Carex intumescens (Bladder sedge)

Carex intumescens Rudge

Bladder sedge, greater bladder sedge, shining bur sedge, swollen sedge

Bladder sedge is a North American native. Often found near water, it is also found at forest edges.

Plant: Tufts are up to 2½′ (80 cm) high.

Leaves: Dark, parallel-veined, 4–10″ (10–25 cm) long, ⅛–¼″ (3.5–8 mm) wide.

Flowers: Inflorescences are ¾–6″ (2–15 cm) long. A narrow, dark brown staminate spike tops the culm, There are one to four nearly spherical or slightly cylindrical pistillate (female) spikes per stem. Each spike has 2-8 large teardrop-shaped perigynia, with the fat ends connected and the thin ends emerging in all directions. They appear from April to June.

Fruits: Each perigynium contains a single achene ⅛″ (5 mm) long.

Habitat: Floodplain woodlands, woodland paths, soggy thickets, sedge meadows, marshes, and ditches.

Similar species.

Online References:

Illinois Wildflowers

YouTube Video footage

The Lady Bird Johnson Wildflower Center

Flora of North America

References:

Arsenault, Matt; Mittelhauser, Glen H.; Cameron, Don; Dibble, Alison C.; Haines, Arthur; Rooney, Sally C.; and Weber, Jill E., Sedges of Maine: A Field Guide to Cyperaceae, University of Maine Press, 2013, p. 326

Jenkins, Jerry, Sedges of the Northern Forest: A Photographic Guide (The Northern Forest Atlas Guides), Comstock Publishing Associates, 2019, p. 55

Carex intumescens Rudge var. fernaldii L.H. Bailey

6/14/2019 · J. Harry Rich Trail, Groton, Massachusetts

6/26/2014 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 6 × 6″ (16 × 14 cm)

8/18/2010 · J. Harry Rich Woods, off Nod Rd., Groton, Massachusetts · ≈ 4½ × 3½″ (11 × 9.2 cm)

6/26/2014 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 6 × 5″ (15 × 12 cm)

9/29/2016 · Henry E. Cowdrey Nature Center, Lunenberg, Massachusetts

5/31/2016 · J. Harry Rich State Forest, Pepperell, Massachusetts

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 4 × 4½″ (10 × 12 cm)

6/13/2021 · Cathance River Nature Preserve, Topsham, Maine · ≈ 4½ × 7″ (11 × 17 cm)

6/14/2019 · J. Harry Rich Trail, Groton, Massachusetts

6/2/2010 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 5 × 7″ (13 × 17 cm)

6/2/2010 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 6 × 8″ (15 × 20 cm)

5/31/2016 · J. Harry Rich State Forest, Pepperell, Massachusetts

6/2/2010 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 11 × 7″ (27 × 18 cm)

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 6 × 8″ (14 × 19 cm)

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 7 × 11″ (18 × 27 cm)

6/13/2021 · Cathance River Nature Preserve, Topsham, Maine · ≈ 3 × 4″ (8.3 × 10 cm)

5/31/2016 · J. Harry Rich State Forest, Pepperell, Massachusetts

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 3½ × 5″ (9.2 × 13 cm)

7/3/2023 · Gettysburg National Military Park, Gettysburg, Pennsylvania

7/23/2017 · Pine Grove Furnace State Park, Pennsylvania · ≈ 8 × 5″ (20 × 13 cm)

6/15/2012 · Townsend State Forest, Townsend, Massachusetts · ≈ 6 × 4″ (15 × 10 cm)

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 4½ × 7″ (11 × 17 cm)

1/13/2026 · Highlands Trails, Topsham, Maine

6/26/2016 · Short Trail, Willard Brook State Park, Ashby, Massachusetts

1/5/2026 · Highlands Trails, Topsham, Maine

7/23/2017 · Pine Grove Furnace State Park, Pennsylvania · ≈ 7 × 4½″ (18 × 12 cm)

7/23/2017 · Pine Grove Furnace State Park, Pennsylvania · ≈ 4 × 6″ (11 × 16 cm)

7/3/2023 · Gettysburg National Military Park, Gettysburg, Pennsylvania

1/5/2026 · Highlands Trails, Topsham, Maine

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts · ≈ 17 × 12″ (44 × 29 cm)

6/9/2026 · Ladies Lookout, Pinkham Notch, New Hampshire · ≈ 4½ × 7″ (12 × 18 cm)

6/13/2021 · Cathance River Nature Preserve, Topsham, Maine · ≈ 6 × 4″ (15 × 10 cm)

6/2/2013 · Beaver Brook Conservation Area, Hollis, New Hampshire · ≈ 4½ × 5″ (11 × 13 cm)

Kingdom	Plantae	Plants, but not fungi, lichens, or algae (from Stearn's Botanical Latin)
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Liliopsida	Monocots (plants with a single seed leaf); includes the lily family
Subclass	Commelinidae	Dayflowers and spiderworts, and several others
Order	Cyperales	Flowering plants including grasses
Family	Cyperaceae	Sedge family
Genus	Carex	The “true” sedges
Species	intumescens	Latin for “swollen”

About plant names...

Range:

About this map...

Carex intumescens description by Thomas H. Kent, not updated.