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Lygodium palmatum (Bernh.) Swartz—climbing fern, Hartford fern

Previous Knowledge. Lygodium palmatum is perhaps best known as the sub- ject of Henry David Thoreau’s affection and titling as “our most beautiful fern”. He secreted a colony’s location in Concord, Massachusetts, from all but a few close friends. It was 120 years later that the legendary colony was found by botanists (Angelo 1985). Considered local and rare throughout its core eastern range from New England to Mississippi, Lygodium is reported locally abundant only in parts of Kentucky and Tennessee where, like the collection reported here, it grows in moist, acidic soils (Flora of North America 1993).

FIGURE 1. Habitat of Lygodium palmatum Van Buren County, Michigan. Copyright James G. Krause

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FIGURE 2. Detail of Sterile Pinnae on Lygodium palmatum. Copyright James G. Krause

Previous to this collection, Michigan’s only known station of Lygodium was in the Gourdneck State Game Area in Portage, Michigan. Located and collected by Richard W. Pippen and Western Michigan University students in 1965, it rep- resented, in addition to the only Michigan occurrence, the northern-most station of the species in the United States by 250 miles (Pippen 1966). This colony is documented to have persisted as of 1999 (McKenna 2004) but recent accounts state it has become increasingly difficult to locate and may be extirpated from this location (Mike Penskar MNFI and Todd Barkman WMU, pers. comm. Sept. 13, 2012 and Oct. 23, 2012, respectively). In Michigan the plant is listed as En- dangered with a rarity ranking of S1 (critically imperiled). Significance. In addition to representing the second known station of Ly- godium in Michigan, this collection now documents, at 19 kilometers northwest of the Portage station, the most northerly station in the United States. As already noted it may also be the only station in Michigan currently. The colony reported here is vigorous and larger, at 34 m2, than the colony size of 4 m2 noted by Pippin. Growing as a dominant species of this relatively large area, on undeveloped private land, suggests this colony is not introduced. This new discovery, growing in sandy soil near a sphagnum-floored shrub swamp of Toxicodendron vernix, Osmunda cinnamomea, and Osmunda regalis, shares many habitat features known to the Portage Lygodium station (Fig. 1). It is tan- talizing to think that these habitat echoes could lead to more Lygodium discov- eries in Michigan.

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FIGURE 3. Detail of Fertile Pinnae on Lygodium palmatum. Copyright James G. Krause

Diagnostic Characters. Lygodium is a distinct and easily recognized plant; clearly a fern but unlike any other native fern in appearance and habit. It has ster- ile evergreen pinnae, ovate, deeply and palmately lobed, that fork on 1–2 cm stalks resembling two human hands about to clap (Fig. 2). The fertile pinnae are smaller than sterile pinnae, borne at the tips of the “vines” from late summer to late fall, irregularly forked or lobed and notably smaller and more finely palmate than sterile pinnae (Fig. 3) (Flora of North America 1993)(Cobb, et. al. 2005). Arguably most unique is it’s twining and climbing, vine-like habit (Fig. 4). The collection reported here represents a colony of >1000 sprouts that primarily twine around each other forming mats over stunted Sassafras albidum. The col- lected specimen was one of only two climbing plants noted at the time of col- lection. Specimen Citation. Van Buren County, Almena Township. Low, moist, open transition zone between shrub swamp and dry upland forest; Thetford loamy sand, pH: 3.9. Twining 55.9 cm vertically on Acer rubrum sapling. Sprouting profusely to form 34 m? colony. Dominant understory species; minority under- story associates: Sassafras albidum, Gaultheria procumbens, and Diphasiastrum digitatum. Overstory Acer rubrum. Surficial rhizomes dark brown with red bris- tles. Rare. September 30, 2012. James G. Krause 1 with Grant D. Krause. Col- lected Under Michigan DNR Permit #2015. (MICH).

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FIGURE 4. Twining and climb- ing habit of Lygodium palmatum. Copyright James G. Krause

Special thanks to Mike Penskar MNFI and Anton A. Reznicek MICH for their help and guidance with regard to this rare find, and to Todd Barkman for his comments on this manuscript.


