The linkage of ancient trade names with the plant species that they probably represent is based on a variety of evidence. Useful information may be provided by morphological and anatomical features, by specific uses of the plant products, and by accompanying descriptions of the area of origin, for example, in references to the import or export status of the trade item in a specific harbor. A second source of information is linguistic evidence, in which both ancient literature and modern Latin nomenclature of plant names are considered. However, the latter should be used with some reservation. In principle, every taxon may be subjected to remodeling, and consequently new names may have been introduced, in which the assignment of plant names is determined by the international code of botanical nomenclature . The scientific plant name is followed by the author citation, referring to the Latin description or diagnosis of the taxon in question. This enables one to judge the status of a specific scientific plant name and also provides a foundation for comparing synonyms. Because the ICBN rules may result in the reuse of existing names for newly defined taxa, linking old trade names with analogous modern scientific plant names may lead to wrong identifications. Cassia, for example,planting blueberries in containers of which the uncurled bark was traded, should not be confused with cultivars from the genus Cassia, including senna and purging cassia , both cultivated for their pods.
Sarcocolla may serve as a second example. Though this brittle resin is still traded in the spice markets of the Near East, its real source is not yet clear. Species belonging to three different genera have been put forward. Some of them are known as “sarcocolla,” yet it has to be realized that Sarcocolla Kunth is a synonym of the currently accepted name Saltera Bullock. Both Penaea sarcocolla and P. mucronata are unlikely suggestions, for their natural distribution area is South Africa. In some instances, two trade items mentioned in literary sources are linked to the same plant species because different names were used for different plant parts or different methods of preparation, resulting in different products . A comparison between the Alexandrian Tariff and the Periplus shows that they have a small quantity of commodities of botanical origin in common. Together, they mention 45 different trade items. Only nine of them are mutual trade items: costus, cassia, aloe, lykion, myrrh, malabathron, long pepper, nard, and aromatics. Plant products mentioned only in the Alexandrian Tariff may include some African plant products that were obtained from alternative trade routes. It is also possible that differences between both written sources are linked to developments in trade, since the Alexandrian Tariff is dated more than 100 years earlier than the Periplus. Two arguments are presented to support this idea. Warmington supposes that amomum or cardamomum, both considered by him as seeds from Elettaria cardamomum, were initially traded exclusively over land routes and only in the second century AD were they imported by maritime trade. This would explain the absence of Elettaria cardamomum in the Periplus and its inclusion in the Alexandrian Tariff.
The predominance of incense products in the Periplus, on the other hand, can be explained by the shift of the Nabataean trade towards full-time specialization in the incense trade at the end of the first century AD According to Johnson , this specialization was a response to the increasing demand for incense in the Roman Empire and the competition for commercial activities in the Red Sea, initiated by the development of an infrastructure of ports, watering stations , and military posts in the Eastern Desert. This would have resulted in a decline in the import of incense via maritime trade. The origin and destination of the 34 plant products mentioned in the Periplus have been summarized in Table 1.2, in which the plant products are clustered into five categories. In the first three categories they are clustered in accordance with their use, whereas the last two categories concern a botanical classification. Some plant products, such as rice and malabathron, were used for a multitude of purposes and have been arbitrarily categorized. For the sake of convenience, information about different harbors is merged per continent, with the exception of Berenike itself. Consequently the letter B indicates that some harbors along the Arabian and Indian coasts exported trade items, whereas others on the same continent imported these items. According to the Periplus, eight different trade items of botanical origin were exported from Berenike to outlets, particularly along the African and Arabian coasts: saffron, olive oil, grapes or olives, wine, grain, cyperus, yellow clover, and storax. In return, harbors along the African coast provided Berenike with makeir and a variety of resins, gums, and bark extracts, whereas exports from the Arabian harbors to Berenike concerned aloe, frankincense, and myrrh.
