ETHNOBOTANY : CATEGORIES

Human food/ diet

Food is not only necessary for phsical survival but also vital in constructing cultures. The realization of the interaction between plants and people as a part of a long term cultural construction can be very important for archaeologists (Gosden1999:1). Anthropologists began to study about food particularly after mid1960s, following the works of Lévi-Strauss (English translations e.g.1970), and tried to understand food as a cultural system. They recognized the taste is culturally shaped and socially controlled, and treated as analogoues to language (Caplan 1997). Historical changes and political economy also taken into account in later studies, but the significance of food remained untouched.

Food to share, picture taken by F.Ertug in Aksaray.

These studies also indicated that potentially edible items ignored in many cultures. While food remains has long been studied by archaeologists, there is now a growing awareness of the value of studying the social context of food (Gosden 1999; Hastorf 1991; Palmer and van der Veen 2002; van der Veen 2003). Archaeobotanists have traditionally focused on the reconstruction of agricultural practices and the production of food, relying mostly on the habitat and physical properties of plants (Palmer and van der Veen 2002: 195). Some ethnographical and anthropological observations covers areas that interest archaeobotanists, and ethnographical analogies have been used both by archaeologists and archaeobotanists, but usually they do not include necessary details related to plants (such as no identifications of edible wild/weed plants) and their socio-economic meanings.

Since our divergence from apes, humans have been hunter gatherers for 350.000 generations, and mostly agriculturalists for some 600 generations (Pretty 2007:5). Pretty accepts the dates of 7 million years before present (BP) for human divergence from apes, 12.000 BP for the start of agriculture and 20 years for the average generation length. This fact indicates that peoples in every part of the world discovered a wide range of edible plants, dependent on them for such a long time, and this way of subsistence, namely gathering was successful way for many cultures. Indeed biologically all animal kingdom, including humans, were dependent on plants, but people were not only eat them to fill their stomach, and fulfill their basic needs, but they selected, dried, cooked, fermented, stored, seeded, tolerated, burnt or replaced some plants, thus changed their environment, created cultural traditions around the plants and animals that they were in relation. In some early literature on the origins of agriculture the mode of hunting-gathering were treated as a backward, and particularly unproductive, parasitic way of life, and phrases such as ‘the emergence of agriculture’ was quite common (Binford 2002: 198). This view of ‘progress’, evolution to some inevitable end point challenged with many ethnographic and ethnoarchaeological work (Harris and Hillman 1989; Lee 1965; Turner 2005).

Plants for food, including cereals, pulses, vegetables, spices and fruit are the largest group within the cultivars. Ethnobotanical studies indicate that the number of domestic plants cultivated by the contemporary farmers is astonishingly limited. In any area, domesticates hardly exceeds 70, including not only food, but also fuel, fodder, fiber, building, dye and medicinal cultivars (Ertug 2000a). Even today many people enlarge, diversify, add taste, color and nutrition into their diets by wild plants, e.g. greens, mushrooms and fruits. In rural areas the gathering of wild greens, mushrooms, herbs and fruits are very important part of the diet both today as well as in the past (e.g. Ertug 2000a; Mears and Hillman 2008; Pieroni 1999; Price and Ogle 2008).

Cereals

The cereals are plants in the grass family, the Poaceae (previously named as Graminae), whose members produce edible and nutritious seeds, the grains (McGee 2004: 453). As they produce most durable and concentrated foods they become our main staples, particularly for bread and beer and they have a special role in our diet and cousine. But only recently, toward the end of 20th century, we came to realize that seeds offer us more than just starch and protein, hundred and thousands of chemicals are concentrated in the outer protective and active layers of the seed, which we clean off to produce refined grains (McGee 2004:455).