Angelo, R. (1985) Thoreau’s Climbing Fern Rediscovered. Arnoldia 45: 24–26. Cobb, B., Farnsworth, E., and Lowe, C. (2005) A Field Guide to Ferns and their Related Families, Northeastern and Central North America. Second Edition. Houghton Mifflin Company. New York, NY. 417pp. Flora of North America Editorial Committee. (1993) Flora of North America, North of Mexico. Vol- ume 2: Pteridophytes and Gymnosperms. Oxford University Press, New York. 475pp. McKenna, D. D. (2004) Flora and Vegetation of Kalamazoo County, Michigan. Michigan Botanist 43: 137–359. Pippen, R.W. (1966) Lygodium palmatum, the climbing fern, in SW Michigan. Michigan Botanist 5: 64–65

——James G. Krause Paw Paw, Michigan

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Mikania scandens (L.) Willd. Asteraceae Climbing Hempweed

Previous knowledge. Mikania scandens is a vine found in wetlands of the eastern United States (USDA). It ranges from Florida to Maine and west to Texas and is considered a noxious weed in Hawaii. It was first reported from Michigan by C.D. McLouth (1896). The plant was brought to McLouth’s atten- tion in 1894, and that September, he observed it growing in the wetlands near the mouth of the Muskegon River in what is now Muskegon State Game Area (MSGA), Muskegon County. Inquiries to locals in the area allowed McLouth to conclude that M. scandens had been present since at least the mid-nineteenth century. This has remained the only report of M. scandens in Michigan up to the present (Reznicek et al. 2011). The nearest known populations are about 200 kilometers to the south in northern Indiana (Swink & Wilhelm 1994). Attempts to relocate this species in the areas described by McLouth have been unsuccess- ful, leading to this species being designated as extirpated from Michigan (Reznicek et al. 2011). Significance of the Report. This is a significant find as this is the first report of this species in Michigan since it was originally reported by McLouth in 1896. I observed three populations, all roughly within 2 kilometers of each other. Only one of the populations was surveyed and there appeared to be about 50 healthy individuals setting seed at the coordinates provided on the collection label. The other populations were in remote areas and occurred in dense Cephalanthus oc- cidentalis thickets and only a few individuals were observed at each location. More thorough surveys are needed in the areas between Cedar Creek and the Muskegon River to accurately describe the condition of the metapopulation. Diagnostic characters. Mikania scandens is a climbing herb of floodplains, often twining up Cephalanthus occidentalis to heights of 3.0 m and occasionally forming mats over Phalaris arundinacea and Leersia oryzoides. The leaves are oppositely arranged at swollen nodes, deeply cordate, palmatly veined, and toothed. The flowers are small, pale-purple to white, and form loose corymbs born on axillary peduncles (MNFI 2007). Collected specimens were observed to be blooming throughout September. M. scandens may be mistaken for Ageratina altissima as the flowers are somewhat similar. However, M. scandens is a vine whereas A. altissima is a stout upright herb. Specimen Citation. Mikania scandens (L.) Willd. Muskegon Co., Michigan: Muskegon State Game Area. 5 Miles SSW of Twin Lake. Lat. & Long.: 43° 17? 34.2 N, 86° 07??41.1??W. Between Cedar Creek and the Muskegon River along the margins of openings in the Acer saccharinum dominated floodplain forest.

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Primarily climbing on Cephalanthus occidentalis and Fraxinus pennsylvanica. There seems to be a strong association of M. scandens and C. occidentalis. Also found occasionally forming mats atop Phalaris arundinacea. Highly localized but somewhat abundant. The majority of individuals observed were fruiting and scenesent at the time of collection, 3 October 2012. Jesse M. Lincoln; (MICH).


I would like to thank Dr. Tony Reznicek for his assistance editing this paper and for confirming the identity of Mikania scandens in the field.


McClouth, C.D. (1896). Mikania scandens Willd. Asa Gray Bulletin 4: 68 Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available on- line at [Accessed Nov 2, 2012] Reznicek, A.A., E.G. Voss, & B.S. Walters. (2011). University of Michigan. Web. Available at (Accessed 23 October 2012). Swink, F. & G. Wilhelm. 1994. Plants of the Chicago region, 4th ed. Indiana Academy of Science for Morton Arboretum, Indianapolis, Indiana. xiv + 921 pp. ——Jesse M. Lincoln 1510 Colorado SE, Grand Rapids, MI 49507