Home Cyperaceae Carex

Carex intumescens Rudge

Common Name: SEDGE
Coefficient of Conservatism: 3
Coefficient of Wetness: -3
Wetness Index: FACW
Physiognomy: Nt P-Sedge

A common species of swamps and thickets, including swamps, depressions and stream banks in oak and beech-maple forests (as well as upland sites); less often in coniferous swamps (cedar, tamarack, spruce, fir), especially along borders, roads, and clearings.

In addition to the features noted in the key, immature specimens with crowded spikes (appearing as if one) might be confused with C. lupulina, from which they differ in having the inner surfaces of the teeth at the end of the perigynium usually hispid; in C. lupulina the teeth are ± smooth within. Depauperate specimens of C. lupulina with mature achenes can also be distinguished, because the achenes of C. intumescens are plump, with the sides elliptic or obovate, while those of C. lupulina have the sides rhombic.

Plants range from having dense inflorescences of numerous broadly ovoid, inflated perigynia, with the lowest reflexed (at a glance looking a bit like Carex grayi), to few-fruited plants with narrow, lance-ovoid perigynia. These latter have been called var. fernaldii L.H. Bailey, and occur sparsely throughout the state. The significance of this variation within Michigan is unclear.

L. Wallis

Click image to view gallery

Counties
Alcona
Alger
Allegan
Alpena
Antrim
Arenac
Baraga
Barry
Bay
Benzie
Berrien
Calhoun
Cass
Charlevoix
Cheboygan
Chippewa
Clare
Clinton
Crawford
Delta
Dickinson
Eaton
Emmet
Genesee
Gogebic
Grand Traverse
Gratiot
Hillsdale
Houghton
Huron
Ingham
Ionia
Iosco
Iron
Jackson
Kalamazoo
Kalkaska
Kent
Keweenaw
Lake
Lapeer
Leelanau
Lenawee
Livingston
Luce
Mackinac
Macomb
Manistee
Marquette
Mason
Mecosta
Menominee
Midland
Missaukee
Monroe
Montcalm
Montmorency
Muskegon
Newaygo
Oakland
Oceana
Ogemaw
Ontonagon
Osceola
Oscoda
Ottawa
Presque Isle
Roscommon
Saginaw
Sanilac
Schoolcraft
Shiawassee
St. Clair
St. Joseph
Tuscola
Van Buren
Washtenaw
Wayne
Wexford

Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March, 17, 2025
https://lsa-miflora-p.lsait.lsa.umich.edu/#/record/986