May 08, 2020 • Madison Square Park Conservancy

Madison Square Park’s redbud trees put on a show every spring! Commonly known as Eastern Redbud, this small to medium-sized tree is native to North America and Asia.

A beautiful burst of pink Cercis canadensis flowers.

As a member of the family Fabaceae, the redbud is related to several other plants that grace the Park with their presence, including cassias, wisteria, and black locust. Plants of this family are related to the peas and beans, and the relationship is noticeable in their flowers. The flowers of the redbud, as well as other members of Fabacea, are very similar to those of a pea flower, often having an upper petal that looks like two fused together (a banner) and two lower petals actually fused together (the keel) that enclose the flower’s reproductive parts.

Redbud flowers borne along its bark.

For redbuds, in particular, close inspection will reveal the presence of a keel, but no banner. The keel protects the reproductive parts from rain until a pollinator visits the flower. Here at the Park, these pollinators are often honeybees, bumblebees, or native leaf-cutting bees, which also cut out distinctive (but only cosmetically damaging) holes in redbud leaves. Redbuds flower early in the season, with flowers borne along the branches of the tree rather than only at the apex of stems. The odd location of the flowers makes for a gorgeous site when these trees bloom in early spring. The flowers are present before the leaves develop, allowing for a floral display with little distraction. Following flowering, redbuds develop long, dry seedpods called a legume that resemble a bean pod, another clue to their shared heritage.

Cercis canadensis at the 26th and Madison entrance

Thanks to our horticulturalists at Madison Square Park, we keep phenological data on our redbuds. Cercis sp. They are one of our five collection plants in the Park, with over 30 distinct cultivars present and more anticipated. While most are eastern redbud, a native to the eastern reaches of North America, there are several cultivars of Cercis chinensis, Chinese redbud, as well as a small number of other species.

Facts

• Redbuds exhibit the phenomenon of cauliflory, where flowers are borne directly on their trunks and stems, rather than on newly produced shoots
• The generic name, Cercis, is greek for “Weaver’s shuttle”, a reference to the resemblance of the seed pods to a weaving shuttle
• Several species of Lepidopteran larvae feed on redbuds, including the cosmopolitan mouse moth, Amphipyra tragopoginis
• Redbud bark, specifically C. chinensis, is used as an antiseptic agent in Chinese medicine
• The flowers are edible and noted for having a refreshing, acidic taste that goes well in salads

Posted on May 8, 2020 03:23 PM by mspceco