CAREX is a vast genus of almost 2,000 species of grassy plants in
Cyperaceae , commonly known as sedges (or seg, in older
books). Other members of the
Cyperaceae family are also called sedges,
however those of genus
Carex may be called "true" sedges, and it is
the most species-rich genus in the family. The study of
Carex is known
* 1 Description
* 2 Ecology and distribution
* 3 Taxonomy and cytogenetics
* 4 Uses
* 5 References
* 6 External links
All species of
Carex are perennial , although some species, such as
C. bebbii and C. viridula can fruit in their first year of growth, and
may not survive longer. They typically have rhizomes , stolons or
short rootstocks , but some species grow in tufts (caespitose ). The
culm – the flower-bearing stalk – is unbranched and usually erect.
It is usually distinctly triangular in section.
The leaves of
Carex comprise a blade, which extends away from the
stalk, and a sheath, which encloses part of the stalk. The blade is
normally long and flat, but may be folded, inrolled, channelled or
absent. The leaves have parallel veins and a distinct midrib. Where
the blade meets the culm there is a structure called the ligule . The
colour of foliage may be green, red or brown, and "ranges from fine
and hair-like, sometimes with curled tips, to quite broad with a
noticeable midrib and sometimes razor sharp edges". In this
Carex panicea , the upper spike contains male flowers, and the lower
spike contains female flowers.
The flowers of
Carex are small and are combined into spikes , which
are themselves combined into a larger inflorescence . The spike
typically contains many flowers, but can hold as few as one in some
species. Almost all
Carex species are monoecious ; each flower is
either male (staminate) or female (pistillate). A few species are
dioecious. Sedges exhibit diverse arrangements of male and female
flowers. Often, the lower spikes are entirely pistillate and upper
spikes staminate, with one or more spikes in between having pistillate
flowers near the base and staminate flowers near the tip. In other
species, all spikes are similar. In that case, they may have male
flowers above and female flowers below (androgynous) or female flowers
above and male flowers below (gynecandrous). In relatively few
species, the arrangement of flowers is irregular.
The defining structure of the genus
Carex is the bottle-shaped bract
surrounding each female flower. This structure is called the
perigynium or utricle, a modified prophyll. It is typically extended
into a "rostrum" or beak, which is often divided at the tip (bifid)
into two teeth. The shape, venation, and vestiture (hairs) of the
perigynium are important structures for distinguishing
The fruit of
Carex is a dry, one-seeded indehiscent achene or nut
which grows within the perigynium. Perigynium features aid in fruit
ECOLOGY AND DISTRIBUTION
Carex species are found across most of the world, albeit with few
species in tropical lowlands, and relatively few in sub-Saharan Africa
. Most (but not all) sedges are found in wetlands – such as marshes
, calcareous fens , bogs and other peatlands , pond and stream banks ,
riparian zones , and even ditches. They are one of the dominant plant
groups in arctic and alpine tundra , and in wetland habitats with a
water depth of up to 50 cm (20 in).
TAXONOMY AND CYTOGENETICS
List of Carex species
Carex was established by
Carl Linnaeus in his work Species
Plantarum in 1753, and is one of the largest genera of flowering
plants . Estimates of the number of species vary from about 1100 to
Carex displays the most dynamic chromosome evolution of
all flowering plants. Chromosome numbers range from n = 6 to n = 66,
and over 100 species are known to show variation in choromosome number
within the species, with differences of up to 10 chromosomes between
Carex has been divided into subgenera in a number of ways. The most
Georg Kükenthal 's classification using four
subgenera – Carex, Vignea, Indocarex and Primocarex – based
primarily on the arrangement of the male and female flowers. There
has been considerable debate about the status of these four groups,
with some species being transferred between groups and some authors,
Kenneth Kent Mackenzie , eschewing the subgenera altogether
and dividing the genus directly into sections . The genus is now
divided into around four subgenera, some of which may not, however, be
Carex subg. Carex – 1450 species, distributed globally
Carex subg. Psyllophora (Degl.) Peterm. (equivalent to
Kükenthal's "Primocarex") – 70 species
Carex subg. Vignea (P. Beauv. ex T. Lestib.) Peterm. – 350
Carex subg. Vigneastra (Tuckerman) Kükenthal (equivalent to
Kükenthal's "Indocarex" ) – 100 species, tropical and subtropical
Carex species and cultivars are popular in horticulture ,
particularly in shady positions. Native species are used in wildland
habitat restoration projects, natural landscaping , and in sustainable
landscaping as drought-tolerant grass replacements for lawns and
garden meadows . Some require damp or wet conditions, others are
relatively drought-tolerant. Propagation is by seed or division in
A mix of dried specimens of several species of
Carex (including Carex
vesicaria ) have a history of being used as thermal insulation in
footwear (such as skaller used by
Sami people and
Finneskoe by Lapps
Sennegrass is one of the names for such mixes. During the first
human expedition to the South Pole in 1911, such a mix were used in
skaller, when camps had been set (after each stretch of travelling had
been completed). Carsten Borchgrevink of the British Antarctic
Expedition 1898-1900 reported “I found the
Lapps method of never
using socks in their Finn boots answered well. Socks are never used in
Finnmarken in winter time, but ‘senne grass’ which they, of
course, had a special method of arranging in the ‘komager’ (Finn
boots) … if you get wet feet while wearing the grass in the
‘komager’ you will be warmer than ever, as the fresh grass will,
by the moisture and the heat of your feet, in a way start to burn or
produce its own heat by spontaneous combustion. The great thing seems
to be to arrange the grass properly in the boots, and although we all
tried to imitate the Finns in their skill at this work, none of us
felt as warm on our feet as when they had helped us.”