  • It is often assumed that wild grasses were as important for hunter gatherers as domesticated cereals were for early farmers, but archaeobotanical and ethnographical evidence instead suggests that hunter-gatherers took an opportunistic approach to the resources available and their subsistence strategies were not necessarily centred on grasses and ‘wild cereals’ (Savard et al 2006). However, cereals became one of the major staple throughout the world as they can be stored for long periods and provides basic starch and proteins.
  • Of the approximately 10.000 species of grass, perhaps 50 are cultivated and only 12 are qualified as major crops (Evers and Nesbitt 2006). Major cereals for human diet which now cultivated internationally are limited to a few species, such as wheat (Triticum spp.), rice (Oryza spp.) and corn (Zea spp.). Oats (Avena spp.), rye (Secale spp.) and particularly barley (Hordeum spp.) which was once considered as human food, now has a quite limited role in the human diet, basically cultivated for fodder.
  • Various other cultivars also play minor roles in limited areas such as sorghum (Sorghum spp.), amaranth, millet (Pennisetum spp.) and buckwheat. For example some 50 species of grasses are extensively harvested in the Americas yet only six have been domesticated (Wickens 2001: 171). Particularly three species, maize, rice and wheat, accounted for %85 of the world's cereals in 2001 (Evers and Nesbitt 2006).
  • Hard wheat and bread wheat have different ecological requirements. Durum wheats are well adapted to the Mediterranean-type climate with mild, rainy winters and warm, dry summers. Aestivum wheats, on the other hand, are more adapted to extreme continental conditions and to sub-humid temperate climates (Zohary and Hopf 2004).
  • The rice (genus Oryza) contains ca. 20 species distributed through the tropical and subtropical regions of both hemispheres, growing in humid forests and open swamps (Wickens 2001: 159).
  • While the farmers of the Europe and Western Asia were providing their bread preferably out of wheat, farmers of southern and eastern Asia use rice as their main staples, and the farmers of Americas depend on corn (or maize) as their main crop. Maize is not only valuable source of starch but also has a higher oil content than most other cereals, and also extensively grown as fodder crop (Wickens 2001: 162-3). Indeed the grains and stems of all cereals and grasses are important as fodder, and most of the cereal crops has many other uses.
  • Almost all cereals needs several stages of after-harvest process, such as separating them from the stems and drying, then further processes of cracking, grinding/milling and baking. In the case of rice, the grain is usually eaten boiled or cooked as pilav after hulling the grain, but can also be grind to flour for rice bread or beer, known as sake. We will explore some of these processing techniques briefly in the next chapter: Clues to archaeobotanists. In this chapter we will cover though shortly various kind of main end-products we produced from grains:
  • Flour of wheat, barley, rye as well as corn and rice can be used within many different products, while the bread probably the most important of all. It can also transferred to and eaten as porridges, soups, cakes, pies, pasta, and other food stuffs. Ground products such as flour are rarely detected in archaeological records, however various indirect and some direct evidences available.
  • Bread, is a very important staple throughout the world, and has so many different varieties, names according to the cereal it has been made, the way it has been processed, fermented or leavened, the way it has baked, shaped; and has a symbolic value. While we do have some direct early information from other parts of the world, ancient bread remains is still uncommon, often difficult to recognise and little studied (see Samuel 2004 for an overview and further references). While charred as well as desiccated remains (majority of remains from ancient Egypt) of ancient breads were found and studied, waterlogging does not allow processed cereal foods like bread to survive (Samuel 2004). We do not know how and when the bread became main staple in various societies, but we know for example about 200 bread varieties listed in the cuneiform tablets of Mesopotamia, early 2nd millennium BC (Bottéro 2004: 22). These breads differ according to the flour type, the kneading, the additives, the flavors, the cooking methods as well as the presentations.
  • Consumption of bread in which the grain has been hand ground and, therefore, not always completely refined, has been shown to affect the dentition severely (Molleson 1994). These dental records and indirect evidences such as ovens, tandurs and shaping pots of bread, as well as the starch residue analysis may provide further direct evidences related to the prehistoric bread. Further, we can find perfect wooden models of bakery-brewery shops from 12th dynasty tomb in Thebes, Egypt (Curtis 2001:Pl.7). They provide us actual images of women grinding grain on a raised quern and they prepare different shaped loaves of bread, which actual bread remains also found in tombs.
  • Ethnographic analogies not only provides the various techniques to handle the grains, ways of processes and end-products, they also provide clues about the cultural settings, meanings of bread and other grain based products. For example wheat bread is a higher-ranked food than barley bread in the Near East for many centuries. Bread was and still meant ‘the food’ throughout the Near East (Ertug-Yaras 1997; Palmer 2002). The bread occupies the primary place above all foods in many cultures, and it is the essential part of all meals, and snacks. In Anatolia, a piece of bread is never thrown away, except given to animals; when it is seen on the ground, it has picked up and put on a higher place, such as a top of a wall, because it is sacred, 'sent or given by the God'. Wheat and bread has symbolic values, that appears at every stage of ceremonies throughout the life. In weddings the wheat thrown over the head of the bride as a symbol of fertility, when the first teeths of a baby is seen, the family boils some wheat and invite the relatives and neighbors. After the death, a meal is given, called ‘ölü Ekmegi’ (deads bread). Several types of wheat bread, leavened or non-leavened, some with additions of barley flour or rye has produced for different occasions (Ertug-Yaras 1997).
  • Another basic staple made with wheat is called bulgur in Anatolia and the Near East and in Tunisia, but not in Iran, nor in Egypt (Sigault 1988:5). It is further named according to different particle size, which used in different recepies. In general they produced by parboiling the wheat and after dried and dehusked in mortars or mills, it has cracked/ground in hand-mills. Bulgur is used as rice and cooked as pilav, added to soups, used in stuffed vegetables, and added to almost all vegetable meals. Archaeological recognition of cracked wheat (bulgur) is a recent issue among archaeobotanists (Sarpaki 2001; Valamoti 2007). Due to the excellent preservation in the Late Bronze Age site in Akrotiri (Thera, Greece), flour, bulgur and some processed legumes have been detected, further the awn fragments retained in the flour indicated the barley flour were much more common than the wheat flour, fourty-five samples of barley and only three of wheat (Sarpaki 2001:34).
  • Firik or frika is roasted wheat, harvested when not fully ripen, is also highly valued in some areas of the Near East (Hillman 1985, Palmer 2002). It is eaten as a snack or can be cooked as rice, 'pilav'. In Anatolia kavut or kavurga is also valued form of wheat, washed, roasted then coarsely grinded, and eaten as snack or cooked with milk. These roasted forms are also good for long term storage.
  • Beer making was another important use for cereals, usually made with barley. When the grain soaked in water, grain itself supplied the enzyme to ferment (McGee 2004: 740). There are clear evidence that wheat and barley beers brewed in Egypt, Babylon, and Sumeria by the third millenium BC. Not only vats and related pottery, but stels, reliefs of brewing and drinking beer provide clear images from Egypt (Curtis 2001: Pl. 11, 12). But using of hops (Humulus lupulus) to add taste to beer, start around 900 AD in Bavaria (McGee 2004: 741).
Wheat field, Kastamonu 2008, photo taken by F. Ertug.
Baking bread in oven, Datca, Mugla 2007, photo taken by F. Ertug.

Legumes/ pulses

Legumes are second only to the cereals in importance for food, but some substances in many edible legumes limits their overall reputation, and in some areas they are regarded as non-prestigious foods, such as in both the New World and Africa south of the Sahara (Wickens 2001:180-81). In the Near East and throughout the Mediterranean basin they are among the earliest plants contributed to human diet in their wild form, and they are among the early domesticates. Pea (Pisum sativum), lentil (Lens culinaris), chickpea (Cicer arietinum), chickling vetch (Lathyrus sativus), flat-podded vetchling (Lathyrus cicera), horsebean (Vicia faba) were among the earliest cultivars in the Near East, Anatolia and the Levant. Pulses, whether wild or domesticated generally collected easily, does not need any tool, and ripen earlier than cereals, and most of them can be eaten before ripened, when they are in green. Some immature fruits may contain lower protein but are relatively richer in vitamins and soluble carbohydrates, so many pea and bean varieties can be used as fresh vegetables (Wickens 2001:180). In their half- mature stage, pulses, especially chickpea, garden-pea and horse bean may be roasted and eaten, while dried pulses need more preparation, such as soaking (Kislev and Bar-Yosef 1988: 176; ). Some toxic legumes, such as horsebean can not be eaten by individuals with hereditary glucose-6 phosphate dehydrogenase deficiency, known as Favizm (ibid:176). Another legume, some species of Lathyrus produce edible seeds in very poor soils, but when consumed in high quantities it can create paralysis in legs, which is known as Lathyrizm. The soaking and boiling of seeds of these varieties as well as Lupin is a well known detoxification method.

Green beans in market, Kastamonu, Turkey, 2008, photo taken by F.Ertug.
Woman selling fruits in Kastamonu market-Turkey, 2008, photo taken by F.Ertug.

