This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Coarse diffusely branched glandular-pubescent and viscid strong-scented herbs, with opposite or alternate long-petioled leaves, and large violet purple whitish or mottled flowers in short terminal racemes. Calyx 1-2-bracteolate at the base, campanulate, inflated, unequally 5-cleft, deciduous. Corolla funnelform-campanulate, oblique, decurved, the 5 lobes nearly equal, spreading. Stamens 4 in our species; anthers gland-tipped, their sacs divergent. Ovary i-celled, the 2 parietal placentae intruded and expanded in the center of the cavity into broad surfaces bearing the ovules in 1 or 2 rows. Fruit an incurved beaked loculicidally 2-valved capsule, the exocarp somewhat fleshy, the endocarp fibrous, woody, crested below or also above, 4-celled by the extension of the placentae. Seeds numerous, tuberculate. [Named for John Martyn, 1693-1768, professor of botany at Cambridge, England.]
About 8 species, natives of America. Besides the following, 2 others occur in the southwestern United States. Type species: Martynia annua L.
Annual, densely glandular-pubescent all over; stem stout, much branched, the branches prostrate or ascending, 1°-3° long. Leaves broadly ovate to orbicular, rounded at the apex, cordate at the base, repand, undulate or entire, 3'-12' in diameter, the petiole stout, mostly longer than the blade; bractlets at the base of the calyx oblong or linear, deciduous; calyx somewhat cleft on the lower side; racemes several-flowered; pedicels slender; corolla whitish or yellowish, mottled with purple or yellow within, 1 1/2'-2' long, the limb nearly as broad, the lobes obtuse; stamens all anther-bearing; fruit strongly curved, 4'-6' long when mature, the beak longer than the body, splitting into 2 elastically diverging segments, the endocarp crested on the under side only.
In waste places, escaped from gardens, Maine to western New York, New Jersey and Georgia. Native from Indiana to Iowa, Utah, Texas and New Mexico. July-Sept.