Code
CYPLX
Growth form
Sedge
Biological cycle
Vivacious
Habitat
Marshland / Terrestrial
Geographical area
America / Africa / Indian ocean / Asia / Oceania
Cyperus laxus Lam.
synonym | Cyperus diffusus subsp. tolucensis (Kunth) Borhidi |
synonym | Cyperus diffusus Vahl |
synonym | Cyperus diffusus var. tolucensis (Kunth) Kük. |
synonym | Cyperus diffusus var. umbrosus (Lindl. & Nees) Kük. |
synonym | Cyperus homoiiria Steud. |
synonym | Cyperus laxus subsp. laxus |
synonym | Cyperus limbatus Maury ex Micheli |
synonym | Cyperus macrostachyus Ten. ex Boeckeler |
synonym | Cyperus octophyllus Hochst. ex Steud. |
synonym | Cyperus tolucensis Kunth |
synonym | Cyperus umbrosus Lindl. & Nees |
No Data |
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Global description
Cyperus laxus is a vivacious sedge growing from a short rooted rhizome. The stem is trigonal, the leaves arranged tristically have sheaths nested at the base of the stem, the blade has a central gutter and is shorter than the stem. The inflorescence is formed of large umbels with long, fine rays ending in small umbellules with about twenty fasciculate lanceolate spikelets.
General habit
Cespitose and vivacious plant, 20 to 60 cm high.
Underground system
Short tuberous rhizome covered with dark scales. Fibrous roots.
Stem
The stem is trigonal, with obtuse angles, 2 to 4 mm in diameter. It is smooth and glabrous, green and shiny.
Leaf
The leaves are simple, linear lanceolate located at the base of the plant and arranged tristically. At the base is a closed, trigonal, glabrous sheath. The blade is less than or equal to the length of the stem, linear, 5 to 8 mm wide and has a characteristic gutter in the middle part. The summit is abruptly acute or acuminate, the margin is entire and smooth. Both sides are glabrous.
Inflorescence
The inflorescence is a large umbel of 10 to 30 cm in diameter, very loose, consisting of 8 to 12 fine rays 10 to 23 cm long, carrying at their end an umbellule of 7 to 9 short rays bearing ultimate umbellules of 3 to 6 even shorter rays. The rays are very spread out or even slightly drooping. At the base of the umbel are 7 to 10 leaf-like involucral bracts, similar in shape to the leaf blade, 20 to 60 cm long and 4 to 12 mm wide, often longer than the primary rays of the main umbel. Characteristically, the summit of the bracts is abruptly acuminate and terminates in a tapered tip. At the base of the umbellules are some linear bracts shorter than the rays. The spikelets of the umbellules are grouped in fascicles of 3 to 9. They are lanceolate, 6 to 12 mm long and 3 mm wide, including 10 to 24 flowers. The rachillet is closely winged. The glumes are oval, abruptly acute and mucronate, green on the back and hyaline or brownish on the sides, with 5 veins. 3 evergreen stamens, trifid style.
Fruit
The fruit is an oboval achene, a concave-faced trigononal with a slender base and a slightly apiculated apex, 1.5 mm long and 1 mm in diameter. The tegument is smooth and dark brown in color. The base of the style is very small.
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Cyperus laxus behaves as a permanent vivacious in warm regions with constant humidity throughout the year (such as northern Brazil or Guyana). On the other hand, it grows as an annual species in the southern regions of Brazil, with cooler temperatures in winter and a more pronounced dry period. It is multiplied by seed and vegetatively by rhizomes.
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
West Indies: Species present at low altitude.
Brazil: Cyperus laxus grows in moist soils that are temporarily flooded, especially in pre-Amazonian and Amazonian areas.
French Guiana: The species is present in the rich and humid soils of marshland, especially in vegetable crops in recently cleared plots, in rice fields and gardens.
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Origin
Cyperus laxus is native to South America.
Worldwide distribution
The species is present in the humid tropical regions of the American continent and the Caribbean. It is also present in Equatorial Africa and Asia.
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
- Fournet, J. (2002). Flore illustrée des phanérogames de Guadeloupe et de Martinique. Montpellier, France, Cirad, Gondwana éditions.
- Kissmann, K. G. (1997). Plantas Infestantes e Nocivas. Sao Paulo.
- Marnotte, P. and A. Carrara. (2007). "Plantes des rizières de Guyane." from http://plantes-rizieres-guyane.cirad.fr/.
- Berton, A. (2020). Flore spontanée des cultures maraichères et fruitières de Guyane. Guide de reconnaissance des 140 adventices les plus communes des parcelles cultivées. Cayenne, Guyane, FREDON Guyane: 186.https://portal.wiktrop.org/document/show/173
- Fournet, J. (2002). Flore illustrée des phanérogames de Guadeloupe et de Martinique. Montpellier, France, Cirad, Gondwana éditions.
- Kissmann, K. G. (1997). Plantas Infestantes e Nocivas. Sao Paulo.
- Marnotte, P. and A. Carrara. (2007). "Plantes des rizières de Guyane." from http://plantes-rizieres-guyane.cirad.fr/.
- Berton, A. (2020). Flore spontanée des cultures maraichères et fruitières de Guyane. Guide de reconnaissance des 140 adventices les plus communes des parcelles cultivées. Cayenne, Guyane, FREDON Guyane: 186.https://portal.wiktrop.org/document/show/173
Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Cyperus%2520laxus
Attributions | |
Contributors | |
Status | UNDER_CREATION |
Licenses | CC_BY |
References |
Root | Root |
Kingdom | Plantae |
Phylum | Tracheophyta |
Class | Liliopsida |
Order | Poales |
Family | Cyperaceae |
Genus | Cyperus |
Species | Cyperus laxus Lam. |