Fruits / nuts

Botanically a fruit may be defined as the structure that develops from the ovary wall (pericarp) as the enclosed seed or seeds mature, and it can be succulent (e.g. berries) or dry (e.g.nut), simple or compound, true or false (e.g. the apple-the swallow receptacle is eaten) (Wickens 2001:175-6). Some botanical fruits can be considered as vegetables (e.g. aubergines, cucumbers, gourds, tomatoes) and some others like beans considered as legumes. Here we will use these daily accepted terminology of diet, not the botanical meaning. Another description of the fruits is 'they are parts that the plant creats in order to attract animals to eat them and disperse the seeds within them' (McGee 2004:350). So they are usually contains sugars and acids, has pleasing aromas, and eye-catching colors.

  • Common fruits of temperate climates are apples, pears and quinces (all belongs to Rosaceae family) and they usually keep well when stored. Stone fruits belongs to genus Prunus in the same rose family, and include apricot, cherry, peach and plums, and they can be dried or stored in the forms of jam, jelly, etc. Berries including grapes, are usually small fruits borne on bushes and low plants, not trees (McGee 2004:360), except of grapes most are not cultivated, but widely collected. Warm climate fruits includes melon and citrus plants as well as date, fig, and cactus pear (Opuntia ficus-indica). Tropical fruits like banana, pineapple and mango were limited to specific areas until a century ago and they were luxuries (McGee 2004:378).
  • Some of these fruits and nuts can be considered staple agricultural products particularly in the Mediterranean basin, and the first fruit trees seem to have been brought into cultivation in the Near East, yet relatively later than the cereal crops, c. 4th millenium BC (Zohary and Hopf 2000:142). Olive, grape vine, sycamore fig, date palm, pomegranate and the fig were the first fruit trees cultivated in the Old World.
  • As most fruits contains alcohol, many fruits can be brewed. Various sprits can be produced from figs, pears, dates, berries. The wine from grapes probably among the earliest drinks, and the most popular one.
  • Olives are important crop trees of all Mediterranean, and both its fruit and oil are valued. Usually olive trees easier to cultivate than cereals, and the farmers favor of olive cultivation as it brings more cash. The busiest time is during harvest in October-January, when whole families go into the fields to help collecting (Palmer 1999). Olive trees require some tending -weeds have to be removed by ploughing and the trees have to be pruned, but they are considered a long-term investment.
  • Acorns of all oaks are potencial edibles if they processed properly. They can be gathered like all other nuts from the ground in the fall, by women and children. They require less process if they are sweet, can be aten like sweet chestnuts, by roasting or by boiling. If there is a need to produce flour, they can be grinded and mixed with cereals to make bread or mash and soup.
  • Nuts include the true fruits such as hazelnuts (Corylus), beechnuts (Fagus) and acorns (Quercus), as well as drupes such as walnut (Juglans), almond (Prunus dulcis or Amygdalus communis), and loosely used as any seed or fruit consisting of an edible kernel, surrounded by a hard shell (Wickens 2001: 177-78). They provide valuable proteins, oils, mineral and vitamins. They are quite often found in large quantities in all archaeological contexts due to their shells' higher chance of charring. Not only the shells of nuts, such as almond is frequently find within archaeological contexts, but also acorns are quite commonly found in high quantities from earliest settlements on (Zohary and Hopf 2004; Savard et al 2006).
Acorns, F. Ertug.
Almonds ('payam/ badem'), Datca, Mugla-Turkey, 2008, photo taken by F.Ertug.

Vegetables / greens/ tubers

The vegetable is defined here as the edible part of a wild or cultivated plant which is traditionally not classified as a grain, fruit or nut and is eaten either cooked or raw (Wickens 2001: 179). They can be bulbs such as onion (Allium cepa), corms such as taro (Colocasia esculenta), root tubers such as sweet potato (Ipomea batatas), stem tubers such as potato (Solanum tuberosum), swollen taproot such as carrot (Daucus carota), inflorescence such as cauliflower (Brassica oleracea), and leaves such as spinach (Spinacea oleracea). Edible algea and fungi are also treated as vegetables in our diet.

  • Vegetables that we cultivate today, although seems numerous compare to other domesticates, are limited to 20-30 (Ertug 2000a). Contrary, the wild “plant-kit” in every area is much higher. When we check the numbers of wild edibles collected in one area it changes from a few to hundreds, according to the peoples’ knowledge rather than the environmental restrictions (see also gathering from wild in next section: Clues to Archaeologists).
  • Basic garden vegetables like garlic, onion, leek, cress, mint, lettuce, turnip, rocket, fennel, dill, are not usually found in archaeological records, they are highly perishable. However, the tablet archives from Babylonia provides these and others plant names of royal gardens of the King Marduk, who reigned at Bablylon around 700 BC (Finkel and Seymour 2008: Fig87, p. 110). Some earlier cuneiform tablets from around 1600 BC of Babylonian collection even provides receipts containing onions, leeks, and garlic (Bottéro 2004). In addition to written and visual sources, better preservation conditions of dry climates, e.g. Egypt, provides numerous non-carbonized remains of vegetables and tubers (Zohary and Hopf 2004: 192), as well as waterlogged sites.
  • People gathered various tuberous parts, roots and rhizoms from wild for their starch and taste. Tubers of five species and roots of two plants have been recorded as edible in Central Anatolia (Ertug-Yaras 1997), and they are all eaten raw, and except the Crocus, they are not consumed in large quantities. Turner (2005; 2006) explores the gathering and cooking of traditional root vegetables of NW North America, and provide details of gathering, processing and the social aspects.
A group of woman collecting wild plants in Central Anatolia. F.Ertug.
Growing your own leafy greens, Aksaray. F.Ertug.

Oil plants

Oils and vegetable fats are usually produced from the seeds of various plants, while the oils are liquid at 20 C, fats such as cocoa butter which produced from the beans of cacao tree are solid (Wickens 2001:184). Sesame, sunflower, maize, soybean, olive, mustard, popy, and cotton oils as well as palm oils are considered main sources of vegetable oils, and used mainly in cooking and salad oils. They can be used as substitute to animal based fat. Different oils were used in cooking in different parts of the world according to the growing conditions and peoples choices. Olive trees (Olea europaea) are the native of the Mediterranean basin, and the oil produced from fruits are traditionally used in cooking, in soap producing, as lamp oil, and in so many medicinal treatments. Usually the ripened olives are ground into paste using large millstones, then pressed into sacks or baskets, which are stacked on top of each other in a column, then placed into the press. Pressure is then applied onto the column to separate the oil from the paste.

