CHAPTER 4

FLOWERS AND FOLIAGE

HONEY

Honey is a sweet, viscous, golden coloured liquid that is “manufactured” by different species of honeybees, such as Apis mellifera, from the nectar of flowers. It is stored in wax combs and used by the bees as a food source to feed both immature larval stages and adult bees during winter. Approximately 120 000 bees are required to produce 1 kg of honey and a single bee will produce only about a tablespoon of honey during its lifetime [Thomas and Schumann, 1992].

Honey is also the oldest sweetener known to humans and has been an eagerly sought commodity since prehistoric times. Primitive societies hunted for trees where bees stored honey so that they could obtain a supply of the precious sweetener. Eventually beekeeping or apiculture, the science and art of raising bees in artificial hives, where honey can easily be harvested evolved and today is a major agricultural industry. Modern beekeeping not only provides a supply of a natural sweetener but, more important, makes large numbers of bees available when agricultural crops that depend on insect pollination for production of fruits, nuts and seed are in flower. This is an important agricultural industry because about one-third of the human diet is derived from insect pollinated plants and honeybees are responsible for 80 percent of the pollination [National Honey Board, 1998].

FORMS OF HONEY

Honey can come in a variety of forms. The most common is liquid honey that is extracted from the honeycomb by centrifugal force, gravity or straining. Liquid honey is the most convenient form of honey for cooking or baking and most honey is sold in this form. Creme or spun honey is brought to the market in a crystallised state. The crystallization is controlled so that, at room temperature, the honey can be spread like butter. In many parts of the world, creme honey is preferred to the liquid form. Comb honey is honey that comes as it is produced in the hive, in a honeybee’s wax comb. The comb, as well as the honey, is edible. Cut comb honey is honey that has been packaged with chunks of the honeycomb [National Honey Board, 1998].

RELATED PRODUCTS

Related products of honey production are beeswax, bee pollen and royal jelly. Beeswax is sold as a by-product for candles, polishes and as an ingredient in cosmetics. Royal jelly, the secretion of the glands of worker bees, is the queen bee’s sole source of nourishment and is promoted as a nutrient for human consumption and energy source. Bee pollen is in demand in Japan as an aphrodisiac [Thomas and Schumann, 1992].

NECTAR SOURCES

The flowers of many plants, including trees, are excellent sources of nectar for honey. The colour and flavour of honeys differ depending on the nectar source visited by the honeybees. The colour ranges from nearly colourless to dark brown and the flavour varies from delectably mild to distinctively bold, depending on where the honeybees worked [National Honey Board, 1998].

The properties of ideal bee forage are the production of large amounts of honey. Flowers must not only produce large amounts of nectar but the nectar must be accessible and produced at the correct time of the year. Moreover, the honey should have a pleasing colour and flavour and be slow to crystallize. In some areas of the world, where finely granulated honey is used, the latter characteristic is of little consequence. However, in the United States where liquid honey is the primary form consumed, it is a valuable attribute [Ayers, 1992].

The flowers of many temperate broad-leaved trees are excellent nectar producers and are capable of producing yields that equal or exceed certain herbaceous plants that are known to be good honey producers (Table 4.1). Up to 40 species of hardwood trees have been listed as important nectar sources in the United States [Jones et al., 2002]. Wild honeys from temperate broad-leaved trees are locally important non-wood forest products in many parts of the world. They often provide a supplemental income source for rural people, and beekeeping is a popular hobby in some countries. Each “wild” honey has its own distinct colour and flavour. In general, lighter coloured honeys are milder in flavour while darker coloured honeys are bolder [National Honey Board, 1998]. The characteristics of honeys obtained from representative temperate broad-leaved trees are described in the following sections.

Table 4.1 Honey production potentials of two temperate broad-leaved trees compared to several herbaceous plants with good reputation as honey producers

Source: Ayers 1992

Eucalyptus spp.

