2016-06-25 / Columnists

Nature Notes

Yellow Flowers Mark Summer’s Arrival
By Patricia Martin

I always think of summer as the time of yellow flowers. Many of the plants that seem to bloom this time of year, and especially in abundance, seem to be yellow-flowered. Think of the dandelion. Right now, three yellow-flowered plants are blooming in abundance on Mackinac Island, none of which are native. The first is the golden lungwort, spotted hawkweed, or one of the European hawkweeds (Hieracium murorum, H. maculatum, H. lachenalli) that now have spread through much of our woods, especially under the northern white cedars, although now also found in our mixed and hardwood stands. By the way, it is a relative of the dandelion.

The second yellow-flowering plant that seems to be blooming in great numbers is the tall buttercup (Ranunclus acris). This native of Europe has been found in Michigan since the 1830s, and by the 1860s it was found from southern Michigan to Isle Royale. It has spread everywhere with its bright yellow flower. Some authors indicate that it likes wet places, but it seems to do fine in almost any disturbed area or open space. Right now, it’s growing along the fence of the paddock where I turn out my horse. The horse seems to eat everything around, but not the buttercups. Most people are familiar with the glossy, five to seven petals that overlap on this herbaceous plant, which stands two to three feet tall. We, as children, used to hold them up under someone’s chin, and, if the underside of the chin looked yellow, it meant they liked butter (as long as the sun was shining, the yellow of the buttercup reflected on a person’s skin, so pretty much everyone liked butter).


Celandine (Chelidonium majus) (Photograph by Candi Dunnigan) Celandine (Chelidonium majus) (Photograph by Candi Dunnigan) The third yellow-flowering plant that is blooming right now is the celandine (Chelidonium majus), a Eurasian import that is sometimes a locally common weed of roadsides, dumps, railroads, woods, thickets, and gardens, as it is widely introduced to North America. Over the last 20 years or so, this non-native has spread to many areas. It is in the poppy family. It has been called greater celandine, or tetterwort, nipplewort, or swallowwort. Sometimes, it has locally been called celadon, which is a plant also found in the poppy family.

This plant is a perennial herb with an erect habit and reaches 15 to 60 inches in height. The leaves are pinnately lobed and have wavy, edged margins and are quite large. If the plant is cut or broken, it exudes a yellow to orange latex sap. The flowers consist of four yellow petals, each about one-half inch long with two sepals. The flowers, found in groups of four, appear from late spring throughout summer. The seeds are small and black and are borne in a long cylindrical capsule. Each seed has an elaiosome that ants like to eat. The ants collect the seeds with the elaiosome and take them back to their nest. The elaiosome is eaten and the seeds are considered waste by the ants, and they throw them out of their nests along with other waste, which provides nutrients for the seeds to grow. This process is known as myrmecochory. It is considered an aggressive, invasive plant in natural areas, and control is obtained mainly by pulling the spring plant before seed dispersal. It grows well in poor soil, and is therefore found in disturbed areas.

The plant is the only member of its genus. The genus name Chelidonium is from the Greek word for swallow (chelidon). Some legends connect this plant with the swallow, saying that the birds used the juice of the stem to strengthen the eyesight of the nestlings. That explains one of its common names (swallowwort). Another story is that the flower of the celandine doesn’t bloom until the swallows return in the spring, and it will continue to bloom until the swallows leave. It is also one of the plants described by the father of taxonomy, Carl Linnaeus, in Volume One of his “Species Plantarum,” in 1753.

The sap of this plant has been used by herbalists as a medicinal for centuries. Pliny the Elder and Dioscorides (first century AD) recognized this herb as a detoxifying agent. It has had a variety of uses. The yellow sap has been used to treat jaundice and liver ailments, gallstones and dyspepsia, and to remove warts, corns, and freckles. The latex of the plant has been employed for cauterizing wounds. It was also used to treat ringworm, eczema, and “the itch.” It has also been thought to be an effective eye medicine when diluted with milk. Falconers who had sick birds were said to have used bits of the root for treatment.

The problem with any of these treatments is that the whole plant is toxic in moderate doses as it contains a range of isoquinoline alkaloids, which can be therapeutic in correct dosages, but in the wrong amounts can be toxic. The fresh herb is a mild analgesic, and the root has been known to be chewed to relieve toothache, and has been shown to be somewhat antimicrobial, and even a central nervous system sedative. Some alkaloids have shown potential against methicillin-resistant staphylococcus aureus, so this “weed” may some day be quite a useful plant.

In addition, one old charm said that if you carried celandine with the heart of a mole, you would “vanquish your enemies and win your lawsuits.” So, next time you’re in court, you might want to carry some with you.

Trish Martin is a yeararound resident of Mackinac Island, has earned a master’s degree in botany from Central Michigan University, and owns Bogan Lane Inn.

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