The daffodils and crocuses may already be popping up around town in sunny spots but most of the native plants in Nantucket’s moors, grasslands and forests are still waiting for warmer and longer days to flower.
Except for one! Hiding in the Middle Moors of Nantucket, in the low and open heathy expanses, the miniscule and diminutive flowers of the rare Broom crowberry (Corema conradii, affectionately referred to as Corema) are opening up!
Corema‘s flowers are fairly nondescript and very small. You will often only realize you are tromping through the midst of flowering Corema by the large clouds of sneeze-inducing pollen rising through the air. Corema plants are dioecious, meaning each plant either carries male flowers (with stamens of pollen) or female flowers (with pistils to capture and deliver the pollen to ovaries, ripening into seed) but not both. Male and female flowers begin opening in late March and into early April with spring winds dispersing pollen.
You have probably seen Corema in the Middle Moors and hadn’t realized you were seeing it. In the Middle Moors, it forms large monocultures, giving an almost moonscape appearance in large patches. This low growing, mounding plant grows best in open areas with sand poor soils and lots of light, spreading across a landscape to create an almost moonscape. Corema is listed as Special Concern in Massachusetts and although abundant in areas where it is present, is fairly rare in most of New England. Where Corema is present, it tends to dominate with a few other plant species able to grown under or up through this dense plant.
Corema can often be mistaken for golden-heather (Hudsonia ericoides) when neither are yet in bloom. Looking closely, Hudsonia leaves are often softer, hairier than the small leathery Corema leaves and Hudsonia‘s bright golden yellow spring flowers will set it apart. Because of its small stature and non-showy flowers, Corema has often been dismissed over the years.
See this excerpt from the 1921 book “Nantucket Wildflowers” by Alice O. Albertson, Curator of the Nantucket Maria Mitchell Association:
“This plant is included, not because it has aesthetic charm but rather because it is interesting botanically. Its presence on Nantucket, is one of the proofs that, ecologically, Nantucket and the plains and pine-barrens of New Jersey are related.”
The pine-barrens of New Jersey are dominated by fire-adapted plants as is Nantucket – plants that typically require fire or some kind of disturbance as part of their lifecycle. Without disturbance, this plant will grow for many years with some of the populations in the Middle Moors estimated at 100 years old. Corema is a woody plant and new growth is apical – growing outwards from the tips of the plant so the center appears woody, grey and lifeless. Studies of the ecology of Corema have determined that seeds germinate only when disturbance and fire is present. Without fire, plants will continue to grow but no new seedlings will grow up. Fire kills the parent plants but leads to large scale germinations of the huge seed bank in the soil underneath these old plants. Looking at historical photos, and where Corema populations are now in the Middle Moors – these plants likely established as the old main road from Town to Sconset shifted around and became deeply rutted from old wagon wheels!
Management of Corema needs to be carefully planned out to maintain both older plants and encourage new seedling growth. Today, the Conservation Fuundation manages aging Corema populations through periodic, patchy burns across the landscape – trying to keep mature Corema populations as well as establishing new seedling populations!
So if you’re feeling like shaking off the cold of this winter and seeing a native plant in flower, take a walk in the Middle Moors this weekend (particularly along Barnard Valley Rd – put it in your Maps app!) and keep an eye out for the rare Corema. Maybe bring a magnifying glass and check out this tiny but beautiful flowers on one of our rare and unique plants!
The Nantucket Conservation Foundation is a private, non-profit land trust that depends on contributions from our members to support our science projects, conservation property acquisitions, and land management efforts. If you are not already a member, please join us!