The mauve or blue flowers of Plectranthus saccatus var. longitubus live up to the long corolla tube name of the variety. At the corolla tip, the lower lip of the two-lipped flower is large and shallowly bowl-shaped, notched at its tip and the margin variable. The upper lip has three narrowly pointed lobes. At the corolla base there is just a hint of swelling.
The flowers have straight, dark blue pedicels, all pointing to one side of the main stalk of the short raceme. In picture the calyces of the flowers are small, hardly visible. Some P. saccatus plants have white flowers, but it is not known whether this happens in var. longitubus (Pooley, 1998).