Species serve as a food source for numerous animals, and some are
used as a livestock hay.
* ^ Ilkka Kukkonen; Heikki Toivonen (1988). "Taxonomy of wetland
Aquatic Botany . 30 (1–2): 5–22. doi
* ^ Andrew L. Hipp (2007). "Nonuniform processes of chromosome
evolution in sedges (Carex: Cyperaceae)" (PDF ). Evolution . 61 (9):
2175–2194. PMID 17767589 . doi :10.1111/j.1558-5646.2007.00183.x .
* ^ A B C D E F G H I J Robert H. Mohlenbrock; Paul Wayne Nelson
(1999). "Introduction". Sedges: Carex. Volume 14 of The Illustrated
flora of Illinois.
Southern Illinois University Press . pp. 3–7.
ISBN 978-0-8093-2074-5 .
* ^ A B C D E F Peter W. Ball; A. A. Reznicek (2002). "Carex
Linnaeus, Sp. Pl. 2: 972. 1753; Gen. Pl. ed. 5, 420. 1754".
Magnoliophyta: Commelinidae (in part): Cyperaceae. Flora of North
America North of Mexico . 23.
Oxford University Press
Oxford University Press . pp. 254–258.
ISBN 978-0-19-515207-4 .
* ^ Amjad Almusaed (2010). Biophilic and Bioclimatic Architecture:
Analytical Therapy for the Next Generation of Passive Sustainable
Architecture. Springer . p. 52. ISBN 978-1-84996-534-7 .
* ^ A B C D A. C. Jermy; D. A. Simpson; M. J. Y. Foley; M. S.
Porter (2007). "General structure of Cyperaceae". Sedges of the
British Isles. BSBI Handbook No. 1 (3rd ed.). Botanical Society of the
British Isles . pp. 2–26. ISBN 978-0-901158-35-2 .
* ^ David G. Frodin (2004). "History and concepts of big plant
genera". Taxon . 53 (3): 753–776.
JSTOR 4135449 . doi
* ^ Andrew L. Hipp; Paul E. Rothrock; Eric H. Roalson (2009). "The
evolution of chromosome arrangements in
Carex (Cyperaceae)" (PDF ).
The Botanical Review . 75 (1): 96–109. doi
* ^ A B C Julian R. Starr; Stephen A. Harris; David A. Simpson
(2008). "Phylogeny of the unispicate taxa in
Cyperaceae Tribe Cariceae
II: the limits of Uncinia". In Robert F.; nbsp; C. Naczi; Bruce A.
Ford. Sedges: Uses, Diversity, and Systematics of the
proof). Monographs in Systematic Botany. 180. Missouri Botanical
Garden Press . ISBN 978-1-930723-72-6 .
* ^ A B C Dai Lunkai; Liang Songyun; Zhang Shuren; Tang Yancheng;
Tetsuo Koyama; Gordon C. Tucker. "33.
Carex Linnaeus, Sp. Pl. 2: 972.
1753. 薹草属 tai cao shu". Acoraceae through
Cyperaceae (PDF ).
Flora of China . 23.
Harvard University Press . pp. 285–461.
* ^ Judy Lowe (2012). "Carex". Tennessee & Kentucky Garden Guide:
the Best Plants for a Tennessee or Kentucky Garden (2nd ed.). Cool
Springs Press . p. 178. ISBN 978-1-59186-537-7 .
* ^ Frances Tenenbaum, ed. (2003). "Carex". Taylor's Encyclopedia
of Garden Plants.