You are here
Monocotyledons / Monocotiledóneas
Cenchrus ciliaris L.
EOL Text
Perennial, tufted or shortly rhizomatous. Culms erect or ascending from a decumbent or stoloniferous base, slender to moderately stout, sometimes much branched, up to 1 m tall. Leaf sheaths glabrous or pubescent; leaf blades linear, green or grayish, 10–50 × 0.4–0.8 cm, with scattered, tubercle-based hairs; ligule 0.5–3 mm. Inflorescence 3–15 cm, densely bristly, burrs contiguous, rachis puberulous. Burrs composed of many bristles; bristles antrorsely barbed; inner bristles 7–14 mm (one stouter and slightly longer), connate at extreme base to form a shallow disc 0.5–1.5 mm wide, somewhat flattened around spikelets, grooved on outer face, ciliate on inner margins, tips extended into flexuous bristles clearly exceeding spikelets; outer bristles numerous, shorter, slender. Spikelets 1–4 in burr, 3–5 mm; lower glume 1/3–1/2 spikelet length; upper glume ca. 1/2 spikelet length. 2n = 36.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242311755 |
More info on this topic.
More info for the terms: cover, natural, shrubs, tree
Buffelgrass is a pioneer species on disturbed sites [19,25,47,132] and can also establish and spread on undisturbed sites in the Sonoran Desert of northern Mexico and southern Arizona [17,18,50,89]. In the Sonoran Desert, buffelgrass is able to persist and alter native successional patterns [17,18]. On the Desert Laboratory grounds of Tucson, Arizona, buffelgrass displaced brittle bush on some rocky slopes where "considerable mortality" of brittle bush seems to have been caused by freezing. Both species exploit the upper soil horizons for moisture, but buffelgrass is active during the warm season, while brittle bush is active in late winter and spring. Nonetheless, brittle bush is unable to reestablish in areas dominated by buffelgrass [17].
A review and case study by Burquez and others [18] from the mid 1990s describes how buffelgrass is actively invading natural desert scrub and thornscrub communities in the Sonoran Desert in Sonora, Mexico. Thirty years after its introduction to northwestern Mexico, where about 4 million acres (1.6 million ha) were purposely cleared for its cultivation [50], buffelgrass is altering the landscape at a rapid pace (as happened to sizeable areas of northwestern Australia; see Cox and others [30] and Ibarra and others [78]). Buffelgrass was originally established by entirely clearing the native desertscrub with chains and bulldozers. More recent government directives required leaving 20% of the original tree cover in the plains and 100% along water courses; however, buffelgrass can spread into these areas and become dominant. It is well established outside of cultivation in native communities in central Sonora, and spreading northward [18].
The process of buffelgrass invasion begins along roads and near converted grasslands. Pure stands of buffelgrass are widely distributed along major Sonoran highways, where they are well watered by runoff from the pavement and produce abundant seed almost continuously throughout the year. This seed is easily dispersed into native desert scrub where buffelgrass readily establishes in cracks in the cryptogamic crust. When it spreads into native desert, it replaces native plant species and leads to an Âoverwhelming increase in the uncommon desert fires. Fire favors continued persistence and spread of buffelgrass over native desert plants (see FIRE REGIMES). Burquez and others [18] assert that the increased incidence of fire, coupled with disturbance by cattle and a marginal advantage in water use by buffelgrass can shift the dominance from desert arborescent forms to desert grasslands dominated by buffelgrass in the deep alluvial soils of central Sonora.
Fire: Buffelgrass can tolerate burning better than most long-lived perennials in the Sonoran Desert. Frequent fires allow buffelgrass to persist and spread to the detriment of native species [17,19,43,97,115,126]. In Texas, where buffelgrass primarily occurs as a cultivated species, native shrubs, given time, are able to establish in buffelgrass pastures. Prescribed fires are used in cultivated fields in Texas to suppress native shrubs and facilitate buffelgrass growth [62,63].
Shade: Buffelgrass is shade tolerant, and shade may promote its growth on some sites. In a controlled study in Hawaii, buffelgrass grew taller and had greater dry shoot weight under increasing shade, whether grown alone or with other grasses (sourgrass (Digitaria insularis) and guineagrass (Urochloa maxima)) [104].