  • Flax is the earliest oil and fibre plant of the Near East (Zohary and Hopf 2004). The linseed oil produced from the flax (Linum usitatissimum) and Eruca sativa were widely used in Central Anatolia as a cooking oil; while olive, sesame, cotton, popy, sunflower, hazel, Cephalaria, safflower, and hackberry were the main oils in other parts of Anatolia (Ertug 2000b). Most of these vegetable oils were not useful only in the cusine, but their residues were used as fodder, especially for draft animals such as oxen and buffalo.
  • Almost all vegetable oils but particularly olive, sesame and linseed oil were important in medical treatments.
  • The seeds of Lallemantia (Lamiaceae) found at Bronze Age sites in northern Greece. At several of these sites, the seeds were found in significant concentrations in storage contexts, suggesting that they were deliberately stored for use by the inhabitants. Oil from the seeds of Lallemantia can be used for a variety of purposes, including food, lighting and medicine. This genus is not native to Greece, the nearest modern occurrences of Lallemantia species being in Anatolia fromwhere they extend further east as far as Iran, or beyond (Jones and Valamoti 2006).
  • In Morocco, Argan oil is extracted from kernels of the fruit of an endemic evergreen tree, Argania spinosa (Wickens 2001:184). The fruits are broken and their kernel are grind by the Barber women on small hand mills to produce a heavy oil. In the past, people collect undigested argan pits from the waste of goats which climb the trees to eat their fruit (http://en.wikipedia.org/wiki/Argan_oil#Extraction_of_the_argan_oil). The oil is used both as cooking oil and in medicine and cosmetics; in addition to the trees other uses such as forage, timber and fuel.
A linseed oil mill, Aksaray-Turkey, 1995, photo taken by F.Ertug.
A traditional olive oil millstone and baskets, Morocco, 2006, photo taken by F.Ertug.
Argan trees with goats, Morocco, 2006 Photo taken by F.Ertug.
Fruits of argan tree, Morocco, Photo taken by F.Ertug.
Processing argan oil by hand, Morocco, Photo taken by F.Ertug.
Processing argan oil by hand using a hand-mill, Morocco, Photo taken by F.Ertug.

Additives/ herbs/spices

Herbs and spices seems of a minimal interest within the subsistence of humans, however it covers the demand of humans for diversity, for a healthier living, and needs of exploration. For example the desire for spices in Europe during the Middle Ages, from A.D.1000 until 1500s, was considered as the main force for the exploration of trade routes to the Far East and the America and to the later developments of colonisation (Freedman 2008; Dalby 2002). Spices played a very important role not only in culinary and as drugs, but had a significant social roles, such as indicators of material comfort and social prominence. Symbolic links of fragrance to health, sexual powers and sanctity (as anointment oils and incence) was also important. Spices like black pepper, cinnamon, ginger, nutmegs, cloves and saffron were the most common additives to food in medieval Europe, inspite of their expense and hardship to find, and they are still in use by milions of people to add taste into their food and beverages.

Tea plantation in Rize, Turkey, photo taken by F. Ertug.
  • The cinnamon (Cinnamonum zeylanicum and other species; Lauraceae), whose bark is harvested in sheets or quills from the trunks and branches, is one of the ancient tastes, and still highly valued in many cuisines worldwide. It is also known with its medicinal properties.
  • The most important new spice, unknown to the ancient world was sugar, which was imported from the East, considered as an exotic, sold in small quantities, and credited with marvelous properties (Freedman 2008:12). Until the cultivation of sugarcane in Spain, Sicily and eastern Mediterranean by the fifteenth century, honey and dried fruits were available as sweetener. In addition to those, edible inner bark of many tree species has been considered as a famine or emergency food, a staple food, a medicinal or health food, and a rare delicacy among different cultures (Turner et al in press). Inner bark of many species, at the right stage and weather conditions, is sweet and good-tasting, and contains high concentrations of sugars and vitamin C (Swetnam 1984).
  • In North America, for thousands of years people have been capturing the sweet liquid sap of trees like maple (Acer spp.), birch (Betula spp.), and larch (Larix spp.). Indigenous peoples have learned how to harvest maple sap by tapping into the trunk in the springtime, then concentrating it into a syrup (Munson 1989).
  • Another very ancient sweet taste from trees of the Mediterranean and the Near East is manna, which mentioned in the Bible as well as in the Qur’an, as a mysterious food miraculously appearing in the desert to feed the starving Israelites on their way to Canaan. Today, the Bedouins eat a food called ‘Sinai manna’, which is probably a lichen carried on the wind, or possibly resinous sections of vegetables after insect attacks (see Turner etal in press; Baytop 1999 for discussions of manna and its identities). Another kind of food that is called manna, however, is a sweet resin from ash trees (Fraxinus oxycarpa and F. ornus), which was harvested as early as the 16th century in Calabria, Italy, then later, in Sicily, as a sweetener and natural laxative (Turner etal in press).
  • Among the beverages, tea and coffee holds a very important place in the last few centuries throughout the world. Tea is produced from the tip leaves and buds of an evergreen tree (Camellia sinensis), which grows mainly in tropical and sub-tropical climates. It is a well known beverage in China for thousands of years, and used as medicine and freshener throughout the SE Asia, then both its use and later its cultivation spread to the world (http://en.wikipedia.org/wiki/Tea and see http://www.fda.gov/FDAC/features/296_tea.html). Another important beverage, produced from the coffee berries, which contain the coffee bean, are produced by several species of small evergreen bush of the genus Coffea (http://en.wikipedia.org/wiki/Coffee). It is probably originated from Ethiopia in Africa, known as early as 9th century, and spread much later than tea. It was in Arabia that coffee beans were first roasted and brewed, similar to how it is done today. By the 15th century, it had reached the rest of the Middle East, Persia, Turkey, and northern Africa, then introduced to Western world. Both of these plants have a very important role not only in the world trade but also how they have adopted, and how they percieved by different cultures of the world.

Medicinal plants

Medicinal plants are those used for human and veterinary treatments in traditional applications, and today over 125 pharmaceutical products in current use in the West are plant derived, of which ca. 75% were discovered by investigating traditional medicines (Wickens 2001:318; Mabey 1988). According to some sources roughly 50,000 species of higher plants have been used medicinally (http://www.plantlife.org.uk/international/plantlife-med-plants-what-are-med-plants.htm). Drugs can be provided from the leaves, seeds/fruits/cones, roots or barks of plants, and can be prepared in many different ways. They can be internally used, in a form of tea, can be made into tablet by mixing with flour, or the herb grinded to swallow or drink; fresh, boiled or heated leaves can be applied externally, a poultice can be prepared, a tar can be applied, etc. In some cases a few ingredients need to be mixed to have a more potent result.

