Pentanisia angustifolia is a bushy, herbaceous perennial with terminal umbels of pale blue spring and summer flowers. The plant resprouts annually from a fleshy rootstock when the winter cold disappears.

Lavish blooms on the 40 cm tall plants are eye-catching in the grassland habitat; too often seen in spring on the bare, blackened earth among fresh green blades sprouting after the chronic burning of winter grass. Perennial rootstocks give the plants that have them head start over those that can only reseed after a fire.

Individual flowers in the P. angustifolia flowerhead have long thin blue corolla tubes, opening at the narrow throat into five slender lobes spreading in star-like fashion. Undulations and twisting of these delicate corolla lobes are evident in this picture. The corollas are said often to be covered in down, but this feature is not visible here.

The blue anthers can barely be seen in the flower throats. A few buds are yet to open in the developing umbel. P. angustifolia anthers are sometimes fully exserted (Letty, 1962; Germishuizen and Fabian, 1982; Van Wyk and Malan, 1997).