princesstree Paulowniatomentosa (Thunb.) Sieb. & Zucc. ex Steud.
Appearance
Paulownia tomentosa is a medium sized tree (50-60 ft. [15.2-18.3 m] in height and 2 ft. [0.6 m] in diameter) that can commonly be mistaken for the native tree northern catalpa (Catalpa speciosa). Bark is gray-brown and rough, often developing lighter-colored shallow vertical fissures.
Foliage
Leaves are large, broadly oval to heart-shaped (6-12 in. [15.2-30.5 cm] long, 5-9 in. [12.7-22.8 cm] wide) and arranged opposite along the stem, hairy on both surfaces. Petioles are also hairy and can be sticky when young. Leaves growing off root sprouts have been measured up to 2 ft. (0.6 m) in length. Twigs are stout, brown, and speckled with white dots (lenticels). They can be slightly hairy when young. Lateral leaf scars are somewhat round, becoming darker and sunken. The pith is chambered or sometimes hollow.
Flowers
Large flowers (2 in. [5.1 cm] long) are fragrant and light violet-pink, appearing in showy upright clusters (8-12 in. [20.3-30.5 cm] in length) in early spring (April-May) before leaves emerge. They have tubular corollas, ending in 5 unequal lobes. Flower buds are hairy and linear, becoming round.
Fruit
Fruits (1-2 in. [2.5-5.1 cm] long, 1-1.5 in. [2.5-3.8 cm] wide) are egg-shaped capsules, divided into 4 inner compartments that contain the seeds. Fruits are light green in the summer, becoming dark brown in the winter, and persist in clusters on the tree until the following spring. The capsules split in half during late winter to release up to 2000 tiny winged, wind-borne seeds 0.08-0.12 in. (2-3 mm).
Ecological Threat
Paulownia tomentosa is an aggressive tree that invades disturbed natural areas including forests, roadsides, and stream banks. It is native to China and was first introduced into the United States as an ornamental in 1840.