Two Incidents Lead To Identifying Rattlesnake Fern and Snake Nature Notes By

Patricia Martin

Recently two seemingly unrelated incidents occurred that caused me to write this column. The first happened when a friend described to me and showed me a picture of a plant he wanted me to identify. It was a bit difficult to tell what it was from the picture (no leaves were visible and I was looking at the screen on the back of a digital camera), but I gave him a possible identification and asked him to check the plant’s leaves to confirm the plant’s name. However, thinking about it and spending some time in the woods, I’ve come to the conclusion that my original thought was incorrect and that what he had really shown me was a Rattlesnake Fern (Botrychium virginianum).

Rattlesnake Fern

Ferns are some of the oldest species of plants living. These were some of the dominate life forms during the Carboniferous Period (345 to 280 million years ago) and their remains have become today’s coal. Ferns are vascular plants, which means they have special conductive tissue for transporting water, minerals, and nutrients throughout the plant. These plants produce no fruits or seeds, instead they have spores and a rather complicated life cycle, which generally requires them to live in moist areas. On Mackinac, I’ve found 13 species of ferns living natively.

The Rattlesnake Fern is usually about a foot or so in height, though it may be up to 18 inches tall. The frond (leaf) is a triangular shape twice dissected, giving it a lacy look. The fertile stalk, which arises from the base of the frond blade, bears the spores.

The Ojibwa used a poultice made of this fern to treat poisonous snake bites. They would collect the fresh root, mash it, and then apply it to the bite. A decoction of the root sprinkled around a wigwam supposedly would keep rattlesnakes from returning. I had always thought that the shape of the fertile frond, which looks a bit like the rattle on the tail of a snake, had given rise to the name of this fern. It is equally likely that its name came from the uses the native peoples had for this plant. It is these uses that lead me to the next topic of the column.

The second incident was related to me by a friend. She told me that a couple of friends had stopped by and told her of a snake that they had seen swimming in the lake. It was fairly long and stout. It was gray with dark patterns on its back. They wondered if it was a Massasauga. They were referring to the Eastern Massasauga Rattlesnake ( Sistrurus catenatus catenatus ), which is the only rattlesnake native to Michigan. They’re found in the Lower Peninsula and on Bois Blanc Island, just to the south of Mackinac. There are no records of this or any other venomous snake in the Upper Peninsula. The Massasauga is a medium-sized (two to three feet long) snake with a heavy body, narrow neck, and elliptical pupil in the eye. They have a deep facial pit on each side of the head between the eye and the nostril. They’re usually gray or grayish brown with dark blotches and spots on the back and sides; the belly is blackish. They have true segmented rattles on their tail, though the young may have only a button. The coloring of the young ones resembles the adults.

Finding one near water would not be unusual, as they usually inhabit marshes and swamps, though they often wander into upland meadows and woods in the summer and spend the winters hibernating in crayfish or rodent holes. These rattlesnakes are usually quite shy and tend to retreat from disturbances. They will strike if threatened.

There are other possibilities as far as the snake’s identity goes. One is the Eastern Milk Snake ( Lampropeltis triangulum triangulum ). Milk Snakes are part of the King Snake family and are a slender snake (24 to 52 inches long) with brown or reddish brown black-bordered blotches running down the light gray or tan back. There is often a “V” or “Y” on the top of the head/neck. The belly is white with a black checkerboard pattern. The young resemble the adults, with brighter red blotches and usually whiter background. The problem with this identification is that Milk Snakes are not as commonly found near water. They often live in woodlands, fields, marshes, and farmlands. And no, they don’t drink the milk from cows, a myth that gave them their name. I commonly find Milk Snakes near the woods along the East Bluff and even my backyard.

A third possibility, and I think the most likely, is that this snake could be a Northern Water Snake ( Nerodia sipedon sipedon ). This medium to large snake (24 to 55 inches long) is usually dark colored and is almost always found in or near the water. Most have dark brown or blackish blotches or bands on a lighter brown background, but many older specimens appear black. The underside has red, orange, or black spots, usually half-moon shaped, on both sides of the belly. Younger snakes are more distinctly patterned than adults with dark bands on a light gray background. These snakes live near lakes, ponds, and streams because that is where their food is, as they eat frogs, fish, and even dead fish. They’re quite aggressive and nervous snakes and will bite, though they’re not poisonous. They’re sometimes mistaken for a Water Moccasin, which don’t live this far north. Because of the resemblance, these harmless snakes have often been persecuted.

Whatever the identity of this snake, the best thing to do when you encounter one is to leave it alone to go in peace.

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