Accepted name: Incarvillea diffusa
Erect herb to 1 m or so tall. Leaves with 2-6 pairs of leaflets. Leaflets lanceolate to elliptic with pointed tips. Flower clusters of 5-20 flowers. Flowers white or pink. Fruit capsule to 20 cm long, linear, curved.
Himalaya, W China
Two other species, both from China, are occasionally listed: I. delavayi Bur. & Franch., which has 6-11 leaflet pairs and purple, pink and yellow flowers; and I. mairei, which has 4-7 leaflet pairs and flowers mostly deep pink outside and whitish to yellow inside.
Source: (2002). Bignoniaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.