Scientific Name
Catalpa ovata
The Chinese catalpa tree at first glance does not look much different from the western catalpa that is more common in our region, due to the similar leaf shape. The large leaves may more often have a lobe, tooth, or three compared to our native tree, and the flowers have more of a yellow tinge. It is also a somewhat smaller tree, usually growing no more than 30 feet tall in our region. The top two Colorado champions are 50 and 40 feet tall, but the third-place tree is just 31 feet. However, the most obvious difference is that the long, hanging pod fruits (“string beans”) of the Chinese species are far thinner, about half the width of the western catalpa’s pods. The tree also shares very similar cultural traits in terms of tolerance of heat, cold, and poor soils. There seemed to be more interest in planting this species around the beginning of this century, perhaps for canopy diversification, but interest has declined since then. An unusual hybrid between the Chinese species and a different American one has appeared several times and has been introduced to commerce. It is called Catalpa × erubescens and produces foliage that is nearly black purple initially, with the color gradually turning dark green.
This is also a good place to mention that there are frequent parallels between the floras of China and North America, with the similarity of the two catalpa species being just one example. One of the major influences on the current distribution of plants was the Pleistocene glaciation, which forced many species to migrate southward, where they persisted in warmer refuges until they could migrate north again. This occurred in both China and North America, but Europe fared much worse because mountain ranges such as the Alps and Pyrenees prevented plants from moving far enough south to escape the glaciers.