Mapouria spruceana's type collection, Spruce 3343, is represented by a number of duplicates. Most of these specimens are Rudgea sclerocalyx, and Mapouria spruceana was accordingly synonymized with this name by Zappi (in Taylor et al. 2004). However the two duplicates labelled with this collection number at NY do not both represent the same species. One of these specimens is Rudgea sclerocalyx, but the other NY specimen is Appunia peduncularis (Kunth) Delprete. Therefore Steyermark (1967) cited the name Mapouria spruceana in synonymy with both Rudgea laurifolia (now considered a synonym of Rudgea sclerocalyx) and Appunia angulata (now considered a synonym of Appunia peduncularis). Steyermark cited these synonymies without comment, and may have studied these two genera at different times and did not notice that he had simultaneously cited Mapouria spruceana under two different accepted species names. The duplicates of Spruce 3343 deposited in BR, G, M, and P, which are the specimens Mueller might have seen, all are Rudgea sclerocalyx.

C.M. Taylor & S.E. Hirth, 1 December 2016

• Steyermark, J. A. 1967. Rubiaceae. In: B. Maguire & collaborators, The botany of the Guayana Highland—Part VII. Mem. New York Bot. Gard. 17(1): 230–439.
• Taylor, C. M., J. A. Steyermark, P. G. Delprete, A. Vincentini, R. Cortés-Ballén, D. C. Zappi, C. H. Persson, C. B. Costa & E. Anunciação. 2004. Rubiaceae. 8: 497–847. In J. A. Steyermark, P. E. Berry & B. K. Holst (eds.) Fl. Venez. Guayana. Missouri Botanical Garden Press, St. Louis.