I specialize in plant food production systems, past and present. I have previously worked in Canada, the United States, Egypt, and the Near East but have recently focused my attention on the coast of Eastern Africa. In my doctoral dissertation “Swahili Urbanization and Trade: Paleoethnobotanical Perspectives from Pemba Island AD 700-1600,” I examine plant food remains from five Swahili archaeological sites on Pemba Island, Tanzania, in order to track changes that occurred during urbanization and the introduction of Islam. I compared plant food production systems in urban elite households with those from earth-and-thatch houses occupied by the majority of Swahili peoples.

My research revealed that the ancient Swahili relied heavily on African grains prior to approx. 1100 AD, including pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolor), and finger millet (Eleusine coracana ssp. coracana). Asian rice (Oryza sativa) and tree fruits such as coconut (Cocos nucifera) and mango (Mangifera indica), were introduced by 1100 AD and gained rapid acceptance in urban households. Direct dating of plant remains will be conducted in the near future, allowing a more refined chronology of crop use as well as the introduction of Asian taxa and the decline of African cereal crops. The presence of both cereal grains and chaff elements in archaeological contexts confirms that pearl millet and rice were cultivated by the Swahili, and not merely imported into the economy. Moreover, archaeological and archaeobotanical evidence shows a continuation of production practice despite a change in cultivars, namely the maintenance of a household mode of production. This is significant because food production typically becomes specialized and centrally controlled during urbanization, and persistent household production among the Swahili presents a novel example of urban food production apparently developing without centralization. This data shows the retention of some indigenous traditions during Swahili urbanization and the adoption of Islam.

There have been very few archaeobotanical studies conducted in Eastern Africa to date, and very little is known about the indigenous crops and wild resources that the Swahili relied upon. In order to expand our knowledge of these foods, I conducted ethnobotanical research on Pemba Island (2002, 2004). I worked with farmers to understand and document non-mechanized techniques used today in processing of rice, sorghum, and pearl millet on Pemba. Additionally, I collected plant specimens that will help us identify crops, weeds, and wild plants in the archaeological record.

This work is being done in conjunction with the Pemba Archaeological Project, a joint American-Tanzanian program led by Dr. Adria LaViolette (U. Virginia), Dr. Jeff Fleisher (Lehigh University) and Dr. Bertram Mapunda (U. Dar es Salaam). This work is funded by the National Science Foundation (Award to Fritz and Walshaw #043117; Award to LaViolette # 0138319).