The seed pods of the Northern Catalpa tree, often called “beans,” are not edible and are considered toxic to humans and pets. This widely distributed tree, known for its distinctive appearance, produces long pods that can cause confusion for those unfamiliar with the species.
Understanding Northern Catalpa “Beans”
Botanically, the structures called “beans” on a Northern Catalpa tree are seed pods or capsules, not true legumes. These long, slender pods typically range from 8 to 20 inches in length. They emerge green in summer, resembling elongated green beans, and mature to dark brown in the fall. They persist on the tree through winter, often splitting to release numerous flat, winged seeds in spring. Their appearance leads to the common name “cigar tree.”
Toxicity and Potential Effects
The Northern Catalpa contains toxic compounds, including iridoid glycosides like catalpin and catalposide. Ingestion of any part of the tree, including the “beans,” can lead to adverse reactions in humans. Symptoms may include gastrointestinal upset such as vomiting, diarrhea, and nausea.
For pets, especially dogs, ingesting Northern Catalpa leaves, bark, flowers, or pods can cause more pronounced symptoms. These include gastrointestinal upset, vomiting, diarrhea, and lethargy. Severe reactions may involve difficulty breathing, muscle tremors, seizures, or cardiac abnormalities, potentially leading to organ failure if a large quantity is consumed. If a human or pet is suspected of ingesting Northern Catalpa plant material, seek immediate medical or veterinary attention.
Identifying the Northern Catalpa Tree
Identifying the Northern Catalpa (Catalpa speciosa) involves several distinct features. It is a medium to large tree, typically 40 to 60 feet tall with a 30-foot spread. Its bark is gray to reddish-brown, developing a flaky or scaly texture with age. Prominent are its large, heart-shaped leaves, 6 to 12 inches long, arranged opposite or in whorls of three. In late spring to early summer, it produces showy, fragrant, trumpet-shaped white flowers with yellow centers and purple spots.
Other Uses and Importance
Despite its toxic pods, the Northern Catalpa tree holds significant value. It is widely planted as an ornamental tree in landscapes and parks due to its attractive leaves, showy flowers, and unique seed pods. Its fast growth rate also makes it a popular choice for shade. The wood is notably durable and resistant to rot, suitable for fence posts, railroad ties, and furniture. The Northern Catalpa also plays an ecological role as the primary host for the catalpa sphinx moth caterpillar, a prized natural fish bait.