Notocactus buiningi is one of the most distinctive Notocacti, with a unique bright emerald green body, with many sharp ribs and large yellow flowers that open during the day and close at night.
Morphology: Solitary, flattened cactus.
Stem: Bluish to bright emerald green, up to 8 cm tall and 12 cm in diameter
Ribs: Several, pronounced, and sharp.
Spines: Short, straw–coloured.
Flowers: Very large and showy, shiny, pale yellow with a distinct red-violet stigma
Cultivation: This is an easy plant to cultivate. It likes to be kept cool, and needs only a short rest in winter. It can can tolerate light frost. Grow in full sun or light shade, but it doesn’t like full, hot blazing sun in the central summer months. Water occasionally in winter so the roots do not dry out completely, and water regularly in summer. Some growers suggest to use exclusively rain water. But be careful, as it will rot easily if the substrate is wet and cold. It tends to lose its roots in winter. The root system of this plant is comparatively small, and it is best to grow it in a shallow pot using a neutral to slightly acidic compost, with plenty of extra grit. Give an occasional tonic of sequestrated iron.
Reproduction: Usually by seeds, as it seldom produces offsets.