Heliangelus amethysticollis decolor Zimmer 1951

Zimmer 1951. Studies on Peruvian birds No. 61. The genera Aglaeactis, Lafresnaya, Pterophanes, Boissonneaua, Heliangelus, Eriocnenus, Haplophaedia, Ocreatus and Lesbia. American Museum Novitates, No. 1540 1951: pp. 1-55