Items traded from India to Berenike were indigo, long and black pepper, lykion, costus, nard, bdellium, and malabathron. The number of plant products exported via Berenike is far less than the number of imported plant products . This could be explained by the difference in luxury status. Food staples such as oil, grain, and wine were relatively cheap export items in comparison with exotic luxury products such as incense, aromatics, and spices. Furthermore, part of the luxury products was paid with cash money, as was, for example, the case with black pepper . A rich deposit of pottery sherds with written texts was found in the first century dump trench BE97–19 and is contemporary with the Periplus. The ostraka represent several archives, which document customs duties at Berenike and are possibly linked to the transportation of goods between Berenike and Koptos . Commodities that are mentioned are wine, imported from Syria, Italy, and Rhodes; olive oil; vinegar; “fl atbread;” lykion; onions ; beets ; and barley . Plant products that are also recorded by the archaeobotanical analysis of the trash are limited to beets, onions, and an unknown medical herb, which occur in just three ostraka.At its greatest extent, the Roman Empire enclosed an uninterrupted area around the Mediterranean Sea. The northern frontier was bordered by Hadrian’s Wall between England and Scotland and stretched as far as the Rhine and Danube rivers on the Continent. The eastern border ran across territories of modern Turkey, Iraq, Syria, Lebanon, Jordan, and Israel. The extent of the Roman Empire on the African continent was relatively small, with the exception of Egypt . Rome’s southerly expansion in Egypt can be explained by a threefold interest. First of all, the annual flooding of the Nile and the artificial irrigation replenished the minerals on the fields in the Nile Valley and Delta, thus ensuring high yields without exhausting the soil. Due to these conditions, Egypt could feed Rome for four months of the year . In this respect it is important to realize that ancient Rome was an imperial metropolis. According to Rickman the city of Rome had a million residents in the first century AD. A second interest of the Romans concerned the mines and quarries, especially in the Eastern Desert. Important quarries were Mons Porphyrites, Mons Claudianus, and Mons Smaragdus, which produced valuable porphyry, granodiorite and beryl, respectively. Finally, ports along the Red Sea coast could be used by the Romans for long-distance trade in eastern and southern directions. Covering such a large area, the Roman Empire comprised several distinct plant-geographical regions, determined primarily by climate and soil. Taking trees as an example, we can see that the Romans had access to a great variety of economically valued species. In central Europe, both conifers and deciduous trees,container growing raspberries including silver fir and elm , provided excellent wood for furniture and building purposes. Trees with edible fruits, with a predominantly Mediterranean distribution, included the olive , the pomegranate , the stone pine , and the grapevine . In the more southerly Saharo-Arabian region, the date was the important source of highly valued foodstuff. Despite this variety within the Limes , Rome also maintained trade relations with far-flung foreign regions, importing all kinds of exotic commodities, including a wide range of botanical products.As the Roman Empire extended over parts of Europe, Asia, and Africa, foreign trade could penetrate in all three of these continents. Trade routes were developed over land and water, either by river or sea. The most illustrious trade routes in Arabia and Asia became known as the Silk Road, the Incense Road, and the Cinnamon Road, so-called after the most important commodities on those routes.
All these trade routes were much branched and connected with each other . The Silk Road connected old trade centers in the Mediterranean area, such as Antioch and Petra, with those of the Yellow River valley in western China, such as Loyang . The Silk Road branched off in a southern direction to the Ganges Delta in northeast India and to main trade centers in northwest India, such as Barygaza and Barbarikon in the Indus Delta. The exact location of this Barbarikon is still unknown. The Periplus Maris Erythraei, a handbook for merchants describing the commerce between Roman Egypt and eastern Africa, the southern part of the Arabian Peninsula, and India mentions the regular supply of Chinese silk and furs at both these Indian harbors . The eastern part of the Silk Road was also connected with trade routes penetrating into Indochina and Indonesia. Soon after the expansion of the Chinese Empire toward the east during the Eastern Han dynasty the Silk Road connected the Roman Empire and supplied, in addition to silk, spices such as ginger and cassia bark . The Incense Road had its origin in the southern part of the Arabian Peninsula, where both myrrh trees and frankincense trees grew in abundance, and had its main terminal in Petra. According to Pliny , the author of the Natural History in the first century AD, the route from the southernmost located Thomna to Petra was divided into 65 camel stages. Miller refers to the Incense Road as the Frankincense Road, implying that only frankincense was exported from this area. According to the Periplus Maris Erythraei, however, myrrh was not only obtained from Malaô and Mundu along the Somalian coast, but also from Muza along the coast of Yemen . With respect to Muza, myrrh and stacte are explicitly mentioned as local products in the Periplus. Although Pliny states that myrrh from Somalia was more expensive than that from Arabia, the quality of the Arabian myrrh must still have been good as the author of the Periplus advises to bring a considerable amount of money to Muza for this purpose . Miller derives an argument for his opinion from the number of Commiphora species present in Arabia and the Horn of Africa. This is not a convincing argument, however, as production and quality are merely correlated with the abundance of highly esteemed myrrh trees, which might in fact be confined to a single species. Moreover, recent taxonomic studies have revealed that several Commiphora species are native to the southern part of the Arabian Peninsula, its exact number still obscure due to the presence of aberrant forms and intermediates . A more serious objection to the production of myrrh in the Arabian Peninsula is put forward by Wood , who casts doubt on the status of Commiphora myrrha as a source of myrrh, despite its scientifi c name and its bitter taste, and even admits that he never witnessed the collection of resin from any of the Commiphora species that occur in north Yemen. The myrrh that is offered for sale in Yemen today is imported from Somalia and India. It seems, therefore, that in antiquity Somalia was the most likely source of myrrh. The status of the Cinnamon Road is less clear. China, Indochina, Malaysia, India, and Ceylon are the main distribution areas of the genus Cinnamomum, which includes species that yield cinnamon , cassia , and camphor . Cinnamon is native to Ceylon and India, whereas cassia species occur in China , Indochina , Malaysia , and India and Ceylon . The cinnamon species C. tamala also occurs in Indochina . According to Miller , the Cinnamon Road connected China and Southeast Asia via the East African coast with Egypt. Unlike the Silk Road and the Incense Road, this trade route was based on seafaring. It is assumed by Miller that Malayan seafarers reached Madagascar in the second millennium BC.