Lenticular sedge (Carex lenticularis)

Description

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Lenticular sedge fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
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Lenticular sedge description

The lenticular sedge (Carex lenticularis) is a perennial North American plant which grows in dense clumps in moist habitats ^{(2) (3) (4) (5)}. Its smooth, pale yellow-green stems, known as ‘culms’, are slender, erect and three-sided ^{(2) (3) (5) (6)}, and each stem usually bears around four to nine pale grey-green leaves ⁽⁵⁾. The leaves of the lenticular sedge are quite narrow, measuring up to about four millimetres in width. The part of the leaf that wraps around the stem, known as the ‘leaf sheath’, may be brownish or have brownish spots ^{(2) (3)}.

As in other members of the sedge family (Cyperaceae), the lenticular sedge has small, inconspicuous flowers which are arranged in erect ‘spikes’ ⁽⁷⁾. The spikes of the lenticular sedge are narrowly cylindrical ⁽⁵⁾, measuring up to about 6 centimetres in length and 0.6 centimetres in width ⁽²⁾. Groups of four to six spikes are usually clustered together to form an inflorescence ⁽⁵⁾, with the lower spikes of the inflorescence generally bearing female flowers and the outermost spike bearing male flowers. However, the outermost spike may also have a few female flowers at the tip, and the middle spikes may have some male flowers at the base ^{(2) (3) (5) (6)}.

The fruit of the lenticular sedge is a dry, brown, one-seeded achene ⁽⁵⁾. As in other Carex species, the achene of the lenticular sedge is enclosed within a sac-like structure known as a ‘perigynium’, which in this species is pale green, veined, and measures up to 3.5 millimetres in length ^{(2) (3) (5) (6)}. The oval or lens-like shape of the perigynium gives the lenticular sedge its scientific name, lenticularis, meaning ‘like a lens’ ⁽⁵⁾.

Five different varieties of the lenticular sedge are recognised: Carex lenticularis var. dolia (Enander’s sedge), Carex lenticularis var. impressa, Carex lenticularis var. lenticularis, Carex lenticularis var. limnophila and Carex lenticularis var. lipocarpa (Kellogg’s sedge) ^{(1) (2) (4)}.

Also known as

Enander’s sedge, fewrib sedge, Kellogg sedge, Kellogg’s sedge, lakeshore sedge, lens-fruited sedge, shore sedge, tufted sedge.

Synonyms

Carex enanderi, Carex eurystachya, Carex hindsii, Carex kelloggii, Carex plectocarpa.

Size

Stem length: up to 90 cm ^{(2) (3)}

Lenticular sedge biology

Like other Carex species, the lenticular sedge has unisexual flowers, with each individual flower containing either male or female reproductive organs ⁽⁷⁾. The flowers of the lenticular sedge are produced in late spring ^{(4) (5)}, with the fruits appearing from July to September ⁽²⁾. The seeds of this species are commonly eaten by small birds ⁽⁵⁾.

A perennial species, the lenticular sedge usually lives for more than two years. It can grow new shoots from underground stems known as rhizomes ^{(5) (7)}.

Lenticular sedge range

A North America species, the lenticular sedge is found from Alaska, across Canada, and south into the western and north-eastern United States ^{(2) (4)}. Its range reaches as far south as California, Arizona, Utah and Colorado in the west, and Minnesota, Wisconsin, Michigan, New York and Massachusetts in the east ^{(2) (3) (4) (6)}.

Lenticular sedge habitat

The lenticular sedge usually occurs in wet conditions around the shores of lakes and rivers, as well as in wet meadows and marshes ^{(2) (3) (5)}. It is found at elevations up to about 3,000 metres ⁽²⁾.

Lenticular sedge status

The lenticular sedge has yet to be classified by the IUCN.

Lenticular sedge threats

The lenticular sedge is listed as ‘Threatened’ in Massachusetts and Wisconsin ⁽⁴⁾. However, very little information is available on the threats faced by this plant, and its conservation status has yet to be assessed by the IUCN ⁽⁸⁾.

Lenticular sedge conservation

There are no known specific conservation measures currently targeted at the lenticular sedge.

Find out more

Find out more about the lenticular sedge:

• Flora of North America - Carex lenticularis:
  http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357284

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Glossary

Achene

A simple single-seeded fruit that falls from the plant in one piece. Achenes usually in occur in clusters.

Inflorescence

The reproductive shoot of a plant, which bears a group or cluster of flowers.

Perennial

A plant that normally lives for more than two seasons. After an initial period, the plant produces flowers once a year.

Rhizome

An underground, horizontal plant stem that produces roots and shoots.

Variety

In taxonomy, the science of classifying organisms, variety is the rank below subspecies. Members of a variety differ from others of the same species in relatively minor ways.

References

1. Integrated Taxonomic Information System (ITIS) (July, 2011)
   http://www.itis.gov/
2. Flora of North America - Carex lenticularis (July, 2011)
   http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357284
3. Cody, W.J. (2000) Flora of the Yukon Territory. Second Edition. NRC Research Press, Ottawa, Ontario.
4. USDA PLANTS Database - Lakeshore sedge, Carex lenticularis (July, 2011)
   http://plants.usda.gov/java/profile?symbol=CALE8
5. Kershaw, L., Gould, J., Johnson, D. and Lancaster, J. (2001) Rare Vascular Plants of Alberta. University of Alberta Press, Edmonton, Alberta.
6. Britton, N.L. and Brown, A. (1913) An Illustrated Flora of the Northern United States, Canada and the British Possessions - from Newfoundland to the Parallel of the Southern Boundary of Virginia, and from the Atlantic Ocean westward to the 102D Meridian. Volume 1. Charles Scribner’s Sons, New York.
7. Heywood, V.H. (1978) Flowering Plants of the World. Oxford University Press, Oxford.
8. IUCN Red List (July, 2011)
   http://www.iucnredlist.org/