Salvia triangularis is a species of sage commonly called triangleleaf sage. It is endemic to South Africaâ²s Eastern Cape province, where it grows in grass at in altitude, from Qonce (King Williamâ²s Town) to Humansdorp and inland to KwaNojoli (Somerset East) and Keiskammahoek.
Salvia triangularis is a perennial herb, scarcely woody at the base, with slender ascending or scrambling stems up to tall or occasionally longer. Stems are four-angled, bearing long spreading non-glandular hairs below and mainly glandular hairs above.
Leaves are simple, ovate-triangular, about , with a cordate to truncate base and crenate margins; both surfaces are softly hairy, with oil glands present beneath. The petiole is up to or a little over long and hairy.
The inflorescence is simple or branched, with up to ten verticillasters, each six-flowered and widely spaced below. The calyx is tubular, long in flower, expanding to in fruit, and covered with glandular and non-glandular hairs.
The corolla is purple, mauve, or pale blue, about long, with a nearly straight upper lip and a slightly shorter lower lip.
The nutlets are broadly obovate-trigonous, dark brown, and about .
Salvia triangularis flowers from August to October.
It most closely resembles S. aurita but has much smaller leaves and flowers to distinguish it. The smaller flowers also help to distinguish it from S. scabra, and its leaves are entire as opposed to lobed.