The flowers of incarvilleas are large for the size of the plant, and brightly coloured. They are widely flared trumpets, a few to each short stem, in the wild appearing in the summer rain after a dry spring. A few species are shrubby, with more flowers to each stem, but smaller.

Incarvillea mairei var. grandiflora has flowers which are usually solitary, but larger than those of the species. Its habit is also shorter than other Incarvillea, with a scanty rosette of leaves with only 1 or 2 pairs of leaflets. This variety has superb large deep crimson pink trumpet shaped flowers with a yellow tube and handsome white blotches on the throat.