Plagiosiphon is a genus of plants in the family Fabaceae. It includes five species of trees or shrubs native to west and west-central Africa. They grow in tropical lowland Guineo-Congolian rain forest, often along rivers, on rocky banks, or on hillsides. Four species are limited to Cameroon, Gabon, and Republic of the Congo in west-central Africa. Plagiosiphon emarginatus also grows in Guinea, Sierra Leone, Liberia, and Côte d'Ivoire in West Africa.

Species accepted by the Plants of the World Online as of September 2023:

• Plagiosiphon discifer Harms
• Plagiosiphon emarginatus (Hutch. & Dalziel) J.Léonard
• Plagiosiphon gabonensis (A.Chev.) J.Léonard
• Plagiosiphon longitubus (Harms) J.Léonard
• Plagiosiphon multijugus (Harms) J.Léonard

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