Siphocampylus sulfureus is a species of plant in the family Campanulaceae.

It grows as an annual herbaceous shrub to 3 m (occasionally 4 m) tall.

It has tubular yellow flowers arranged in whorls around the vertical stems.

The flowers emit a pungent musky smell reminiscent of foxes, particularly at night.

In daytime, white-throated hummingbirds (Leucochloris albicollis), Brazilian rubies (Clytolaema rubricauda) and purple-breasted plovercrests visit the flowers while at night the tailed tailless bat (Anoura caudifer) visits.