Eucalypts are an important source of honey in Australia, where these trees are native, as well as places where they have been introduced. There is a distinctive flavour to eucalypt honey and between the honeys produced from various species of this genus. These are often kept separate by producers and shopkeepers to meet the demands of customers who have favourite flavours. Jacobs (1979) describes the characteristics of pollen, nectar and honey produced by 36 species of Eucalyptus.

The value of plantation eucalypts as a source of honey is being recognized in many countries where various species are widely planted. Plantations often produce far more flowers than do the native eucalypt forests in Australia [Jacobs, 1979].

A unique use of eucalyptus honey is the preparation of the liqueur, eucalittino, by the Trappist monks at the Basilica delle Tre Fontane (Three Fountains) in Rome, Italy. This liqueur has been prepared and sold at the Tre Fontane for more than 100 years [Jacobs, 1979].

Castanea sativa

The flowers of the European chestnut produce a flavourful honey. Miele di Castanea is a popular item in speciality food shops in Italy and other European countries. Beehives are often kept in chestnut stands and orchards during the flowering period and provide a supplemental income source for people who own orchards or natural forests of this tree [author’s observation].

Liriodendron tulipifera

The tulip poplar is native to eastern North America and has large greenish-yellow flowers that generally bloom in May. Tulip poplar honey is produced from southern New England to southern Michigan and south to the Gulf States east of the Mississippi River in the United States. This honey is dark amber in colour. However, its flavour is not as strong as one would expect from a dark honey [National Honey Board, 1998].

Nyssa ogeche

This locally popular honey is made from the flowers of the Ogeeche tupelo (Nyssa ogeche), a tree that grows profusely along the Apalachicola, Choctahatchee and Ochlockonee Rivers and their tributaries in northwestern Florida, United States. Tupelo trees have clusters of greenish flowers, that later develop into soft, berry-like fruits. Tupelo is a leading honey plant in this region, producing tons of honey during April and May. The honey has a mild, pleasant flavour and will not granulate. To gather the nectar to produce this unique speciality honey, bees are placed on bluffs or elevated platforms along the river’s edge during April and May. These river valleys are the only places in the world where tupelo honey is produced commercially.

Tupelo honey is a light golden amber colour with a greenish cast. The flavour is delicate and distinctive. Due to its high fructose content, tupelo honey will never crystallize (granulate). Tupelo honey is more expensive than most honeys because it costs more to produce. To gain access to the river location near the tupelo trees requires expensive labour and equipment. In order to ensure the honey is pure tupelo, the bee colonies must be stripped of all stored honey just as the white tupelo bloom begins. Then, the new crop must be removed before the bees can mix it with honey from other sources [National Honey Board, 1998]. One apiary in Florida has a special use permit to place over 2 000 hives in the Appalachicola National Forest for production of tupelo honey [Thomas and Schumann, 1992].

Prosopis spp.

In the southwestern United States and Mexico, the flowers of mesquites (Prosopis glanulosa and P. pubescens) are excellent sources of honey. In Arizona, mesquites are rated by beekeepers as the most valuable plant for honey production. Beehives on the Fort Yuma and Cocopah Indian Reservations are often kept in mesquite forests when the bees are not being used to pollinate agricultural crops [Miller, 1997].

The flowers of P. tamarugo and P. chilensis are locally important sources of honey in the arid northern parts of Chile. Bloom occurs during August, September and part of October. Annual production of Prosopis honey averages 9.8 kg/beehive [Garfias Salinas et al., 1995].

Robinia pseudoacacia

This medium to large tree, which is native to the eastern United States, produces large clusters of white flowers that are an excellent nectar source. Honey produced from this tree is of a light golden colour and ranks among the lightest of honeys. It is also exceptionally slow to crystallize [Ayers, 1992]. Black locust honey is popular both in the Unites States and in parts of Europe where this tree has become naturalized [author’s observation] (Figure 4.1).

Figure 4.1 Flowers of honey producing temperate broad-leaved trees. Top, black locust (Robinia pseudoacacia). Bottom, European linden (Tilia cordata).

