This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Miniature glabrous annuals. Leaves sessile or petiolate, spathulate or orbiculate, entire or 3-lobed. Flowers small, white, violet, lilac, or flesh-coloured, on long peduncles. Sepals spreading, equal at the base. Stamens free. Pouch broadly oblong, laterally compressed, with 2 or 3 seeds in each cell. Only two species are known.
1. I. acaule. - An exceedingly pretty little plant, not more than 3 inches high. Flowers lilac, or white tinged with violet. Native of Portugal.