In the Wild ...

Milkweed

By Mary T. Harrington


The first day of the Autumnal Equinox was September 22, 2001. There is now an even amount of daylight and darkness. The air is beginning to cool; the green in the leaves is beginning to change. In some cases the leaves are already moving to colors of yellow or red. There is not enough daylight at this time to sustain the chlorophyll in the leaves. The chlorophyll is beginning to die and as it dies the green of the leaves goes with it. What are left on the leaves after the chlorophyll is gone are the amazing and beautiful colors of fall.

The Butterfly and Hummingbird garden is in its autumnal peak, as well. Tinthonia or Mexican Sunflower and Pineapple Sage are in full bloom attracting not only a variety of butterflies but hummingbirds as well. The Monarch butterflies are well into their migration to Central and South America. They have been laying eggs with larvae hatching throughout the summer. Planted in the garden is a variety of milkweed species preferred by the Monarch ranging from common milkweed (perennial) to a tropical variety (annual). This is a key plant of the garden at Lenoir.

Milkweed (Aesclepias Sp.) is a plant that grows between 2-6 feet. It has a thick stem with opposite paired leaves that are oblong about 4-6 inches in length, rounded toward the stem and pointed at the tip. The flowers range in color from yellow/orange, green to a beautifully fragrant pink/lavender. The flowers are slippery so that whenever a pollinating insect step on it, it will slide off the petal and right into the center of the flower where it will get covered with pollen. This mechanism assures cross-pollination for the species. The seedpods are quite noticeable right now. Many have already burst open to reveal the hundreds of seeds with silken parachutes.

Milkweed has sophisticated method of defense from which its common name is derived. There is milky sap or juice in the stems of this plant. Ants can puncture the stem as they walk making the milkweed plant vulnerable to disease or attack. The milky white juice then seeps out and captures the ant's feet therefore deterring them from further damaging the plant. Monarch larvae, however, seek this juice as a protection against predators since it is bitter tasting and emetic (producing vomiting). It has proven to be a very effective defense for the butterfly larvae who just tastes bad. This sap was also researched as an alternate source of rubber in WWII. The process was impractical and expensive given the yield and it was eventually abandoned.

This plant has historically been used for a variety of medicinal purposes. In fact, its generic name comes from the Greek god of medicine, the Latin translation of his name being Aesculapius. The roots were used as a contraceptive and to treat dysentery. The sap was utilized to treat venom bites and to remove warts. The leaves were dried and mixed with tobacco to be smoked in pipe for the treatment of asthma. This plant is not used medicinally today.

Young milkweed shoots have been considered a wild asparagus. It is carefully prepared meaning any sap is removed prior to cooking. The stems are extremely fibrous and have been used as source for cord or string.

This is a beautiful and valuable plant. Don't forget to come to the Butterfly and Hummingbird garden to see it.

Mary T. Harrington

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