Figure 4.1 Flowers of honey producing temperate broad-leaved trees. Bottom, European linden (Tilia cordata).

Tilia spp.

Several species of lindens or basswoods are popular sources of honey in Europe and North America. This honey is water white in colour and is often characterized by its distinctive biting flavour. The flowers are cream-coloured and they bloom in late June and July [National Honey Board, 1998].

Other broad-leaved temperate trees that are good honey sources include maples (Acer spp.), service berries (Amalachier spp.), alders (Alnus spp.), various species of wild cherry (Prunus spp.) and willows (Salix spp.) [Thomas and Schumann, 1992]. The flowers of the sourwood (Oxydendrum arboreum) are a popular honey source in the southern Appalachian Mountains [Wigginton, 1973] (see Box 4.1).

PRODUCTION AND TRADE

According to data from FAO, world honey production exceeds 1.1 million t/a and is increasing. This includes honey from all nectar sources (agricultural plants, wild flowers and forest trees). China, Mexico, Russia, Turkey and the United States are among the major honey-producing countries accounting for approximately 55 percent of world production. World trade in honey currently averages 300 000 t/a and exports have been rising steadily since 1975. Germany, Japan, the United Kingdom and the United States are the major markets for honey [Iqbal 1993].

Updated information on production and trade of honey can be obtained from the International Bee Research Association (http://www.cf.ac.uk/ibra) or from the Bees for Development Web site: http://www.planbee.org.uk.

LEAF OILS AND FLAVOURINGS^[5]

EUCALYPTUS OILS^[6]

The genus Eucalyptus (Family Myrtaceae) is native to Australia and some islands to the north of it and consists of over 500 species of trees. These grow under a wide range of climatic and edaphic conditions in their natural habitat. Eucalypts vary in form from low shrubs and multi-stemmed trees less than 10 m in height (mallees) to large single-stemmed trees more than 60 m tall.

Nearly all species of eucalypts have glands in their leaves that produce oils and give the leaves of this group of trees their characteristic odour. These oils are “essential oils” and comprise a range of natural oils that collectively give eucalypt leaves their odour but can be differentiated into separate chemicals that are of value in various industries.

Figure 4.2 Honey produced from the flowers of black locust, Robinia pseudoacacia. In Italy it is marked as Acacia honey.

Types of oils and uses

The primary essential oils derived from eucalypts are:

Several hundreds of species of eucalyptus have been shown to contain volatile oil, though probably fewer than 20 of these have ever been exploited commercially for oil production. Today, fewer than a dozen species are utilized in different parts of the world, six of which account for the greater part of world production of eucalyptus oils. Those species currently exploited, the percentage of oil in their leaves, the composition of the oil, their uses, as well as the countries in which they are utilized, are listed below. Other species that have been used in the past include E. cinerea (medicinal), E. cneorifolia (medicinal) and E. macarthurii (perfumery).

The value of eucalyptus oil for medicinal purposes lies in its cineole content, which largely determines, also, the price that it fetches. Chinese oil, for example, is commonly traded as "eucalyptus oil 80 percent", referring to the fact that it contains at least 80 percent cineole. In early 1994 the price of standard grade Chinese 80 percent eucalyptus oil had fallen below US$ 3/kg from the US$ 6/kg level in 1989.

The medicinal type of oil is used as an inhalant or chest rub to ease breathing difficulties, as a mouthwash in water to refresh or ease the throat, and as a skin rub to provide relief from aches and pains. Eucalyptus oil is also used as a general disinfectant, cleaner and deodorizer about the house.

For the perfumery oils, aroma characteristics are important. According to published standards for E. citriodora oil, the aldehyde content calculated as citronella should be less no less than 70 percent. Eucalyptus citriodora is the major of the two principal perfumery oils. It differs from the medicinal oils in containing citrinellal, rather than cineole, as the major constituent. The oil is employed in whole form for fragrance purposes, usually in lower cost soaps, perfumes and disinfectants, but also as a source of citrinellal for the chemical industry. The citrinellal obtained by fractionation of the crude oil may be used as such as an aroma chemical or converted to other derivatives intended for fragrance use. The only other perfumery oil produced in any quantity is that from E. staigeriana. No single chemical predominates in the oil and it is used in whole form for perfumery purposes. It has a lemon-type character.

In countries where eucalypts have been planted, E. globulus has been the main commercial source of essential oils. Its leaves yield about 1 percent of cineole and eudesmol and this can be considered an adequate return if a massive quantity of leaves can be obtained following tree harvesting operations.

Yields of oil from leaf vary somewhat between species but, on a commercial scale, are of the order of 1 percent on a "fresh" basis. Of more relevance to the economics of production is the yield of oil per ha and this is dependent on the biomass production, as well as the oil yield from the leaf. Production from E. smithii in Swaziland yields approximately 15 t/ha of leaf, corresponding to about 150 litres/ha of oil.

There may also be marked differences in oil yield and quality within a species according to the provenance origin of the seed. E. camaldulensis, for example, has a very wide distribution in Australia, but only certain northern Queensland provenances (Petford, in particular) yield an oil, which makes the species attractive as a source of medicinal oil. In extreme cases, in their natural habitat even trees within the same provenance may produce oils, which are quite different to each other. E. dives is a well-known example and it is possible to obtain seed from cineole and piperitone variants.

Those species of eucalyptus which respond well to coppicing may be grown specifically for oil on a short-rotation cycle. In Swaziland, where oil is obtained from E. smithii, the first cut is made 20-24 months after planting. Subsequent cuts of the coppice regrowth are made at approximately 16-month intervals, at which time the plants are 5-6 m tall. Harvesting may continue for many years and in Swaziland some areas of E. smithii are still being harvested after 20 years or more.

Table 4.2 Eucalyptus species used for essential leaf oils

¹ The use of parentheses indicates a minor producer.
Source: Coppen, 1995; Jacobs, 1979.

There exists mechanical harvesting of E. polybractea in Australia. This system of harvesting was developed in Australia as a means of reducing labour costs and is used to harvest natural stands of E. polybractea. The frequency of harvesting is between 18 and 24 months, at which time the shrubs are about 1 m high.

Production and trade

The essential oils derived from Eucalyptus are classified in the trade into three broad types according to their composition and main end-use: medicinal, perfumery and industrial. The medicinal types are the most important ones in terms of volume of production and trade.

Plantation eucalypts dominate world production and trade in eucalyptus oils. During the period 1970-1974, only 8.8 percent of the world production came from natural forests in Australia. World production and trade in eucalyptus oils are dominated by the People's Republic of China, which is the largest producer of both cineole-rich medicinal oils (about 70% of world output and trade) and perfumery oil (from E. citriodora). During the period 1993 to 1997, Chinese exports of eucalyptus oil averaged approximately 3 800 t/a, with an average annual value of US$ 11.9 million [Coppen, unpublished). Furthermore, several importing countries such as Portugal, Spain and Australia are also producers and processors of eucalyptus oils and re-export much of what they import.

Total world production of medicinal-type eucalyptus oil in 1991 has been estimated at around 3000 t, of which approximately 2 000 t were exported [Coppen and Hone, 1992]. Production and exports of E. citriodora oil, the main perfumery oil, for 1991 are estimated at about 1500 t and 500 t, respectively. Globally, the European Community is the largest importer of eucalyptus oils. Production of E. citriodora oil is also dominated by the People's Republic of China. In 1991 it is estimated that the country accounted for approximately two-thirds (1 000 t) of total production, of which perhaps 400 t were exported. Brazil (500 t/a) and India (50 t/a) are the only other producers of this type of oil, with Brazil exporting about half of its production. Brazil is the only supplier to the world market of E. staigeriana oil; production is of the order of 60 t/a.