Opium poppy, photo taken by G.Hillman.
  • In some caves related to Late Pleistocene and Early Holosene at northwestern Thailand, dated between 11.000 to 2500 BP, about 28 food and/or medicinal plant remains found either charred or calsified condition. Archaeologists realized that some identified taxa, such as Licuala spinosa fruits are utilized today for medicinal purposes by Thai village doctors (Pyramarn 1989:285).
  • The evidences of successful signs of healing after trepanation of the skulls has been found from the Neolithic on, ca. 9000 BP (e.g. at Asikli in Anatolia), suggests an early knowledge of anaesthetics and possible antibiotics (for historical information see: Duin and Sutcliffe 1992; http://www.asiklihoyuk.org/AHeng.html). Similar applications are recorded in various parts of the world from the Europe to Meso- America.
  • One of the earliest analhesic for example can be opium popy (Papaver somniferum), which was one of the earliest cultivars, together with cannabis (Cannabis sativa) for the Old World. Both plants had a long history of medicinal use to relieve pain, in addition to many other uses in various treatments. The earliest yet known opium popy seeds found in a waterlogged site of La Marmotta in Italy, dated ca. 7700 BP in an early Neolithic settlement (Merlin 2003:302; Kunzig 2002).
  • In a recent review of archaeobotanical records indicating that species such as Ephedra, Peganum harmala, Papaver somniferum, Cannabis, Nymphaea nouchali and Mandragora officinarum have probably been used for mind-altering purposes in the Old World, but they have also been employed for a variety of other reasons (Merlin 2003:300).
  • Quinine, from the bark of Cinchona officinalis was a popular medicine of South American local populations against fever and malaria, and it became very valuable to Europeans in expanding their access to and exploitation of resources in far off colonies.

Human therapy & Food-medicinals

Hundreds and thousands of plants considered as medicinal by peoples and about one third of them is directly consumed, eaten or drinken, so these can be called food-medicines. Others can be poisonous, toxic plants, but when the amount (dose) is taken by control those can treat, cure human sicknesses. It is usually very difficult to make a distinction between a food plant and a medicine in an archaeological record. Pharmacologists all over the world keep researching, testing, screening the plants to find new compounds to cure various diseases or just to prevent sickness. However, ethnobotanists or medical ethnobiologists' focus is not only the plants to heal people but holistically on the medical belief system as an integrated system, not as a series of isolated, unrelated beliefs about illnesses and their treatments (Berlin and Berlin 2005: 236).

  • Ethnobotanical studies indicate that medicinal plants constitute the second place in importance after edibles (Ertug 2003b; Pieroni et al 2002).
  • The doses and the frequency of application is also very important aspect of the folk medicine, and usually associated with prayers, and rituals. Some of the applications are so interwiened with rituals that it is hard to tell if the application can be considered as herbal or not.
  • In any society, medicinal knowledge can be in domain of a person (healer, shaman, sheih), a family, and/or a small group, such as priests within a temple. There are always suppliers of herbs and herbal shops (aktar/ attar in Turkish and Arabic) in many parts of the world, where people can find not only the herbs that grow around them, but the ones traded, imported from other areas. Either healers houses, clinics or herbal shops, these places might differed in context from other spaces of the same settlement, could have stored a large variety, larger amount or more distant, even exotic plants. Although this can also indicate a social difference, status and/or job (like a merchant's house or a collectors'), it may also indicate a healer's house especially if some of the plants have known medicinal uses.
  • The women’s medicinal plant knowledge usually differs from the men's, and they inherit the knowledge and remedies related to reproduction, and particular topics such as conception, pregnancy, birth, contraception, menstruation, post-partum (Smith-Oka 2008). Their experience is usually not only limited with healing women, and many women healers treat both sexes.
  • Many plants, and the different parts of the same plant might have multiple uses. For example, tree pitch, especially from coniferous trees, is used in multiple ways, including as chewing gum and for medicine (Ertug 2004; Kuhnlein and Turner 1991). Indigenous peoples of western North America chew spruce (Picea spp.), hemlock (Tsuga heterophylla), and other types of hardened pitch, and many consider tree pitch to be one of the best all-round medicines for treating a host of ailments from wounds and skin infections, to tuberculosis and cancer. In Anatolia, medicinal resins and gums are obtained from pistachio (Pistacia lentiscus), fir (Abies nordmaniana), and pines (Pinus brutia and other pine species) (Baytop 1999; Ertug et al. 2004).
  • Some plants such as Arum species (Araceae) have some poisonous properties, yet, both their tubers and the leaves can be eaten after drying and/or boiling (Grieve 1996:236; Baytop 1994: 287; Balos and Akan 2007). Medicinal properties of Arum dioscoridis is also recorded, such as its fruits is used against scorpion bites, its roots is dried and eaten in small amounts against haemorrhoids (Ertug 2004).
  • Herbal teas, usually prepared either by boiling or infusion of aromatic species belongs to Lamiaceae family, such as sage (Salvia spp.), thyms (Thymus spp, Origanum spp.) considered not only as a good hot drink, but used as preventive or for treatment of colds, coughs, simple ackes. While in the coastal areas of Anatolia and in general around the Mediterranean (see also Hanlidou et al 2004), the frequent use of members of the Lamiaceae in therapy is characteristic, while the frequent utilization of coniferous plants seems to be the characteristic of the inner regions (Yesilada et al. 1995).

Animal treatments/ Ethnoveterinary

Veterinary practices are as important as human's health particularly for the peoples who based their living on pastoralism and/or animal husbandry. Although there are always some specialist healers in traditional societies, many shepherd or animal owners has a knowledge of plants who treat animals. Some cultivars are used by many, such as barley flour, olive or linseed oil and garlic to treat sheep and goats, but usually herbs from the nature used. In Anatolia some plants are used both to treat humans and animals such as Origanum, Dracunculus vulgaris and Vitex; some others solely used for animals, such as Daphne gnidioides (Ertug 2004). Ethnoveterinary medicine is a poorly developed research field with much potential. There are some early works where we have information on animal treatment as a part of local plant use. For example among Hausa of Nigeria, the rhizome of ginger (Zingiber officinale), which was once used in Western medical practice as a stimulant and carminative in cases of dyspepsia, diarrhea and colic; its essential oil is still applied therapeutically in veterinary practice (Etkin and Ross 1982: 1568). In a much recent study Gradé (2008) investigated not only the ethnoveterinary practices of pastoral peoples of Karamoja- Northern Uganda, but the self-medication of the livestock. This aspect was not well investigated before except a few studies, while ethnoveterinary knowledge has probably originated from careful animal observation. In this environmentally harsh area of Uganda, over 200 plant species' use in ethnoveterinary medicine has recorded, which very few has been recorded for animals before (Gradé 2008).

