Monographs Details: Pithecolobium angustifolium (Rusby)
Authority: Rusby, Henry H. 1927. Descriptions of New Genera and Species of Plants Collected on the Mulford Biological Exploration of the Amazon Valley 1921-1922. Mem. New York Bot. Gard. 7: 205-387.

P. sophorocarpum (?) angustifolium Rusby, Mem. Torrey Club 6: 28. 1896

This plant, originally collected by Miguel Bang, near Guanai, in 1892, has been again collected (no. 1752), at San Buena Ventura, 1,000 feet, November 22,1921, by M. Cardenas, who reports it as " a large tree, with red fruits." The latter specimens agree in every respect with those of Mr. Bang, showing that the differences between it and P. sophorocarpum Benth. are constant over a wide region. I can no longer doubt its specific distinctiveness. The legume consists of about 10 or 12 joints, which are completely separated by short constricted portions. The joints are verrucose, especially before maturing, and all parts of the fruit are ferruginous-tomentellate.