Within Europe, France, Germany and the United Kingdom are the major markets for eucalyptus oil-based products. In 1990 their combined imports amounted to 1 840 t. Imports into the United States, the largest single country market for eucalyptus oils (excluding the People's Republic of China and those countries, which re-export much of their imports after further processing).

Southern Africa is a major producing region for eucalyptus oil, most of it from South Africa but a significant proportion from Swaziland. In South America, Chile and Brazil are the major producers, with smaller amounts coming from Bolivia, Uruguay and Paraguay. In recent years, Chile has exported between 47 t/a and 144 t/a of essential oils, primarily from E. globulus (extensive eucalypt plantations) (Table 4. 2) [Garfias Salinas et al., 1995].

Table 4.3 Exports of eucalyptus oils from Chile 1987-1992

Source: Garfias Salinas et al., 1995.

During the same period, the leading producers of eucalyptus leaf oils were countries with Mediterranean climates. Portugal and Spain accounted for 44.2 percent and 12.4 percent of global production, respectively [Jacobs, 1979].

BAY LAUREL

Laurus nobilis (Family Lauraceae), known as bay laurel, sweet bay or laurel, is an evergreen shrub or small tree, indigenous to the Mediterranean Basin and the Near East. This plant has been admired for its beauty and aromatic leaves since Greek and Roman times (see Chapter 2).

Figure 4.3 Grading of dried bay leaves in Turkey (photo by G. Allard).

The dark green leaves of bay laurel are fragrant and aromatic. After drying, they are broken, cracked or cooked to release their characteristic aroma and flavour. Dried laurel bay leaves are used as flavouring in soups, fish, meats, stews, puddings, vinegars and beverages. Oil of bay or oil of laurel leaves is an essential or volatile oil obtained by steam distillation of bay leaves and oleoresin has replaced the dry leaves in some food preparations.^[7]

The oil of laurel reaches a content of 1-3 percent on a fresh weight basis. The main constituents of this oil are 1,8-cineole, pinene, sabinene, 1-linalool, eugenol, eugenol acetate, methyleugenol, 1-terpinol acetate, phellandrene, other esters and terpenoids. This oil is generally recognized as being safe for human consumption as a spice, natural flavouring and essential oil extract and is used by the cosmetics industry for creams, perfumes and soaps.

The leaves and berries of Laurus nobilis have also been used for treatment of rheumatism, skin rashes, earaches and other medical problems. Further, they are also used as an insect repellent.

Bay leaves are collected from both cultivated and wild plants in many Mediterranean countries. Commercial production centres in the Mediterranean basin include portions of Algeria, France, Greece, Morocco, Turkey and Portugal and Spain (minor producers). Outside the Mediterranean Basin, bay leaves are produced in the Canary Islands, Central America, Mexico and the southeastern United States [Simon et al., 1984].

MINOR LEAF OILS

The foliage of several other species of plants of the family Lauraceae has aromatic foliage. The myrtlewood or California laurel (Umbellularia californica) (Figure 4.4), a tree indigenous to southwestern Oregon and northern California, was used as a substitute for bay leaves (Laurus nobilis) by the early European settlers in the region [Hora, 1981; Ciesla, 1990b]. An essential oil extracted from this tree contains umbellulone and has been used both as an insecticide and as a condiment. This oil is a mucous irritant and has shown some toxicological properties (see Box 4.2). Myrtlewood oil also contains safrole, a compound that has been shown to have carcinogenic and hallucinogenic properties [Simon et al., 1984].

The dried, ground leaves of American sassafras (Sassafras albidum) are known as file gumbo and are used in traditional Creole or Cajun dishes both for their flavouring and thickening properties [Harlow and Harrar, 1950; Hora, 1981; author’s observation]. Sassafras leaves do not contain safrole, a carcinogen that is found in the roots and bark of the tree and are safe for human consumption.

