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.
A small order remarkable for the curious forms assumed by the seed-vessel of different species. In structural arrangements it hardly differs from the last. The only genus we are familiar with in cultivation is Martynia. The species are of annual duration, branching from the base, and clothed with clammy hairs. Leaves simple, cordate-oblong or rotundate. Flowers large, in short racemes. Corolla campanulate, gibbous below. Fertile stamens 2 or 4. The fruit, at first soft, is ultimately a woody wrinkled 4-celled capsule, terminated by a long curved beak. Seeds few and large. M. proboscidea, Unicorn Plant, has blue flowers; M. lutea, yellow; and M. fragrans has crimson-purple fragrant flowers. All of these are of American origin.