COMMON NAME

Japanese sedge
Asiatic sand sedge


FULL SCIENTIFIC NAME

Carex kobomugi Ohwi.


FAMILY NAME COMMON

Sedge family


FAMILY SCIENTIFIC NAME

Carex kobomugi


IMAGES


Habit

Close-up of inflorescence

Incursion

Habitat/Incursion

Habitat/Incursion

NOMENCLATURE/SYNONYMS

Synonyms: None


DESCRIPTION

Botanical Glossary

Carex kobomugi is a perennial sedge that grows 10-30 cm (4 in.-1 ft.) in height. The plant is very stout and has an overall yellow-green color. The slightly arching leaves are very stiff and measure 3-6 mm (0.1-0.25 in.) in width. The margins of the leaves are rough to the touch, and the serration can be seen with the aid of a hand lens (10x). These leaves are often longer than the triangular stems. Carex kobomugi flowers in May to June. It is dioecious, therefore there are separate male and female plants. There are many flower spikes on this plant that appear as one large spike. The staminate (male) spikes are cylindrical in shape and measure 3-4 cm (1-1.5 in.) long and 1-2 cm (0.4-0.75 in.) wide. The pistilate (female) spikes are more ovoid in shape and measure 3-6 cm (1-2.25 in.) long and 2-4 cm (0.75-1.5 in.) wide. The perigynia are erect and dark brown in color, lance-ovate to elliptic in shape and measures 10-14 mm (0.4-0.5 in.) in length. The beak of the perigyna is smooth, bidentate and can measure nearly as long as the rest of the structure. The achene contained within the perigynium is trigonous in shape and measures 4-7 mm (0.15-0.25 in.) long. Page References Fernald 303, Gleason & Cronquist 709, Holmgren 661,Magee & Ahles 267. See reference section below for full citations.


SIMILAR SPECIES

Ammophila breviligulata Fern. (American beachgrass)
Panicum amarum Elliott (bitter panicum) Ammophila breviligulata has dense inflorescences that measure 10-40 cm (4-15 in.) long and 1-2.5 cm (0.4-1 in.) wide, and its leaves are 2-ranked. Panicum amarum is glaucous and also has 2-ranked leaves.


REPRODUCTIVE/DISPERSAL MECHANISMS

Carex kobomugi has mechanically dispersed seeds. However, these seeds have a low germination rate, and seedlings are rarely seen. Usually this plant spreads locally by means of extensive rhizomes.


DISTRIBUTION

Carex kobomugi is native to coastal Japan, China and Korea. In the United States it has been reported down the east coast from Massachusetts to North Carolina, and also in Oregon. In New England this plant has been found in Massachusetts (historically) and Rhode Island.


HISTORY OF INTRODUCTION IN NEW ENGLAND

The first report of Carex kobomugiin the US was from Island Beach State Park, New Jersey in 1929. It was thought that perhaps it came ashore from shipwrecks that were carrying oriental porcelain, with this plant as a packing material. Soon after the plant was observed to be potentially good for the stabilization of dunes, and thus it was planted intentionally on the dunes in New Jersey and other beaches on the east coast. This plant likely made its way to New England through either intentional planting or the water dispersal of plant fragments or seeds.


HABITATS IN NEW ENGLAND

Coastal Beach or Dune

Carex kobomugi is found on the upper dunes of sandy beaches, and in sand pits near the coast.


THREATS

Carex kobomugi has the ability to form dense stands on coastal dunes. It has been found in densities of up to 200 plants per square meter. This density effectively excludes the native beach grass, Ammophila breviligulata. Carex kobomugi actually makes dunes more susceptible to being blown out, and the native plant diversity found with this sedge is less than with the native beach grass.


MANAGEMENT LINKS

Plant Conservation Alliance
Fact sheet including management information


DOCUMENTATION NEEDS

Documentation required: Specimen in fruit
Best time for documentation: Mid-summer


ADDITIONAL INFORMATION

Integrated Taxonomic Information System
Taxonomic information about the species

PLANTS Database
General information and map

Plant Conservation Alliance
Fact sheet

Geological Society of America
Description of this plant in New Jersey


REFERENCES

Fernald, M.L.  1950.  Gray's Manual of Botany 8th edition.  American Book Company, New York.

Gleason, H.A. and A.C. Cronquist.  1991.  Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed.  New York Botanical Garden, Bronx, New York.

Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual.  New York Botanical Garden, Bronx, New York.

Magee, D.W and H.E. Ahles. 1999.  Flora of the Northeast. University of Massachusetts Press, Amherst.

Newcomb, N. 1977.  Newcomb's Wildflower Guide.  Little Brown, Boston.

Small, J.A.  1954.  Carex kobomugi at Island Beach, New Jersey.  Ecology 35(2): 289-291.

USDA, NRCS.  2001.  The PLANTS Database, Version 3.1. (http://plants.usda.gov).  National Plant Data Center, Baton Rouge, LA 70874-4490 USA.