E-Flora BC: Electronic Atlas of the Flora of British Columbia

Carex macrocephala Willd. ex Spreng.
large-headed sedge (big-headed sedge)
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Dawn Hanna  Email the photographer   (Photo ID #10551)

E-Flora BC Static Map
Distribution of Carex macrocephala
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Introduction

Large-headed sedge is a distinctive coastal species of perennial, rhizomatous sedge that is found in North America and Asia in coastal dunes and beaches. In North America, it is restricted to the Pacific Coast, where it is reported from Alaska, British Columbia, Washington and Oregon (USDA 2011). It has also been reported from New Jersey (Wooton 2007) where it is potentially invasive. In British Columbia, this species has been reported along the coast from the US border north to Haida Gwaii.

This is an easily recognized, low-growing (10-30 cm tall) species of Carex that stands out in beach/dune habitats and is usually dominant. It may be found with other beach/dune specialists such as beach pea (Lathyrus japonicus var. maritimus). The large brown seed heads and sharply angled stems are distinctive.

Populations of this species may be viewed in the Vancouver area at Iona Beach Regional Park (Richmond) and Boundary Park Regional Park (Delta).

Species Information

Click on the image below to view an expanded illustration for this species.



General:
Perennial herb from long, spreading rhizomes; stems 10-30 cm tall, arising singly or a few together, usually shorter than the leaves.
Leaves:
Sheaths brownish or blackish, breaking into threads at the bases, persistent; blades 2 to 5 per stem, channeled, gradually tapering to the tips, 4-8 mm wide.
Flowers:
Spikes either male or female, unstalked, the male inflorescence with many aggregated spikes in a cylindrical, 3.5- to 5-cm long by 1- to 1.5-cm wide head, the female inflorescence with many aggregated spikes in a cylindrical to egg-shaped, 3.5-8 cm long by 2.5-5 cm wide head; bracts lacking in the male inflorescence, the female inflorescence with several to numerous bracts enlarged at the bases, with small-bristled teeth, up to 6 cm long.
Fruits:
Perigynia lanceolate to egg-shaped, 1-1.5 cm long, 4-6 mm wide, brownish to brownish-yellow, plano-convex, with small-bristled teeth above, shiny, strongly nerved on both faces, crowded, ascending to spreading, short-stalked, the beaks 5-7 mm long, as long as the bodies of the perigynia, bidentate; female scales egg-shaped, dark to light brown, with translucent margins, usually shorter and narrower than the perigynia; stigmas 3; achenes lens-shaped, 3.5-4 mm long.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Sand beaches and dunes in the lowland zone; infrequent in coastal BC; amphiberingian, N to AK and S to OR; coastal E Asia.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Carex macrocephala

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Minimum

Average

Maximum

Elevation (metres) 0 818 1970
Slope Gradient (%) 0 15 72
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
42 189 270
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 3 7
Modal Nutrient Regime
Class
C
Number of field plots
 species was recorded in:
15
Modal BEC Zone Class
CWH
All BEC Zones (# of stations/zone) species was recorded in: BAFA(2), BWBS(1), CWH(5), ESSF(1), SBS(3), SWB(3)

Climate

The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is cool mesothermal.

Synonyms and Alternate Names

Carex anthericoides
Carex macrocephala subsp. anthericoides

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

Species References

Wooton, Louise. 2007. First Report of Carex macrocephala in Eastern North America with Notes on Its Co-Occurrence with Carex kobomugi in New Jersey. Journal of the Torrey Botanical Society 134 (1): 126-134.

General References