“I swear by Apollo the physician, and by Asclepius and by Hygieia and Panacea….”. So begins an old version of the Hippocratic Oath taken by physicians in the past. Many have seen the Rod of Asclepius, a rod entwined with a single snake, as the symbol of medicine to this day. This is often confused with the caduceus, a staff entwined with two snakes and topped by two wings. The caduceus has been adopted by many medical institutions, including the US Army Medical Corp, some say by a mistake of history with the caduceus more appropriately associated with commerce. The Rod of Asclepius takes its name from the Greek god Asclepius, son of Apollo in Greek mythology, and a deity associated with healing. His daughters Hygieia and Panacea represent cleanliness and universal remedy.
Asclepias, the genus of milkweeds and named after Asclepius, is found in many open fields, including the remnant prairies in Hixon Forest and the surrounding bluffs. The Asclepias genus is represented by several species. On Zoerb and Lookout prairies there are at least 4 species- common milkweed (Asclepius syriaca), butterfly weed ( A. tuberosa), whorled milkweed (A. verticillata), and green milkweed (A. viridiflora). The milkweeds produce a milky sap that was once thought to be useful for various medical conditions, hence the name. Conversely, the plant is known to produce toxins called cardenolides and is the obligate host of the monarch butterfly caterpillar, which is immune to these toxins. Monarch caterpillars consume the leaves of milkweed, accumulate the toxins, and become distasteful to would be predators. The monarch population has declined significantly in the last couple of decades and loss of milkweeds, which were more numerous in the past, may be a contributing factor. Several other butterflies besides monarchs also feed on the abundant nectar produced by the milkweeds, including the great spangled fritillary seen here on common milkweed.
Milkweed is also an important food source of nectar and pollen for many native bees, including bumblebees, moths, and beetles. It has a complex flower structure arranged in an umbel that have pollen sacs hidden in small slits. When an insect visits the flower, its leg often ends up in one of the slits thereby carrying the pollen to the next plant. Some insects, however, are too small to pull their leg out of the slit and become trapped. It either loses its limb to escape or dies in the trap. Only a small percentage of the flowers are pollinated and become seed pods that contain about 200 seeds that are subsequently carried off in the wind due to the fluffy hairs on each seed.
Reversed Haploa Moth on Butterfly Milkweed
As Friends of the Blufflands continues in its efforts to restore the remnant prairies and to manage newly formed prairies, know that many insects, as well as a host of other species, are benefitting from the milkweeds and, more importantly, from the whole community of prairie plants that bloom and produce much needed food, nectar, and pollen. Please consider supporting these efforts by donating to our group and joining as a volunteer on work days.