Like other Stomatiums, these plants form small to medium-sized cushions, which over time often die down from the centre.
The leaves are spatula-shaped to three-angled in cross-section and distinctly broadened towards the tips. The margins usually bear 3-6 (but sometimes up to 18) teeth, whereas the keel is either smooth or decorated with 1-3 teeth.
The flowers appear in September; they open in the evening, are to 22 mm in diameter and have bright yellow petals with red tips.
The plants are found in the southwest corner of the distribution area of Stomatium, on shallow gravel and stony ground in the Sutherland-Laingsburg area, where it can be quite cold in winter.
The pictures were taken in spring and summer, between mid October (#1) and mid January (#4).