2002 THE MICHIGAN BOTANIST 3

REDISCOVERY OF CORDATA () IN MICHIGAN

Bruce D. Parfitt Biology Department University of Michigan—Flint Flint, Michigan 48502-1950

Plantago cordata Lam. previously ranged from Ohio and southern Ontario to Wisconsin and Missouri, and occurred more locally in New York,Virginia, North Carolina, Georgia, and Alabama. In the 1800s, P. cordata was considered fre- quent in central and southern Michigan (Wheeler & Smith 1881). The species had been reported from Clinton, Genesee, Ionia, Macomb, and Tuscola counties (Wheeler & Smith 1881; Beal 1904) and Oakland County [as “reported by Stacy” (Bingham 1945)]. In addition, Voss (1996) mapped specimens from Eaton, Gratiot, Kent, St. Clair, Shiawasee, Washtenaw, and Wayne counties. Ex- cept for two Washtenaw County specimens collected in 1924 and 1925, all were from the 1800s, the earliest being an 1838 specimen from St. Clair County. By the twentieth century the species was rare, presumably as a result of habi- tat loss. From 1925 to 1990, P. cordata was not seen by botanists in Michigan. Today its status in the state is “Threatened” with a rank of “S1,” which indicates it is critically imperiled because of five or fewer occurrences or very few re- maining individuals (Anonymous 1992). In North America the species is now considered rare (Gleason and Cronquist 1991), or very rare and local throughout its range (G3, Anonymous 1992), though more widespread or abundant than pre- viously thought. Plantago cordata is not listed as Threatened or Endangered by the United States Fish and Wildlife Service. In 1990 Plantago cordata was rediscovered by W. H. Wagner and P. Fritsch in Hillsdale County (Voss 1996). The population consists of over 600 juvenile and 205 mature individuals occupying an area about 6 × 30 m. A second Michi- gan population of about 500 individuals was discovered by F. & R. Case in 1995 in Ionia County (Voss 1996). Both sites are documented by specimens in MICH. While engaged in a floristic study of the eastern portion of Tuscola State Game Area during spring of 1997, Debra Bassett and Elizabeth Kohan indepen- dently discovered populations of Plantago cordata in Tuscola County. The fol- lowing year, 1998, Parfitt, Elizabeth Kohan, Nan Kelly, and Charles A. Wade re- turned to study and map the populations, and to seek additional populations. Mapping of the two Tuscola County sites of Plantago cordata using a global positioning system (GPS) revealed them to be parts of one large, nearly contigu- ous population. Although the population was clearly centered on an ephemeral stream, outlying clusters of were also found in the very wet deciduous woods and in the flooded ruts of an old, now rarely used vehicle-access trail (lo- cally called a “two-track”). I speculate that such a dispersal from the stream oc- curred as a result of major flooding in June (fruiting time), 1996. Although the 4 THE MICHIGAN BOTANIST Vol. 41

Tuscola State Game Area has much similar habitat, including other ephemeral streams, searches for additional sites with P. cordata were not successful. The Tuscola County population is nearly contiguous along nearly 0.6 km (about 1/3 mile) of ephemeral stream. The large size of the Tuscola County pop- ulation precluded counting all individuals. Also, because of the inaccuracy of GPS readings, we could not obtain a precise measurement of the area occupied by P. cordata. A conservative estimate by field workers Wade, Kelly, and Kohan suggests there may be more than 4000 individuals of P. cordata in the popula- tion. The Tuscola County population is the third extant population to be discovered in Michigan, and is more than 125 kilometers from the nearest known extant population. It is also the northernmost Michigan population. The other two pop- ulations are considerably smaller. Diagnostic Characters. In spring (April and early May) young plants are so small as to resemble Plantago major L. or P. rugelii Decne. Characteristics that distinguish P. cordata from the other species are its stream or wet swamp habi- tat (instead of moist to dry places), glabrous and leaves (instead of often pubescent), fleshy roots (instead of fibrous), May flowering time (instead of June—August), and tender succulent petioles (instead of tough and stringy). By June, size alone should be sufficient for identification, with fruiting spikes of P. cordata to 6 dm tall with leaves 5 dm or more in length.

MICHIGAN. TUSCOLA CO.: Eastern portion of the Tuscola State Game Area (precise data withheld at the request of the Natural Features Inventory, Michigan State University Exten- sion); [swamp/marsh margin], emergent in standing (or slightly flowing) water, April 1997, Debra Bassett 150 & Karen Gould, (MICH, UMF); swamp, 10 May 1997, Bruce D. Parfitt 5787 & Elizabeth G. Kohan (MICH, UMF); swamp along stream north of open marsh, 29 May 1998, Bruce D. Parfitt 6018 with Nan Kelly & Charles A. Wade, (MICH, OSH, UMF).

ACKNOWLEDGMENTS Special thanks to Nan Kelly and Charles A. Wade for running transects and plots, and to Eliza- beth G. Kohan, Derrick Townsend, Debra Bassett, Karen Gould, and Star Shelton for many hours of field work leading to this discovery.

LITERATURE CITED Anonymous. 1992. Michigan’s Special Plants—Endangered, Threatened, Special Concern, and Probably Extirpated. Beal, W. J. 1904. Michigan flora—a list of the fern and seed plants growing without cultivation. State Board of Agriculture, Lansing. [Reprinted from the 5th Report of the Michigan Academy of Sci- ence.] Bingham, M. T. 1945. The flora of Oakland County, Michigan—a study in physiographic plant ecol- ogy. Cranbrook Institute of Science Bull. No. 22: 1–155. Gleason, H. A. & A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada, ed. 2. New York Botanical Garden, New York. Voss, E. G. 1996. Michigan Flora, part III (Dicots. Pyrolaceae—Compositae). Cranbrook Institute of Science Bulletin 61, and University of Michigan Herbarium, Ann Arbor. Wheeler, C. F., & E. F. Smith. 1881. Catalogue of the phaenogamous and vascular cryptogamous plants of Michigan, indigenous, naturalized, and adventive. State Horticultural Society, 10th An- nual Report. W. S. George & Co., State Printers and Binders, Lansing.