The aromatic foliage of Pemus boldus (common name, boldo), a tree which occurs in the mountain ranges of central Chile, is rich in alkaloids, flavinoids, tannin, citric acid and related products. Branches containing foliage are harvested with a machete and placed in a shady, clean place to dry for two to three days before the oils are extracted [Garfias Salinas et al., 1995]. The foliage is also the source of an herbal tea which is popular in Chile [author’s observation].

Figure 4.4 The foliage of the Oregon myrtlewood (Umbellularia californica) is aromatic and has been used as a substitute for foliage of Laurus nobilis as flavouring for soups and stews. However, its principle oils constituent, umbellulone, has been shown to be a mucous irritant and has some toxicological properties.

YERBA MATÉ

Yerba maté is a species of holly, Ilex paraguariensis (family Aquifoliaceae), which occurs in the subtropical/warm temperate forests of southern Brazil, Uruguay Argentina and Paraguay. The evergreen foliage of this plant (Figure 4.5) is harvested, dried and ground into a fine powder and is used as a tea. Yerba maté is a popular regional beverage and the foliage is harvested either in small plantations or from natural forests where this plant grows.

Yerba maté has a characteristic mature flavour similar to that obtained from tea (Camellia sinensis). The flavour can be described as sweet, bitter, withered leaf-like, and alfalfa-like. The herb contains A, C, E, B1, B2, B complex; carotene; riboflavin; pantothenic acid; biotin; and vitamin C complex. Moreover, it has 15 different amino acids, plus significant amounts of magnesium, calcium, iron, sodium, potassium, manganese, silicon, phosphates, zinc, niacin, sulphur, and chlorophyll, choline and inositol.

To the Guarani Indians, yerba maté is known as the “drink of the gods”. They used it for medical purposes such as to boost immunity, cleanse and detoxify the blood, tone the nervous system, combat fatigue, reduce stress and stimulate the mind. Still today, tens of millions of South Americans use yerba maté for its medical properties.^[8] The plant has stimulant properties and is supposedly beneficial for headaches, migraine, neuralgia and insomnia. Its stimulant principle is caffeine but it has a lower caffeine content than either tea of coffee [Hora, 1981; Lust, 1990]. Yerba maté is usually sipped from a traditional gourd-like cup, made of wood, with a built-in drinking straw, bombilla, a silver straw with a bulbous filter at its lower end that prevents the leaves from entering the tube (Figure 4.6) [author’s observation]. The gourds can range from simple calabashes to carved wooden or silver vessels, some of which have become museum pieces (Berhardson 1996). People can be seen drinking this traditional beverage as far as the Argentine Patagonia, far from the natural range of Ilex paraguayensis (author’s observation).

Figure 4.5 The foliage of the yerba maté (Ilex paraguariensis) is used in a tea that is a popular regional beverage in southern Brazil, Uruguay, Argentina and Paraguay.

Figure 4.6 Yerba maté is usually drunk from a traditional cup, made of wood, with a built-in drinking straw.

Yerba mate became commercially important during the colonial era on plantations of Jesuit Missionaries established on the upper Parana River. Today, Argentina is the world’s largest producer and consumer of mate. Argentines consume an average of 5 kg per person per year, more than four times the average intake of coffee. In Argentina, yerba maté was first grown in experimental plantations in 1903. Cultivation has expanded considerably and during the 1991/92 season, production was 482 000 t with an average yield of 1 800-2 400 kg/ha. Areas where yerba maté production is an important part of the economy include Misiones Province and the northeastern portion of Corrientes Province. The value of the mate production in Argentina was estimated at US$ 80 million, with exports of maté at approximately US$ 28 million for 1998 [Résico, 1995, 2001].

DECORATIVE FOLIAGE

The foliage of many species of temperate broad-leaved trees used in various kinds of home floral decorations and the harvesting of several species provide a supplemental income for rural people.