Arum species are used as food and medicinal, despite their toxic nature, Turkey, F.Ertug.
Cistus species leaves heated and externally used against rheumatism and other pains. Turkey, F.Ertug.
Coridothymus capitatus oil is distilled and used against stomach acke, Turkey, F.Ertug.
Hypericum perforatum is used either as tea against headackes or its oil applied on wounds, Turkey, F.Ertug.

Fuel/ Fodder/ Forage

Fuel and fodder combined under the same title although their uses are distinct, most of the plants can be used for both purposes. Almost all trees and shrubs can be used as fuel, and their leaves, twigs can be gathered, coppiced or browsed as fodder. It is also noted that once the leafy branches were eaten by the animals, the leftover twigs and branches can be used as fuel (e.g. Halstead and Tierney 1998). Fuelwood can be provided from trees, shrubs, herbs and crop residues, and the amount of energy obtained when burnt will vary according the moisture content and the density of the wood (Wickens 2001:255). Forage refers to all browse (the tender shoots and fruits of shrubs and trees) and herbaceous animal feed (ibid:209). Indeed some of the herbaceous fodder plants can be gathered and used as tinder plants. The straw and garden residues are also important fodder and fuel sources.

Mother and daughter carrying Chondrilla juncea to fed their animals, Nigde-Turkey, F.Ertug.

Craft related plants

While some of the crafts solely based on plants as their main supply, some other crafts can use some plant based material, but their main material can be leather/skin, metal, glass, soil, etc. We will cover briefly the vegetable fibers which mainly used in textile, cordage and basketry, as well as dye plants, gum and glues.

The timber of course a very important material for all building-related crafts, and provides us shelter and many plant based materials, but it will not be examined here among the main uses of plants. The carpentary, carving, wood working, building and furniture making were not presented among these crafts, but certainly most of trees can be used by artisans and/or laymen for the above indicated methods for many porposes, and these crafts can became art forms when made for special purposes and by their specialists

  • Tinder and kindling are also necessary components to fire wood as the dung- cakes. A large number of herbs can be used as fire starters. One source is the resin-rich barks of pines and other species, trimmed off for use as fire starters, and leaving a characteristic scar on the living trees, of which is also called as 'culturally managed trees' (see Turner et al. in press).
  • Pine, juniper and particularly oak species are among the common fuel wood around the Mediterranean, in addition to olive, willow and poplars (Ertug 2000; Ertug et al 2004). Among oaks, evergreen bushes of prickly oak (Quercus coccifera) is particularly well known for its ability of long standing ambers (Ertug et al 2004), and it could be cut fresh for stall-feeding or browsed by sheep and goats (Halstead and Tierney 1998).
  • While oaks are main sources of fuel, not only their leafy branches but also their acorns are collected and fed whole to animals in many parts of the world. In dry areas, they are often the only trees available to provide forage, shade, fuel, or wood for construction; and in the Near East it is the frequent sight of donkeys carrying leafy branches, of stores of fuelwood and forage in villages, on wall tops or in the trees themselves; of the use of branches to provide shade or defence of fields against animals; and by the evidence of management visible on many of the trees themselves (Mason and Nesbitt in press).
  • Fuel choice is distinct in some cases, for example Cistus laurifolius is preferred fuel of cooking in Buldan area of Anatolia, as it is easy to fire and it named as 'gelin gulduren', means make the brides happy; and pruned branches of Vitis vinifera is used to boil the molass from grapes (Ertug et al 2004). In some particular cases, bark can be intentionally selected as fuel, and this can be related a ritual use (Beauclair et al 2009).
  • Human food and livestock feed differs in a way that the former usually processed in a way before the consumption. It is not a necessity for animal fodder, the animals can graze or browse most of the year, in areas with hard winters, long rains (mansoons) or dry seasons stored hay or straw is critical importance, as well as leafy branches. Leaf and twig foddering in most areas of Europe plays such an important role in livestock production that it actually shaped the cultural landscape of the continent and the composition of vegetation cover (Halstead 1998).
  • In many parts of the world the dung of the wild and the domesticated animals is collected from their grazing lands or from the stables and used as fuel (Anderson and Ertug-Yaras 1998; Ertug-Yaras 1997; Kramer 1982:45; Miller 1996; Valamoti and Charles 2005). In some dry- steppe areas the dung use as fuel is considered one of the most important product of animal husbandary. 'Although dung generates lower temperatures than wood, a dungfuelled fire would act like a ‘slow’ oven and could be left burning while other chores were attended to' (Sarpaki and Asouti 2008: 375).
  • Usually barley grain and/or a mixture/maslin of wheat-barley straw given to animals in addition to pulses such as grass pea, common vetch and other vetch types, and these mixtures are changed according to the animal type, their age, the season or if the agricultural product of that year is good or bad. There is also a shifting boundary between the feed and food (Jones and Halstead 1995). If the year is good and enough food available barley can be considered as feed, otherwise some of barley can be mixed with wheat and become bread.
  • All field and garden left overs, stalks of maize, beans, chickpea and lentils can be fed to animals, and stored as stacks outside the barns, bayrs, or in the courtyards. Residues of oil process, such as olive, linseed, popy, sesame can be given to the animals (see oil plants).
  • Charchoal and charred remains covers an important part of archaeolobotanical records, and provides data on firewood and dung use as fuel, as well as fodder use (Miller 1996; Valamoti and Charles 2005). It is possible to make some interpretations related to pollarding of trees for leaf fodder through observations of charchoal and pollen curves (Rasmussen 1990), however the waterlogged evidence can provide further data related to the use of hay-fodder to fed the livestock as well as the seasonality of pollarding (Favre and Jacomet 1998). The data provided in the Swiss lake shore settlements indicates that hazel bushes with catkins were used as an essential protein source in late winter and early spring when stored leaf hay was scarce (ibid 173). Another report related to two waterlogged sites of French Jura shed light on the firewood economy of Neolithic settlements, especially in a domestic context, i.e. firewood used for cooking, heating and lighting (Dufraisse 2006). The data indicates that species abundant in the environment were frequently exploited for several purposes (fuel, timber, etc) whereas rarer species, such as Ulmus, Taxus and Viburnum, were scarcely or never used for firewood (ibid).

