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..
A large tree, with the aspect of Catalpa, with broad opposite entire or 3-lobed, petioled pubescent leaves, and large violet flowers in terminal panicles. Calyx deeply 5-cleft, the lobes short. Corolla irregular, the tube elongated, enlarged above, the 5 lobes spreading, somewhat unequal. Stamens 4, didynamous, included; anther-sacs divaricate. Style slender, slightly thickened toward the summit, stigmatic on the inner side. Capsule coriaceous, ovoid, acute, loculicidally dehiscent. Seeds numerous, striate, winged. Flowers expanding before the leaves appear. [Named for Anna Paulowna, daughter of the Czar Paul I.]
A monotypic Japanese genus.
Bignonia tomentosa Thunb. Fl. Jap. 252. 1784. Pauiownia imperialis Sieb. & Zucc. Fl. Jap. 1: 27. 1835. Pauiownia tomentosa Baill. Hist. Pl. 9: 434. 1888.
A tree with thin flaky bark, reaching a maximum height of about 700 and a trunk diameter of 4°, the branches stout, spreading. Leaves broadly ovate, 6'-15' long, 4'-8' wide, long-petioled, canescent on both sides when young, glabrate above when old, the petioles terete; flowers about 2 1/2' long, numerous in large erect terminal panicles; pedicels stout, densely tomentose; calyx 5-lobed, the lobes thick, tomentose; corolla slightly irregular, puberulent without; capsule 2' high, 1' in diameter.
Escaped from cultivation, southern New York and New Jersey to Georgia. May-July.