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..
Woody vines, with opposite 2-foliolate leaves, the terminal leaflet reduced to a tendril, and large flowers in axillary cymes. Calyx campanulate, the limb merely undulate, truncate or slightly 5-toothed. Tube of the corolla much expanded above the calyx, the limb somewhat 2-lipped, 5-lobed, the lobes rounded. Anther-bearing stamens 4, didynamous, included, inserted near the base of the corolla; anther-sacs glabrous, divergent. Capsule linear, flattened parallel with the thin partition, septifragally dehiscent, the margins of the valves more or less thickened. Seeds in 2 unequal rows on both margins of the partition, winged, much broader than high, the wing entire, or erose at the end. [Greek, unequal-ranked.] An apparently monotypic genus. Type species: Bignonia capreolata L.
190. 1863. Anisostichus capreolata Bureau, Mon. Bigon. Atlas 8, pt. 6. 1864.
A glabrous woody vine, often climbing to the height of 40°- 60°, the stems sometimes 4' in diameter, exhibiting a conspicuous cross in the transverse section. Leaves petioled, commonly with small, simple, stipule-like ones in their axils, 2-foliolate, terminated by a branched tendril; leaflets stalked, oblong or ovate, entire, acute or acuminate at the apex, cordate at the base, pinnately veined, 3' - 7' long; cymes numerous, short-peduncled, 2-5-flowered; pedicels 1'-2' long; calyx membranous; corolla 2' long, orange and puberulent without, yellow within; capsule $'-7' long, 8"-10" broad, very flat, each valve longitudinally 1-nerved; seeds broadly winged laterally, narrowly winged above and below, 1 1/2' broad.
In moist woods, Virginia to Florida, Louisiana, Ohio and southern Illinois. Quarter vine. April- June.