This section is from the book "Woody Plants In Winter", by Earl L. Core, Nelle P. Ammons. Also available from Amazon: Woody Plants in Winter.
Small or medium-sized deciduous trees. Twigs thick, round; pith large, round, pale, continuous. Buds solitary, sessile, globose, with about 6 loose scales; terminal bud lacking. Leaf-scars elliptic or round, in whorls, alternately of 2 large scars and 1 small scar, then 1 large scar and 2 small scars; stipule-scars none. Pods long, terete, persistent in winter. Seeds winged all around, the wings ciliate at each end.

Fig. 290. Catalpa speciosa.

Fig. 291. Catalpa bignonioides.
a. | Capsules about 1. 5 cm. thick; hairs of the seeds not coming to a point | 1. | C. speciosa |
a. | Capsules 0. 8-1. 2 cm. thick; hairs of the seeds coming to a point | 2. | C. bignonioides |
1. C. speciosa Warder.Catawba-Tree. Cigar-Tree. Northern Catalpa. A large tree to 30 m. tall, of pyramidal habit; bark red-brown, broken into thick scales; capsule thick; seeds truncate. Damp woods, Tennessee to Texas, north to Indiana and Iowa; cultivated and naturalized elsewhere (Fig. 290 ).
2. C. bignonioides Walt. Common Catalpa. A low tree to 15 m. high, or taller, with wide-spreading branches forming a broad round head; bark light brown, separating into thin scales; pods slender; seeds pointed. Native of the southern and Gulf states, cultivated and frequently escaped northwards (Fig. 291 ).
 
Continue to: