The Cup Plant, known in Latin as Silphium perfoliatum towers nearly 12 feet tall at the back of the herbaceous border. It is so named because the large triangular leaves are perforated by the stem, forming a cup in which water collects for the benefit of insects and other forms of wildlife in the garden.
Almost as tall is the Whorled Rosinweed, Silphium trifoliatum. This plant is named for the whorl of three leaves (trifoliate) that circle the stem.
It was first described by the eminent Virginia botanist, John Clayton, Clerk of Court for Gloucester County and author of Flora Virginica printed in Leiden, Holland by Gronovius and heavily relied upon by Carlous Linnaeus in his groundbreaking work Species Panatarum published in 1753.
Curiously, Clayton described this plant as “foliis quadratim positis,” meaning “foliage four-fold placed” or whorls or four.
While it is true that the foliage is usually composed of whorls of three, there are also examples of plants that carry their leaves in whorls of four which Mr. Clayton must have encountered.
To support these giant plants from blowing down during summer storms we have devised a support made of stakes that are sharpened and driven into the ground with a lattice of grape vines laid over them and nailed in place.
The plants grow up through the vines and are thus supported in blustery weather.
Sylvie in Rappahannock says
The cup plant attracts lots of pollinators - and it so very cheerful. Yes, its downside is that lankiness, but if contained and staked - as done in Williamsburg - they can make an informal warm weather edge around the garden. I have just pruned some of my cup plants which were too unruly: I use their dry stems as a particularly effective fire starter. That’s true of other members of the sunflower family including Jerusalem artichokes.
Dearest Linda and Sylvie,
A flower border has value beyond simple ornamentation for it is only through the study of the natural world that we can understand the complexities of nature and discover our own place within it. Botany is an essential part of a gentleman’s education and what better place to study it than on one’s own estate? We may ponder the reason the cup plant has been formed to gather water for the benefit of other creatures and whether or not it derives some benefit from this association itself. Is it to be hoped the Rosinweed provides the same elixir for which the genus is named? The original Silphium, now long extinct, founded the wealth of ancient Cyrenaica in present-day Libya and an entire civilization perished with the plant. If nothing else, it surely provides a lesson in stewardship. Perhaps we would all be better served if our current leaders placed the same importance on understanding the natural world as their predecessors did. As to the support structure, we find that it will last for two years before needing to be replaced and this is most easily done during the winter months.
Yr. most humble and obedient servant,
Wesley Greene
Sylvie in Rappahannock says
Dear Wesley
I love your support system! I resolved this year that one must be installed for the cup plants, because - indeed - invariably they are blown down. Or they are so heavy with flowers that they blow themselves down! Your solution is much more elegant than what I was thinking about. I also notice it is installed very early in the year.
Linda Shoun says
What are the reasons these are in the garden? Since you are taking steps to protect them from weather, they must have value beyond that to the insects and other critters. Are they beautiful? Edible? Soil-enriching? Or?????