Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.
Although a few of Wave Hill’s hardy water lilies are in bloom this week, many of the plants in the Aquatic Garden are biding their time for their big moment a little later in the summer.
One exception is pickerel weed (Pontaderia cordata). With spikes of tightly-clustered, lavender-blue flowers that stand tall above arrowhead-shaped foliage, it is a dramatic sight and one that will continue for several weeks yet.
Native to the wetlands of much of eastern North America, it is categorized as an emergent aquatic plant, for the simple reason that its stems emerge above the water line. Such plants are usually found in shallow water, such as at the edges of ponds and rivers, where the roots can take hold in the mud below.
Other aquatic plants, such as the water lilies, are able to root in deeper water. They have long, flexible leafstalks (petioles), attached to leaves that float on the water surface. Unsurprisingly, these are called floating-leaf aquatics.