The back is characteristically marked by a pair of small dark brown spots on the lower back and another pair of markings on the shoulders. Dorsal coloring is reddish, hence the common name of Red Toad. The ground color is pale brown and even pinkish at times. The flanks are either pale or very dark. The underside is speckled with gray (Channing and Howell 2006).
The tadpole has an unusual horseshoe-shaped flap of skin on the head (Channing 2001).
The specific name carens is Latin for "lacking" and refers to the lack of parotoid glands (Channing and Howell 2006). Other common names include the Red-backed toad, African split-skin toad, kazoli in Lwena and Manganja, conga in Sena, naliwonde in Yao, rooiskurwepadda in Afrikaans, and zonde in Chewa.
Biochemical evidence suggests that S. carens has been separated from other toads evolutionarily for approximately 55 million years (Channing 2001).