"Once upon a time, about ten years ago, a friend from West Virginia came to the Eastern Shore of Maryland with a gift of three tiny, scraggly native plants called Silphiums. Today they are doing well in the garden, favorites of mine, the birds, the bees and the butterflies.
All three developed deep tap roots, the ability to endure rough weather, bright sunflower-like yellow blooms, great structural form in winter and a definite desire to attract wildlife of the flying kind in all seasons.
Large, strong plants with a controversial past, one is considered invasive in New England, another made the endangered list in Michigan, all three are known for medicinal properties – the three silphiums enchant my place and will, I hope, choose to stay. Or as I like to think of them, the plants for the future of gardens, reminders of the great prairie spaces inhabited by buffalo in the Midwest, of ancient days when ferns were trees, and clubfoot pine grew to heights unimagined. Cup plant (Silphium perfoliatum) prefers regular distribution of water, yet it grows well in my yard, with our disturbing and alternate regime of drought and flood, where it multiplies (happily, it invades). I do set the hose and water it for ten minutes, when things get truly bad. Tiger swallowtails, black swallowtails, monarchs, cabbage white, skippers and a myriad of bees and wasps seek the sweet nectar food of the flowers.
Silphium perfoliatum quenches the thirst of an infinite number of insects. While photographing butterflies, I am always careful of the wasps and spiders hovering and crawling about. The common name refers to the intersection of the square stem and rounded leaves, where a virtual drinking vessel is formed.
I do not collect seeds because the plants self-seed and spread. In my garden this is desirable, and I enjoy the tall showy mass of yellows in flower, in bloom from early July until September. It is threatened in Michigan, considered invasive in Connecticut and non-native in Maryland. Prairie Dock (Silphium terebinthinaceum)
The second Silphium is Prairie Dock. Silphium terenbithinaceum, or the one that contains turpentine. It sends roots down deep and survives harsh drought conditions. Rough leaves spread out in a rosette and strong stalks reach up for the sky in multiple yellow blooms. This year it is starting to bloom only now, in August, later than in other years. I photographed the flowers for the first time this year, and have not seen butterflies there yet.
Compass Plant (Silphium laciniatum)
Then we come to the forgotten one, the endangered one – the Compass plant. Described in the literature as a guiding companion to explorers, it blooms in July and August here. Favorite perch for goldfinches in the fall, when seeds are ready and plentiful. When young it reminds me of the tropical Monsteras deliciosas of my teen years, house plants in the Northern Hemisphere, but wilderness statements in the South. The Compass Plant sends strong shoots up into the blue sky and it blooms, like sunflowers tend to bloom. The stalks are so heavy they eventually fall. I leave them on the ground and have seen early spring birds feeding on the seeds. In an article for the the Missouri Conservationist, Carol Davit explains how the basal leaves arrange themselves in a North South direction so as to maximize exposure to the morning sun and conserve energy during the heat of the day. The Compass plant is my wild companion, it dies in winter, and I wonder every year if it will come back to grace my territory. So far, for some ten years, it has. This year I will try to propagate it by seed. " Posted by Erica at 06:13, August 8, 2010, in the Prosasemilinear blog, No comments: Labels: Adaptation, Botany, Butterflies, Conservation, Flowers, Prairie *** It is now 2023 and I have seen dozens and dozens of cup plants multiply and flourish in the yard, a continuous joy for butterflies, insects and birds of all kinds. One lonely compass plant still persists in returning every year, in a spot with maybe way too much shade. It has not bloomed in two years, but I still have high hopes! My one prairie dock died in 2017, during a particularly dry year. I miss her bold color statements and find myself checking the spot in spring, to see if she might decide to return. And now I learn that a fourth silphium, Rosinweed or Silphium integrifolium , “a drought-tolerant perennial prairie plant (is) being domesticated as an edible oilseed crop because of its deep, persistent root system and large seeds and flavor similar to its close relative, sunflower (Helianthus annuus). ” Click on link for a citizen science project and field guide: https://landinstitute.org/wp-content/uploads/2022/05/Silphium-Field-Guide-2022.pdf I experimented once with rosinweed and planted it here, next to my main cup plant garden but it lasted only for one season… The report from the Land Institute also states that “The species Silphium perfoliatum (cup plant) is of special interest because it is being domesticated as a forage and bioenergy crop in Europe. We have made hybrids between S. integrifolium and S. perfoliatum and we are crossing the hybrids with each other. The hybrids may end up as a distinct type of domestic silphium” Although listed as non native in Maryland, I will continue to praise my silphiums as a great solution for this place with spots of deep compacted clay and alternating regimes of drought and flood. Beautiful plants!
Erica -- many years ago, you gave me a small clump of wild geranium. As I recall, I came home with it in a paper cup. Since then, it has grown into two sturdy groupings on either side of my front steps. It sends up its lavender blooms each spring and always reminds me of you. Though my conditions may be different from yours, I'd love to see how your cup plant performs here. It sounds perfectly wonderful.