1.8 Usos de la especie
En áreas donde se reporta como especie invasora es usado como ornamental y forrajero principalmente se utiliza para pastoreo directo y heno. Su crecimiento es muy rápido y produce abundante forraje. Cuando se cultiva en superficies grandes se puede henificar en pacas, las cuales se pueden conservar para las épocas críticas o de sequía (Cantú-Brito, 2006; Herrera-Arrieta &Pámanes, 2006).
Agropecuario
Produce abundante forraje de buena calidad cuando verde, en seco sus nutrimentos decrecen, por lo que se sugiere suplementar al ganado en épocas de sequía ó invierno (Villegas et al., 1998).
License | http://creativecommons.org/licenses/by-nc-sa/2.5/ |
Rights holder/Author | CONABIO |
Source | No source database. |
Pennisetum ciliare (Linnaeus) Link.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242311755 |
More info for the terms: apomixis, breeding system, cactus, culm, fresh, natural
Buffelgrass reproductive morphology varies among forms. Buffelgrass regenerates primarily via seeds [19,48,72,79,121,126]. At least 2 cultivars, 'Nueces' and 'Llano', regenerate from rhizomes [110]. Several authors note that buffelgrass may have rhizomes, although particular strains or cultivars are not specified [38,48,71,121,131]. Some forms also have tillers [75,113,122]. Duke [38] and Hickman [71] describe buffelgrass forms that reproduce via stolons.
Breeding system: The breeding system of buffelgrass varies, with both sexual and asexual reproduction occurring depending upon form. Some forms reproduce solely by sexual means. Buffelgrass is predominantly apomictic [17,36,72,110,118,129,131,135]. In Kenya, part of buffelgrass' natural range, six "varieties" of buffelgrass were grown together from 1956 to 1958 to test apomixis. At the end of the study no interbreeding had occurred, indicating apomixis [8]. Although most buffelgrass forms are obligate apomicts, research shows that facultative apomixis also occurs [72,129].
Pollination: Buffelgrass plants that reproduce sexually are wind-pollinated [11].
Seed production: Buffelgrass can begin producing seeds at approximately 3 months of age [135].
Two rhizomatous cultivars, 'Nueces' and 'Llano', also produce seeds but produce fewer seeds than forms without rhizomes [110,131]. Of the 2 cultivars, 'Llano' is the least productive [110].
Seed dispersal: Buffelgrass seeds are light, "fluffy", umbrella-like, and dispersed primarily by wind and water [18,19,79,136]. A review reported that buffelgrass seeds would be dispersed 2 to 23.8 feet (0.60-7.26 m) at wind speeds of 8.2 to 30 feet (2.5-10 m)/second [22].
Barbed bristles on buffelgrass seed coats allow for long-distance dispersal in animal skin and fur. Motor vehicles also disperse buffelgrass seed [18,19,22]. In Organ Pipe Cactus National Monument, Arizona, wind and vehicles are the primary dispersal mechanisms that bring buffelgrass in from Mexico. Secondary dispersal agents are feral livestock, native mammals, and humans crossing the United States-Mexico border [111].
Buffelgrass is not likely dispersed in cattle feces. In controlled experiments, buffelgrass seeds fed to cattle did not germinate following passage through the digestive tract [51,52].
Seed banking: At the time of this writing (2008), no information was available on buffelgrass seed banks.
Germination: Buffelgrass seed germination depends upon temperature, dormancy, depth of burial, moisture, and seed size. Under appropriate environmental conditions, buffelgrass seed can germinate at any time of year.
The minimum temperature required for buffelgrass germination is 54.5 °F (12.5 °C) [81,115]. In a greenhouse study, 16% to 30% of buffelgrass seeds germinated after 14 days at temperatures ranging from 59 to 90 °F (15-32 °C), with a 24 hour average of 75 °F (24 °C) [70]. A review stated that buffelgrass seeds required high temperatures (100 °F (60 °C)) for a period of 12 weeks to produce 80% germination [6].
Heat may kill buffelgrass seeds. Those that survive have a high germination rate but may have low survival. Following collection from the field, buffelgrass seeds from southeastern Botswana were exposed to 200 °F (100 °C) and 241 °F (116 °C) for 2 minutes in an oven. All buffelgrass seeds exposed to a temperature of 241 °F (116 °C) for 2 minutes were killed. The average percent (SD) germination of seeds heated to 200 °F (100 °C) was 90.2% (3.0) and unheated seeds was 95.5% (3.5). One month after germination, seedling survival for heated seeds was 16.9% (3.1), compared to 100% for unheated seeds [40].
