Species of the Month
Eastern Redbud
Cercis canadensis
May is a month of riotous colour at Ruthven Park. Colourful warblers flit through the trees, a wide variety of plants display their finery through showy flowers, and a plethora of insects such as butterflies, beetles, and dragonflies display gaudy colours. Even typically staid trees join the show. One of the most colourful “native” trees in southern Ontario, sporting light to dark magenta flowers, is the Eastern Redbud (Cercis canadensis).
The Eastern Redbud is a small tree, or large deciduous shrub, native to the eastern United States. It is considered native to Canada based on the presence of a single individual on southern Pelee Island recorded by Irish Canadian botanist John Macoun in 1892. Now more widely spread in southern Ontario all individuals are thought to be descendants of plants brought in from the United States or escaped cultivars.
With a maximum height of between 10 and 12m, the Eastern Redbud is an understory tree, and prefers to grow in moist bottomlands, typically in association with American Basswood (Tilia americana), Northern Hackberry (Celtis occidentalis), and Silver Maple (Acer saccharinum). An individual Eastern Redbud will have many trunks and can encompass an area between 8 and 10m.
The bark of the Eastern Redbud is dark, or grey, in colour and can exfoliate (come off or shed) in small squarish patches to expose rusty-coloured inner bark. Twigs are dark, slender, and zigzagged. Leaves are 8 to 13cm wide, heart-shaped, and alternate.
Despite the name of “redbud” the buds of the Eastern Redbud are not red; they are more of a chestnut colour. Their flowers, however, are red – usually more magenta - in colour. The Eastern Redbud is a member of the Pea Family (Fabaceae) and has flowers similar in shape to pea plants. Flowers are approximately 1.5 cm long and can appear before the plant’s leaves have emerged. New growth tends to have single flowers while older growth can have clusters of flowers up to a total of ten or so.
The nectaries are deep, so only long-tongued insects, such as Carpenter Bees (Xylocopa spp.) – which unfortunately also seem to enjoy feasting on the buildings of Ruthven Park – can pollinate the Eastern Redbud. The resulting fruit emerges as a purplish (turning to brownish) pod containing five or more 5mm flat, brownish seeds.
The Eastern Redbud typically lives between 40 and 80 years.
The leaves of the Eastern Redbud are food to the Io Moth (Automeris io) and the American Dagger Moth (Acronicta americana). The flowers are edible and can be eaten raw, and indigenous nations are known to have eaten roasted seeds. In Appalachia green twigs were used as a seasoning for game.
At Ruthven Park look for the colourful Eastern Redbud on the formal grounds of the mansion.