South Carolina’s native cowcumber magnolia (M. macrophylla) bears the largest leaves and flowers of all North American trees. After days of heavy rain, I looked out the window this morning into a gray fog and noticed a brilliant white bloom on the cowcumber I planted in the woodland garden almost exactly 5 years ago.
Purchased as a seedling at a spring sale of the Upstate Chapter of the SC Native Plant Society, the small tree now stands about 5-feet tall. A few hours into the day, when the flower began to open, I took photos to record the momentous occasion.
The leaves of this deciduous magnolia can reach 32-inches long and its blooms up to 20-inches across, but the largest leaf on this immature tree measures 24-inches and the flower’s tepals are 6-inches long, which would make a 12-inch spread when fully open.
The underside of leaves have a sheen that is silver to white and the tepals are marked with purple at their base, which is another unique feature.
Found in scattered populations throughout the Southeast, M. macrophylla is very rare in South Carolina, with only two small viable populations remaining in York County (primarily due to a preference for neutral soils). Thus, the tree is listed as critically imperiled in this state.
Luckily, however, it is fairly easy to grow in cultivation and is popular with native-plant aficionados and in-the-know gardeners for its spectacular leaves and flowers.