Carex of Hosah Park, Zion, Illinois

Carex of Hosah Park, Zion, Illinois

By Linda Curtis,    July 23, 2013

Contact: Marilyn Krieger


Hosah Park is a rectangular 22.5 acre of dunesland along the Lake Michigan Coast between two units of the Illinois Beach State Park (IBSP) in Lake County, Illinois. A permit to collect Carex species was granted in 2013 with the purpose to complete the research of Carex growing in the Zion beach-ridge plain.  Ten species were discovered and included with the inventory of 53 Carex species growing in the Zion beach-ridge plain including IBSP, Spring Bluff, Chiwaukee Prairie, and Waukegan Harbor.


The Hosah Park dunesland is one mile long by a quarter mile north to south. A 1939 aerial map shows little disturbance except the Chicago Northwestern Railway that remains the western boundary.  Recent satellite images show Hosah Park has since been disturbed by ditching, channeling and a building of a radio tower with three anchor stations and an entry road that also give access to the radiation monitor for the power plant. While the railway was drawn in on the 1864 map, the west to east spur railway was added after the power plant was built in 1970’s. Some natural habitats remain and native Carex grew in sedge meadows and sand savannas, yet also in the blacktop crevices of the only road and disturbed soil of the railway right of way. Few specimens of Carex from Hosah Park are in Midwest Herbaria. These Carex went to Illinois State Museum and Illinois State Natural Survey as vouchers.


Hosah Park’s southern boundary is Shiloh Blvd on latitude N42 27’ 0”, an east-west road that is a  continuation of 25th Street that runs to Lake Michigan. The Zion Train Station was south of the western border at W87 49’ 4.8”, which is also the Union Pacific Railway that was formerly Chicago-Northwestern Railway until 1995. The northern boundary adjoins IBSP Camp Logan with a post and cable fence at N42 27 ‘ 10.8 “.

A spur railway south of the northern boundary at N42 27’ 10.6” crosses the park road and curves to the power plant. The Hosah Park parking lot across from the former Commonwealth Edison Power Station entry on Shiloh Blvd is W87 48’ 6”  at  the Lake Michigan coast. The large park sign  “Preservation Area” is beyond the parking lot northward at N42 27’ 1.65” and W87 48’ 6”. The sign is along a blacktop road that leads to a boardwalk to Lake Michigan and continues north to the IBSP North.

Geologic History

The city of Zion rests on the last glacial sediments from the Wisconsin Glacier 14,000 years ago when a lake much larger than the current Lake Michigan lapped at that beach approximately where the original Milwaukee to Chicago railroad tracks were laid prior to 1864. The lake level eventually fell to 182-176 meters and became Lake Michigan as we know it now. The exposed beach plain was higher than today and became a corrugated topography with sand ridges, some to 3 meters high. About 3,700 years ago, the beach aside today’s Kensosha began eroding away yet also building up again with wave deposited sand and gravel. The timeline is based on soil borings into the beach, foredunes and lake plain to the Holocene Ridge (Hester and Fraser 1973).

The wave washed beach in 2012 was the lowest recorded but was up again in 2013, almost 2 ‘ higher from snowmelt and rainfall, plus less evaporation. The foredune at Hosah Park has no rip-rap or armoring applied, in contrast to the Chiwaukee Prairie to the north and also the Illinois Dunes. The beach is composed of granitic and limestone sand with wave-rounded cobbles that were glacially transported from Wisconsin and Michigan and smoothed in the lapidary-like motions of Lake Michigan’s abrasive sands.


The sand savannas had mostly cottonwood, black and white oaks, and black cherry. The upland Carex species, C. pensylvanica, C. muhlenbergii, and C. siccata grew in the semi-shade of the savanna trees.

The wetlands were probably sedge meadows but now has masses of southern cattail with red dogwood shrubs and willows along the edges. C. pellita and C. stricta grew along these marshy edges. The wet prairie between the road and the foredune had C. crawei, C. tetanica, and C. buxbaumii.

C. bebbii, and C. brevior  grew in the road crevices in the blacktop and along the roadsides. C. brevior and C. muehlenbergii also grew along the railway right of way. All species were in the Curtis 2013 inventory of the Zion beach-ridge plain. Specimens were sent to two herbaria.


Ambroz, D. and Garness, K. 2012. Documented Flora of Illinois Beach State Park, Zion, Illinois and Spring Bluff, Winthrop Harbor, Illinois Department of Natural Resources.

Ball, P. W. and A. A. Reznicek. eds. Cyperaceae. Flora of North America, Volume 23:254-573. New York: Oxford University Press.

Coastal Management Program (ICMP). 2011. Illinois Beach State Park and North Point Marina including the Dead River and Kellogg Creek watersheds, 2011.

Cowles, H. C. 1899. The ecological relations of the vegetation on the sand dunes of Lake Michigan. Botanical Gazette 27(5):361–391.

Curtis, L. W. 1974. A vegetation analysis of Benedict Prairie, Kenosha County, Wisconsin. Master’s thesis, U-Wisconsin-Milwaukee.

Gates, F. C. 1912. The vegetation of the beach area in northeastern Illinois and southeastern Wisconsin. Bulletin of Illinois State Laboratory of Natural History 9:255–372.

Hester, N. C. and G. S. Fraser. 1973. Sedimentology of a beach ridge complex and its significance in land- uses planning. Illinois State Geological Survey, Environmental Geology Notes.

Kenosha County Interactive Mapping System. Kenosha County. Link no longer valid

Lake County GIS Mapping Division. 2012.

Lunn, E. 1982. Plants of the Illinois Dunesland. Illinois Dunesland Preservation Society.

Milde, M. 2012. Floristic Inventories of Waukegan Dunes and Beach and Adjacent Properties in Waukegan Harbor of Concern and Extended Study Area Work.

Mohlenbrock, R. H. 2011. 2nd Ed. The illustrated flora of Illinois—Sedges: Carex. Carbondale: Southern Illinois University Press.

Pepoon, H. S. 1927. An Annotated Flora of Chicago Area. Chicago: Chicago Academy of Science.

Plants of Concern, rare plant monitoring. Chicago Wilderness and Chicago Botanic Garden. www.

Swink, F. and G. Wilhelm. 1994. Plants of the Chicago region. 4th ed. The Morton Arboretum, Lisle, Illinois.

Waukegan Harbor Citizens Advisor Group map. http:// Restoration.jpg. Wiki Watershed Central.

Linda W. Curtis, author, botanist.


copyright © 2014 Linda Curtis, botanist

Comments are closed.