Fibre for cordage, textiles and basketry

Cordage is used here as a general term for all ropes, packing cords, string, threads, lines and twines, while the rope generally composed of three or more strands, each consisting of two threads or yarns (Wickens 2001: 270). Some argue that the use of plants for fibre are regarded as second only to food in their usefulness, and there are well over 2000 species with usable fibre (ibid: 263).

  • Fibre for clothing covers a vast diversity, including well-known cultivars such as flax, hemp, cotton, in addition to palm leaves, grasses, and barks of various trees. People developed techniques to obtain and process the fibres, then spin, knit, plait and weave them by simple tools. Various plants are either woven or twisted together into mats, sandals, hats, screens, chair seats, baskets, containers, etc. Very few of these plants has any commercial value, so few, such as willow, cultivated for coppicing.
  • Plants used for mats and baskets are also covering a large range, from the stems of reeds, rushes, grasses, bamboo, rattan, willows to the leaves and roots of many species (Wickens 2001:279). The wood from trees may not immediately seem to be suitable weaving material for basketry, but young, slender branches, as well as thicker stems and wood can split down into flexible strips (Bichard 2008:26). Oak (Quercus spp.), sweet chestnut (Castanea sativa), ash (Fraxinus spp.), hazel (Corylus avellana and other spp.), willow (Salix spp.), and conifers (Pinus, Picea and Juniperus spp.) were popular trees for the basketweawers of the Europe and the Mediterranean basin. While the barks and roots of birch (Betula spp.) was so important in northern latitudes, branches of other shrubs or trees like myrtle (Myrtus communis), chaste tree (Vitex agnus-castus), olive (Olea europea) were used commonly in southern latitudes.
  • Leaves and stem fibers of palm trees and various grasses, and cereal straw, particularly the straw of four commonly cultivated cereals: rye (Secale), wheat (Triticum), oats (Avena) and barley (Hordeum) has been utilized in many places (Bichard 2008: 35). One of their main use was closely related with agriculture, in collecting grains, straw, fruit and nuts as well as dung, carrying and storing them and in processing oils, wine and many other foodstuff baskets has critical importance.
Vitex agnus-castus is one of the most versatile plants, while the leaves and seeds are medicinal, branches used in basketry, F.Ertug.
Mat plaiting with Typha laxmannii, Aksaray-Turkey 1995, photo taken by F.Ertug.
An elderly woman and the mat she has woven with Cyperus longus, Bodrum- Mugla-Turkey 2001, photo taken by F.Ertug.

Gums and Resins

The gums usually provide from the barks or root of some plants, when the bark is cut or injured a sap exudates.

  • The gum from Acacia senegal or its related species, known as ‘gum arabic’ is probably among the most ancient traded goods, for its medicinal property as laxative, food additive and glue uses (Wickens 2001:283). Its collection from prickly acacia trees still provides one of the important cash source for the peoples of particular African countries, such as Sudan and Nigeria.
  • Natural resins present in plants are known as rosins, and they can be hard and brittle, more or less translucent, insoluble in water, but softens in heating (Wickens 2001:247, 285) or can be crude resins, the opaque and sticky material obtained by tapping living pines (Wickens 2001:245). The biological function of resins, gums, and pitch is to seal wounds on a tree, and protect it from disease or insect attacks.
Resin production, Menemen-Turkey 2001, photo taken by F.Ertug.
  • Harvesting exudates from living trees usually leaves distinctive scars – punctures, or cuts in the bark of varying depth depending on the substance being harvested, often coated with pitch – many of which are re-opened year after year (Turner et al in press). Several Pinus and Juniperus species provide resin/rosin and turpentine or tar, which most can be used as medicine to treat humans as well as animals and/or as varnish, coating, adhesive, glue, etc. A very important use of rosins and tars can be waterproofing baskets, bags, hats, shoes, clothes, leather and buildings.
  • An example: Tar can also be extracted from Cedrus, and its distillation requires simple techniques but needs expertise and know-how. In a recent article the details of tar production with traditional methods are given for local uses such as to heal wounds, fight parasites, and cure various diseases in humans and domestic animals (Kurt et al. 2008). As the local people use dry resinous wood from large cedar tree stumps that have been dead for several years, its production is sustainable. For the extraction, two holes (c. 1 m. in diameter and about 1,5-2 m. deep) need to be excavated, one for the ignition, the other for the collection of tar. The inner surfaces of the ignition compartment are plastered with mud and clay to prevent the loss of extracts, and a discharge pipe and an air pole is placed. Then chopped pieces of stump is placed carefully and packed tightly into the ignition compartment. This process requires skill because rapid burning or excess air may reduce both the quality and quantity of tar. Then the top is tightly covered using bulky fresh leaves and/or herbs (in the photos: Marribium globosum), then with a clay–rich mud. After it has fired, the hole is closed, first with herbs, then with mud, and let it burn slowly for a day. After first 5 hours tar starts to drain from the ignition compartment through the discharge channel to the collection compartment.
  • Another study also indicates the importance of tar in the inner Taurus Mountains, Turkey: the Coniferae tars are sometimes called collectively as 'kara hekim' (black doctor), referring to their dark color and healing property (Yesilada et al. 1995).
Tar production 1: Chopping Cedar stump into pieces, while the two holes excavated in the background, Elmali, Antalya, Turkey, 2005, photo taken by Y.Kurt. With the permission of the author.
Tar production 2: Pieces of Cedar is carefully placed into clay plastered hole, Elmali, Antalya, Turkey, 2005, photo taken by Y.Kurt. With the permission of the author.
Tar production 3: The top is closed with fresh herbs, Elmali, Antalya, Turkey, 2005, photo taken by Y.Kurt. With the permission of the author.
Tar production 4: The pile is plastered, and ignited to burn slowly for draining the tar, Elmali, Antalya, Turkey, 2005, photo taken by Y.Kurt. With the permission of the author.