Fresh buffelgrass seeds germinate poorly, reportedly due to physiological and embryo dormancy [6]. Dormancy is broken by a period of "rest" or weathering scarification that removes the seed coat. Letting seeds age 6 to 10 months improves germination [76]. On a Botswana savanna, buffelgrass seeds remain in the spikelet through ripening and dispersal. Dormancy may be induced by chemical and/or physical constraints of the surrounding spikelet [41].
In the greenhouse, buffelgrass seeds germinated best when lying on the soil surface. Germination success decreased with increasing planting depths that extended to 1 inch (2.4 cm) below the soil surface [102].
Although buffelgrass seeds can germinate throughout the year, germination is best with the onset of the wet season in spring and early summer. In a greenhouse experiment, Ward and others [135] found that the minimum amount of water needed to stimulate buffelgrass emergence was 0.25 inch (6.3 mm) or 0.12 inch (3.14 mm) on 2 consecutive days. Most buffelgrass seedlings emerged within the first 4 days following initial watering. Other herbaceous and woody perennial species in the Sonoran Desert require more moisture, a minimum of 0.68 to 1.4 inches (17.5 to 35.6 mm) of precipitation, for emergence [135].
In the laboratory, buffelgrass germination declined as moisture tension increased [104]. At approximately 0 MPa, buffelgrass germination was 100% after 8 days at a constant temperature of 90 °F (30 °C). At approximately 0.1 MPa, buffelgrass germination rate decreased to 55%, declining further to 25% at 0.2 MPa, and further to nearly 0% at 0.81 MPa [104].
"Large" buffelgrass seeds germinate better than "small" seeds. In field and greenhouse experiments buffelgrass seed size significantly affected the rate of germination (P<0.05) [76]. Seeds were divided into 3 size classes, then planted in field plots or greenhouse pots.
Buffelgrass germination rates by size class [76] |
||
Seed size | Seed weight (g) | Germination rate (%) |
Large | >0.0700 | 56.3 |
Medium | 0.0401-0.0699 | 46.8 |
Small | <0.0400 | 39.3 |
A laboratory study indicated that buffelgrass seed germination decreased with decreasing pH [112]. After 12 days, buffelgrass germination was ~65% at pH 7.0, ~55% at pH 4.0, and 0% at pH 1.0 [112].
Seedling establishment/growth: Buffelgrass seedlings may establish at any time of year, but establishment is greatest at the onset of the wet season [126]. Once established, buffelgrass seedling growth rate is "fast" [25]. Clay soils may support the most rapid seedling growth. Thirty days after emergence, buffelgrass seedling culm length and seedling oven-dry weight were 6.14 inches (15.6 cm) and 0.00327 ounce (92.7 mg) in clay, 3.1 inches (7.8 cm) and 0.00322 ounce (91.3 mg) in sandy clay loam, and 2.8 inches (7.2 cm) and 0.0022 ounce (62.4 mg) in sandy loam [102].
Seed size did not affect buffelgrass seedling survival but was positively associated with seedling height and weight after 60 days. Buffelgrass seedling survival was significantly better in the greenhouse (98%) than in the field (85%), but seedling height and weight were significantly greater in the field, likely due to increased light availability [76].
The effect of seed size and growing site on buffelgrass height and total weight after 60 days [76] |
||||
Seed size | Growing site | |||
Greenhouse |
Field | |||
Height (cm) | Total oven-dried weight (g) | Height (cm) | Total oven-dried weight (g) | |
Small | 6.1b* | 0.04b | 7.9b | 0.05c |
Medium | 7.4a | 0.09a | 9.4a | 0.12b |
Large | 7.9a | 0.10a | 10.0a | 0.15a |
*Values in columns with a different letter are significantly different (P<0.05) |
Buffelgrass seedlings can tolerate temperatures as low as 21 °F (-6.0 °C) [119].
Vegetative regeneration: Buffelgrass vegetative regeneration varies depending upon the strain or cultivar type. Several authors note that buffelgrass may have rhizomes [38,48,71,121,131], and at least 2 cultivars, 'Nueces' and 'Llano', are known to regenerate from rhizomes [110]. Buffelgrass forms with tillers are also described [75,113,122]. Duke [38] and Hickman [71] describe buffelgrass forms that reproduce via stolons.
