, J. E. Peña and P. S. P. V. Vidyasagar. 2013. “Biology and Management of the Red Palm Weevil, Rhynchophorus Ferrugineus.” Pages 1‒34 in Potential Invasive Pests of Agricultural Crop Species, ed. J. E. Peña. Wallingford: CABI.

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