| Carex | |
|---|---|
| Carex halleriana | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Monocots |
| (unranked): | Commelinids |
| Order: | Poales |
| Family: | Cyperaceae |
| Genus: | Carex L. |
| Type species | |
| Carex hirta L. [1] |
|
| Species | |
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Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. 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 as caricology.
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All species of Carex are perennials.[2] They typically have rhizomes, stolons or short rootstocks, but some species grow in tufts (caespitose).[2] The culm – the flower-bearing stalk – is unbranched and usually erect.[2] It is usually distinctly triangular in section.[2]
The leaves of Carex comprise a blade, which extends away from the stalk, and a sheath, which encloses part of the stalk.[2] The blade is normally long and flat, but may be folded, inrolled, channelled or absent.[2] The leaves have parallel veins, and where the blade meets the culm, there is a structure called the ligule.[2]
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.[2] Almost all Carex species are monoecious; each flower is either male (staminate) or female (pistillate).[2] 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.[3] 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 that surrounds each female flower.[3] 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.[3] The shape, venation, and vestiture (hairs) of the perigynium are important structures for distinguishing Carex species.
The fruit of Carex is a dry, one-seeded indehiscent achene or nut[2] which grows within the perigynium. Perigynium features aid in fruit dispersal.
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 – where they are often the dominant vegetation.[3]
Carex species and cultivars are well represented in the horticulture industry, landscape design projects, and private gardens.[4] Native species are used in wildland habitat restoration projects, Natural landscaping and gardens, and in sustainable landscaping as drought tolerant grass replacements for lawns and garden meadows.[5][6] Both ornamental cultivars (many from Japan) and native species selections are used as perennials in traditional gardens.[7]
The genus Carex was established by Carl Linnaeus in his work Species Plantarum in 1753, and is one of the largest genera of flowering plants.[8] Estimates of the number of species vary from about 1100 to almost 2000.[9] Species include:
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).[10] (Sennegras is one of the names, for such mixes.[11]) 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).[12]