6.1.2 Ecológico
Causa incendios en comunidades desérticas, con lo que las especies nativas se ven desplazadas. Posteriormente a un incendio es capaz de rebrotar rápidamente, compitiendo o reemplazando a especies nativas. La modificación de su hábitat afecta profundamente a ciertos animales nativos como algunas aves, lagartijas, serpientes, tortugas y roedores. Se considera como un zacate fuertemente invasor que limita el establecimiento de las especies nativas en el desierto sonorense (Chambers &Hawkins, 2004).
6.1.3 Económico
Produce de 1 a 6 ton /ha/año de materia seca, rebrotando en cualquier época del año, siempre y cuando exista humedad ó caiga lluvia (Villegas et al., 1998).
License | http://creativecommons.org/licenses/by-nc-sa/2.5/ |
Rights holder/Author | CONABIO |
Source | No source database. |
Isotype for Pennisetum rangei Mez
Catalog Number: US 101845
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Status verified by specimen annotations only
Preparation: Pressed specimen
Collector(s): P. Range
Locality: Namaland, SW Africa., Namibia, Africa
- Isotype: Mez, C. C. 1921. Bot. Jahrb. Syst. 57: 190.
License | http://creativecommons.org/licenses/by/3.0/ |
Rights holder/Author | This image was obtained from the Smithsonian Institution. Unless otherwise noted, this image or its contents may be protected by international copyright laws. |
Source | http://collections.mnh.si.edu/search/botany/?irn=11246644 |
More info on this topic.
More info for the term: hemicryptophyte
RAUNKIAER [107] LIFE FORM:
Hemicryptophyte
Cenchrus ciliaris (buffelgrass or African foxtail grass; syn. Pennisetum ciliare (L.) Link) is a species of grass native to most of Africa, southern Asia (east to India), southern Iran, and the extreme south of Europe (Sicily).[1]
It is a perennial grass growing to 50 cm tall. The leaves are linear, 3–25 cm long and 4–10 mm wide. The flowers are produced in a panicle 2–14 cm long and 1–2.6 cm wide.[2]
As an invasive species[edit]
Cenchrus ciliaris has become naturalised and often an invasive species in Australia, the southwestern United States, Hawaii, Mexico, Central America, South America, and Macaronesia.[1] In the Sonoran Desert it was introduced for erosion control. In the Mexican part of the Sonoran Desert, it is still being planted and irrigated for livestock grazing.
It spreads very quickly and will often kill local native plants such as palo verdes by taking away nearby water. This plant has a very low ignition threshold and can burst into a raging flame even during the peak growing season. Its flammability and quick regrowth allow it to compete successfully against almost all vegetation in this region.[3]
References[edit]
- ^ a b Germplasm Resources Information Network: Cenchrus ciliaris.
- ^ Clayton, W.D., Harman, K.T. and Williamson, H. (2006 onwards). "Cenchrus ciliaris". GrassBase - The Online World Grass Flora. Royal Botanic Gardens, Kew. Check date values in:
|date=
(help) - ^ Arizona-Sonora Desert Museum: Buffelgrass.
4. Volunteer opportunities. (2013). Southern Arizona Buffelgrass Coordination Center. Retrieved from http://www.buffelgrass.org/voluteeropportunities
License | http://creativecommons.org/licenses/by-sa/3.0/ |
Rights holder/Author | Wikipedia |
Source | http://en.wikipedia.org/w/index.php?title=Cenchrus_ciliaris&oldid=599571237 |
More info for the term: warm-season
Buffelgrass occurs on disturbed [17,56,140,141] and undisturbed [17,43] sites, on rangelands [56], in deserts [17,50], along roads and highways [4,18,19,24,43,47,50,68], on lowlands [25], uplands [25,121], in city lots [50], on slopes, rocky sites [93], and in riparian areas [43].
Climate and precipitation: Buffelgrass is adapted to arid and semiarid climates [5,17,66,69]. It is frost-susceptible [66,99,121], and drought-tolerant [10,50]. In its native habitat, climates are subhumid to arid with predominantly warm-season rainfall, so buffelgrass is well adapted to the soil moisture regimes typical of southern Arizona [30]. Where buffelgrass dominates and has expanded its range in North America, annual rainfall varies from 8 to 49 inches (200 mm-1,250 mm) and temperatures rarely drop below 40 °F (5 °C) [26,30,78]. The rhizomatous cultivars 'Nueces' and 'Llano' are better suited for colder climates [110,131].
