Impressions of Banana Pseudostem in Iron Slag from Eastern Africa

Abstract

The use of banana plants in the historical iron production industries of several pre-colonial kingdoms of southern and western Uganda has been documented by the presence of banana pseudostem impressions preserved in slag, a waste product of smelting. An investigation into the selection and use of plants within these technologies was undertaken in 2003 in southern Uganda, implementing a new methodology to record the archaeobotanical information contained within the slag. Non-destructive casts of plant impressions were made on-site using a polyvinylsiloxane dental gel. These were then taken to London for further examination, and the casts were identified to the level of plant family, enabling quantitative and qualitative analysis. More recently, archaeometallurgical research in western Uganda in 2007 also revealed the repeated presence of these banana pseudostem impressions in iron smelting slag, confirming that this was an unusual, yet intentional aspect of these localized iron production technologies.

History and conservation of wild and cultivated plant diversity in Uganda: Forest species and banana varieties as case studies

“…Impressions of pseudostems (‘trunks’) of the family Musaceae are preserved in slag associated with iron furnaces of Later Iron date, mostly dating to the 18th or 19th centuries ( Fig. 2 ) ( Iles, 2009 ). They are thought likely to be from banana plants, but Ensete is a possibility (see below).…”

“…2 Archaeological and other sites in Uganda yielding evidence of pre-1900 AD influences of people on forests. Iron smelting areas after ( Iles, 2009 ). The Luganda names of some geographical features are given in italics.…”

Plant use in southern Africa’s Middle Iron Age: the archaeobotany of Mutamba

“…Kahlheber et al 2009), plant exploitation as a part of metal production (e.g. Iles 2009) and plant exploitation and landscape evolution (e.g. Mercuri 2008).…”