Dye plants

Traditional dye plants which were used to dye wool and other vegetable fibers are numerous, but the number of cultivars used worldwide is quite limited. Among the most important and oldest dye plants we can mention the woad (Isatis tinctoria), dyer's rocket (Reseda luteola), madder (Rubia tictorum), safflower (Carthamus tictorius) and indigo (Indigofera tictoria) for the South West Asia and the Mediterranean basin (Böhmer 2002; Zohary and Hopf 2004). All these plants cultivated, traded and used for thousand of years, until the end of nineteenth century, in addition to local species collected from wild. Cardon (2007) explores 300 plants and 30 animals (marine molluscs and scale insects) used as natural dye sources worldwide. Various analysis methods developed to identify the dyes used in ancient textiles (see Kirby 2008; http://www.arts.gla.ac.uk/SESLL/EngLang/ihsl/projects/ASPNS/bib12.htm).

An Anatolian flour sack, dyed with traditional vegetable dyes such as madder and indigo, Turkey, F. Ertug.
  • Usually not only dye plants, but mordans (minerals and/or plant parts to fix the color or activate dyeing) were also collected from wild. Cupules of acorns were among the most well known mordants used in dyeing. Various lichens, berries and skins of onion, walnut fruits, barks of various trees can be used in dyeing.
  • Main colors provided from vegetable dyes were red (especially the red of madder was highly appreciated), blue (e.g. woad and indigo), and yellow (e.g. safflower, dyer's rocket). Many shades of reds (from pink to dark reds), blues, purple and green can be provided by using less and more plants or by arranging the boiling time or mixing with other plants, minerals.
  • Dyeing usually imply the dying of fibers, however woven cloths can also be dyed, and/or printed with various vegetable dyes. Block printing and ikat are techniques commonly used throughout Asia. Some gums, such as Gum Arabic is used in block printing both as thickening agent and also to fix the colors to the cloth.
  • for more information on dyeing plants see:
  • http://www.arts.gla.ac.uk/SESLL/EngLang/ihsl/projects/ASPNS/bib12.htm
  • http://www.pfaf.org/database/search_use.php?K[]=Dye
  • http://www.plantcultures.org/plants/indigo_production__trade_indigo_as_a_new_crop.html
  • http://www.faculty.ucr.edu/~legneref/botany/tandye.htm#barkdyes

Other uses

Environmental uses, such as soil erosion, shade providers, windbreaks, hedge plants, ornamentals, pollution indicators (e.g. some mosses, liverworts can indicate airpollution; some Typha species indicate salt concentrations in water) can be considered among various other uses of plants. Some remove impurities from water, e.g. water hyacinth (Eichhornia crassipes), and some others e.g. Moringa species are used to purifying water in some countries (Wickens 2001: 399).

  • The evidence of the use of aromatic plants, oils, and minerals either as insecticides or repellents is frequently mentioned in antique sources (e.g. in Egypt, Ebers Papyrus of c. 1600 BC), and some direct evidence of their use in storage areas has been detected as early as Late Bronze age (Panagiotakopulu et al 1995). Aromatic plants such as coriander, laurel, annis, marjoram (Origanum vulgare) were among those, and the presence of leaves of Thymelaea cf. hirsuta consistently in all samples from pithoi in prehistoric Santorini suggests its deliberate addition to stored crops (ibid:708). Ethnobotanical and ethnographic works provides evidences for similar uses, and teaches us when and how these insecticides and repellents worked (Halstead 1990).
  • Bee food plants are also important for providing pollen and nectar. Food for silkworms provided from white mulberry (Morus alba).

References (food & diet)

  • Binford 2002
  • Bottéro 2004
  • Caplan 1997
  • Curtis 2001
  • Dalby 2002
  • Duin and Sutcliffe 1992
  • Ertug 2000a
  • Ertug-Yaras 1997
  • Evers and Nesbitt 2006
  • Finkel and Seymour 2008
  • Freedman 2008
  • Gosden 1999
  • Jones and Valamoti 2006
  • Halstead 1998
  • Harris and Hillman 1989
  • Hastorf 1991
  • Hillman 1985
  • Jacomet 2008
  • Kislev and Bar-Yosef 1988
  • Kramer 1982
  • Lee 1965
  • Levi-Strauss 1970
  • Lewington 2003
  • McGee 2004
  • Mears and Hillman 2008
  • Miller 1996
  • Molleson 1994
  • Munson 1989
  • Nadel et al 1994
  • Oeggl 2009
  • Palmer 2002
  • Palmer and van der Veen 2002
  • Pieroni 1999
  • Pretty 2007
  • Price and Ogle 2008
  • Samuel 2004
  • Sarpaki 2001
  • Savard et al 2006
  • Sigault 1988
  • Soffer, Adovasio, and Hyland 2000
  • Swetnam 1984
  • Turner 2005
  • Turner 2006
  • Turner et al. in press
  • Valamoti 2007
  • van der Veen 2003
  • Wickens 2001
  • Zohary and Hopf 2004

References (plants)

  • Anderson and Ertug-Yaras 1998
  • Barber 1991
  • Baytop 1999
  • Beauclair et al 2009
  • Berlin and Berlin 2005
  • Bichard 2008
  • Biran et al 2004
  • Boserup 1989
  • Böhmer 2002
  • Cardon 2007
  • Curtis 2001
  • Dufraisse 2006
  • Duin and Sutcliffe 1992
  • Ertug 2003b
  • Ertug 2004
  • Ertug et al 2004
  • Ertug-Yaras 1997
  • Etkin and Ross 1982
  • Finkel and Seymour 2008
  • Gradé 2008
  • Hanlidou et al. 2004
  • Heiss and Oeggl 2008
  • Halstead 1990
  • Halstead 1998
  • Halstead and Tierney 1998
  • Jacomet 2008
  • Jones and Halstead 1995
  • Kirby 2008
  • Kislev and Bar-Yosef 1988
  • Kramer 1982
  • Kuhnlein and Turner 1991
  • Kunzig 2002
  • Kurt et al. 2008
  • Mabey 1988
  • Mason and Nesbitt in press
  • Meier 2004
  • Merlin 2003
  • Miller 1996
  • Nadel et al 1994
  • Oeggl 2009
  • Panagiotakopulu et al 1995
  • Pieroni et al 2002
  • Pyramarn 1989
  • Rasmussen 1990
  • Sarpaki and Asouti 2008
  • Schick 1988
  • Smith-Oka 2008
  • Soffer et al. 2000
  • Turner et al. in press
  • Valamoti and Charles 2005
  • Wickens 2001
  • Yesilada et al. 1995
  • Zohary and Hopf 2004