Elevation: Buffelgrass occurs from 20 to 2,700 feet (6-830 m) in North America [30]. It occurs from sea level to 400 feet (0-120 m) in Hawaii (review by [87]). Freezing temperatures above 3,000 feet (900 m) and at high latitudes impede buffelgrass spread [125].
Soil: Buffelgrass occurs on a range of soil textures but is most common on sandy soils [26,30]. In Texas, buffelgrass is common on sandy soils throughout the South Plains [56]. Hanselka [66] states that buffelgrass grows readily on the sandy loam soils that are widespread throughout southern Texas. Buffelgrass seeds germinate and emerge in sandy, silty, and clayey soils. Cox and others [26,30] note that buffelgrass seedling emergence declines as sand, silt, or clay content approaches 100%. Buffelgrass growth is severely inhibited on highly saline soils, deep sands, tight clays, and soils with poor surface drainage [66]. In Mexico, buffelgrass survival and spread were negatively associated with total soil organic matter [29].
Sites in Kenya, where buffelgrass is native, and sites in Texas and Mexico, where buffelgrass has been planted, were studied to identify soil characteristics best suited for buffelgrass cultivation [28,78]. Site elevations in Texas and Mexico ranged from 70 to 2,000 feet (20-700 m); in Kenya, they ranged from 50 to 1,900 feet (15-580 m). Annual precipitation ranged from 8 to 47 inches (200-1,200 mm) on study sites in Texas and Mexico and from 8 to 16 inches (200-400 mm) on study sites in Kenya. Study sites were classified according to whether buffelgrass spread (survived in the seeded area and established naturally from seed outside the seeded area), persisted (survived in the seeded area but did not establish outside the seeded area), or died (persisted in the seeded area for 10 or more years, but all plants eventually died). Buffelgrass is favored on sites where soils have a large percentage of sand, a low percentage of organic matter, and associated low cation exchange capacity [28,78].
Mean (SD) characteristics of the top 10 cm of soil where buffelgrass spread, persisted, or died in Texas, Mexico, and Kenya [28,78] | |||
Soil properties | Survival regime | ||
Spread | Persisted | Died | |
Sand (%) | 61.1 (20.2) | 44.9 (24.6) | 35.3 (15.4) |
Silt (%) | 17.5 (10.8) | 24.1 (13.2) | 32.3 (7.2) |
Clay (%) | 21.5 (11.6) | 31.0 (15.3) | 32.4 (11.2) |
Silt + clay (%) | 39.0 (18.7) | 55.1 (24.3) | 64.7 (16.2) |
pH | 7.8 (0.5) | 7.6 (0.6) | 7.5 (0.4) |
Total nitrogen (%) | 0.1 (0.1) | 0.3 (0.2) | 0.5 (0.3) |
Organic carbon (%) | 0.9 (0.7) | 2.6 (2.9) | 4.4 (3.6) |
Phosphorus (mg/kg) | 10.6 (11.9) | 12.9 (12.7) | 10.0 (22.3) |
Cation exchange capacity (cmol/kg) | 22.5 (13.4) | 38.1 (24.4) | 61.8 (24.9) |
Sodium (cmol/kg) | 0.4 (0.6) | 0.4 (0.4) | 0.4 (0.2) |
Potassium (cmol/kg) | 1.1 (0.7) | 1.9 (1.3) | 1.8 (0.9) |
Calcium (cmol/kg) | 35.9 (26.5) | 42.0 (23.0) | 47.8 (16.6) |
Magnesium (cmol/kg) | 1.9 (1.5) | 3.2 (2.2) | 3.7 (2.5) |
Soils in areas converted from desert scrub to buffelgrass pastures in Sonora differ from those in unconverted sites [18,78]. Soil under buffelgrass has higher organic matter content and is exposed to higher insolation than soil under native vegetation [78]. Burquez and others [18] suggest that soil nutrients are depleted in buffelgrass pastures by the net export of nutrients taken by cattle and the volatilization of nitrogen, phosphorus, and potassium during recurrent fires.