The Andean bellflowers comprise an explosive radiation correlated with shifts to specialized pollination. One diverse clade has evolved with extremely curved floral tubes and is predicted to be pollinated exclusively by one of two parapatric species of sicklebill hummingbirds (
Eutoxeres
). In this study, we focused on the floral biology of
Centropogon granulosus
, a bellflower thought to be specialized for pollination by
Eutoxeres condamini
, in a montane cloud forest site in southeastern Peru. Using camera traps and a pollination exclusion experiment, we documented
E
.
condamini
as the sole pollinator of
C
.
granulosus
. Visitation by
E
.
condamini
was necessary for fruit development. Flowering rates were unequivocally linear and conformed to the “steady‐state” phenological type. Over the course of >1800 h of monitoring, we recorded 12
E
.
condamini
visits totaling 42 s, indicating traplining behavior. As predicted by its curved flowers,
C
.
granulosus
is exclusively pollinated by buff‐tailed sicklebill within our study area. We present evidence for the congruence of phenology and visitation as a driver of specialization in this highly diverse clade of Andean bellflowers.