Alchornea cordifolia (Schumach. & Thonn.) Muell. Arg. (Euphorbiaceae), a disjunct Guineo-Congolian tree found in Ethiopia as dominant in riverine forest

Abstract

The small Guineo-Congolian tree Alchornea cordifolia (Euphorbiaceae) has been observed to dominate the undergrowth in an open type of southwest Ethiopian riverine forest not recorded before. The nearest previously known records of this species were at the South Sudan–Congo border and in Uganda and Kenya near Lake Victoria. The newly discovered range extension of A. cordifolia matches that recently discovered for Zanthoxylum gilletii De Wild. (Rutaceae), found as new to Ethiopia in 2006, and is found to be congruent with previous known disjunct distributions of Guineo-Congolian-Ethiopian species. A new account of the genus Alchornea in Ethiopia, including A. cordifolia, is provided in the format of the Flora of Ethiopia and Eritrea.

Keywords:

• Alchornea cordifolia
• disjunction
• Ethiopia
• Euphorbiaceae
• Flora of Ethiopia and Eritrea
• Guineo-Congolian zone
• riverine forest
• Sudano-Zambezian zone

Acknowledgements

We thank the Carlsberg Foundation (Copenhagen) and the Bentham-Moxon Trust (Royal Botanic Gardens, Kew) for financial support of our field work and our travel companions Assefa Hailu and Ermias Getachew for help and good company during the trip. We would also like to thank Gill Challen, Kew, for help during our work with the identification of Friis et al. 14,594 and gathering information about the species.