The foliage of deciduous broad-leaved trees and shrubs is not as durable as the foliage of conifers or evergreen broad-leaved species and cannot be transported for long distances. However, the foliage of some species is locally important. In Germany, for example, the branches and foliage of the North American red oak (Quercus rubra), a tree widely planted in some parts of central Europe as a timber producing species, is considered to be a speciality product and is available for sale in some floral markets for home decorations [Ehlers, 1968; Rau, 1969]. Gathering the foliage of deciduous foliage of broad-leaved trees and shrubs for home decoration is often a popular recreational activity both in Europe and North America, especially in autumn when the foliage of many species turns brilliant colours.

In British Columbia, 19 floral greenery products, generated from more than 30 species of forest plants, are identified. Examples include shrubs like Gaultheria shallon (salal), Caccinium ovantum (evergreen huckleberry), Berberis nervosa (Oregon-grape) and Xerophyllum tenax (beargrass) [Chamberlain, Bush and Hammet, 1998].

The demand for high-quality beargrass (Xerophyllum tenax) has increased. The highest grade beargrass (darkest leaves) grows in areas with overstorey tree canopy closure greater than 60 percent while the most productive plants produce the lowest grade beargrass, and grow in areas with less than 30 percent overstorey tree canopy closure.^[9]

These floral greens are important to the economy of the Pacific Northwest. For instance, the regional sale of salal green reached US$ 13 million, the one of beargrass US$ 11.5 million and evergreen huckleberry amounted to more than US$ 1.7 million in 1989 [Chamberlain, Bush and Hammet, 1998]. In British Columbia, exports of salal account for more that those of mushrooms [Tedder et al., 2000].

In Christian cultures, the spiny, dark green foliage and brilliant red berries of the American holly (Ilex opaca) and the European holly (I. aquifolia) are used in the production of Christmas wreaths and garlands. The foliage of I. opaca, a tree that has a natural range throughout much of the eastern United States, is harvested primarily from natural forests. In the Pacific Northwestern states (Oregon and Washington), plantations of the European I. aquifolia have been established. During the 1930s and 1940s, harvesting of holly foliage was so heavy and damaging to trees in natural forests along the Atlantic coast of the United States that I. opaca was practically eliminated from the northern part of its range [Panshin et al., 1950].

The foliage of some species of Eucalyptus dries well and is popular additions to floral arrangements. The evergreen leaves and branches of Laurus nobilis, a Mediterranean species, are used in garlands and wreaths [Simon et al., 1984].

MINOR AND TRADITIONAL USES OF FOLIAGE

The stiff, spiny foliage and branches of holly (Ilex spp.) were once used in Europe by chimney sweeps [Hora, 1981].

The foliage of several species of elms (Ulmus spp.) was once the preferred feed for cattle over large areas. The use of this foliage was frequently mentioned by Roman agricultural writers and persisted in parts of Europe until the early 1900s. The use of Ulmus wallichiana foliage as a cattle feed is still important today in the Himalayas [Hora, 1981]. Even now, in many developing countries, foliage of several temperate broad-leaved tree species is cut and dried during the summer for use as cattle feed in the winter (Figure 4.7).

The leaves of Crataegus laevigata, a small tree native to Europe and North Africa were used in a leaf infusion tea to reduce high blood pressure. The leaves of this tree were also used as a substitute for tobacco [Hora, 1981].

Figure 4.7 Temperate broad-leaved trees (including species like Querqus castaneifolia, Fagus silvatica, Acer spp., Carpinus spp. and Ulmus spp.) with their branches looped for fodder (Elbrouz Mountains in northern Iran). The branches are cut in the summer, dried and tied as fodder along the tree stem for feeding cattle during the winter (photo by P. Vantomme).

Willow (Salix spp.) foliage contains salicin that becomes salicylic acid in the human body and is the principal ingredient in aspirin (see Chapter 6). The foliage can be chewed to relieve minor pain and fever [Lust, 1990].^[10]

Figure 4.8 Severe degradation of a temperate broadleaf forest (in which all remaining trees have their branches regularly cut-off for fodder) in northern Iraq (photo by M. Malagnoux).