Perhaps my professional interest in horticulture is to blame, but there are several plants that trigger fond memories of my youth. Celandine Poppy, Stylophorum diphyllum used to line the shady edge of the lawn adjacent to my parents’ house. I found it very entertaining to break the stems and see the orange latex sap flow forth. The sap originally evolved to prevent predation, but I found it to be a fine alternative to ink! Little did I know, the rather caustic liquid can create welts if it comes in contact with the skin, can seriously burn the eyes and was used by the Native American Indians as a dye and as war paint.
Stylophorum diphyllum (see Photo 1) is a member of the Papaveraceae or Poppy Family and is native to Eastern North America. A rather small genus, it only contains two additional species native to China. The plant was originally named Chelidonium diphyllum in 1803 by the French botanist André Michaux (1746-1802). The name was published posthumously in his book Flora Boreali-Americana (The Flora of North America). Chelidonium is a very closely aligned genus in Europe, with smaller flowers and stature. It is also biennial in nature verses being a true perennial. In 1818, the English botanist Thomas Nuttall (1786-1859) noticed the numerous differences and published the plant under a new genus in his book Genera of North American Plants. The name comes from the Greek Stylos, meaning style and Phoros for ‘bearing’, referencing the very dominant style at the center of the blossoms (see Photo 2). A style is the stalk that connects the stigma where the pollen alights, to the ovary. The species epithet means two leaves, describing how the foliage appears in pairs. Each green leaf grows to 6” long and 2 ½” wide and is divided into 5-7 lobes, giving the plant a decided fern-like appearance (as seen in Photo 1).
In late April, the initial flowers of Celandine Poppy appear as the foliage is just beginning to emerge from the rhizomatous root system. Flowering continues into early June as the plant expands to its full height and width of 18”. During summers with ample rainfall, intermittent flowering will continue through September. The flower buds emerge from between the two leaves at the tip of the stems in umbels of 2-4 buds, although they can also appear singularly. Each oblong bud is covered with protective hairs and opens to 4 golden yellow petals. Each flower measures 1-2” in diameter with a central boss of anthers, through which the long style with its rather bulbous stigma protrudes. As the flowers fade, they are replaced by an oval, four-chambered seedpod or capsule that hangs below the foliage and once again sports short protective hairs. Come mid-summer, the capsules spilt open to release the seeds which in turn are moved about by ants! Each seed has a white, carbohydrate and lipid rich elaiosome attached to the surface of the seed coat. The function of the elaiosome is to actually attract the ants, who will take the seed with the attached elaiosome back to their colony as food for their young. Once the elaiosome is eaten, the seed is deposited in a trash chamber or outside the colony to prevent bacteria or fungus from plaguing their home, where the seed is free to germinate. This interaction with ants explains how I saw a Celandine Poppy growing out of an opening in a Black Locust tree located 8’ above the ground (see Photo 3). Typically, ants with colonies in trees drop the seeds to the ground, but I suspect one ant missed his mark! Unlike the toxic nature of the orange sap, the seeds are eatable and serve as a food source for a number of wildlife, ranging from snails and slugs to mice, chipmunks and even deer.
Celandine Poppies are hardy from zones 4-9 and thrive in moist forest conditions, where the plant is protected from the midday sun. Although the plants will spread around with ease through the activity of the ants, plant populations can quickly be compromised if the shade trees are thinned or removed. Plants relish humus rich soils that are resistant to summer droughts and will naturalize rapidly (as in Photo 4). During prolonged periods without rainfall, the foliage will become tattered and the plants may go dormant, although new foliage often reappears with autumn rains. It should also be noted that the invasive Garlic mustard (Alliaria petiolate) has been known to outcompete the seedlings.
Stylophorum is not a plant that is typically found in Garden Centers, since its retail appearance becomes quickly compromised if it does not receive constant shade or moisture. Still, it is a much welcome plant for the spring woodland garden and I always relish the early golden blooms. As I look at the plants every spring, I often wonder how many other people are reconnected to their youth through the orange sap. It was a small thing, but it definitely helped to connect me with the world of plants.
Director, Rutgers Gardens