Crypsis vaginiflora (African pricklegrass)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Hosts/Species Affected
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Rainfall Regime
- Soil Tolerances
- Means of Movement and Dispersal
- Pathway Causes
- Impact Summary
- Environmental Impact
- Threatened Species
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- Gaps in Knowledge/Research Needs
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Crypsis vaginiflora (Forssk.) Opiz
Preferred Common Name
- African pricklegrass
Other Scientific Names
- Crypsis compacta Steud.
- Crypsis niliaca Fig. & De Not.
- Heleochloa compacta (Steud.) T.Durand & Schinz
- Phalaris vaginiflora Forssk.
International Common Names
- English: African prickle grass; modest prickegrass; modest prickle grass
Summary of InvasivenessTop of page
C. vaginiflora is an annual grass, with a native distribution ranging from northern and eastern Africa to the Middle East and India. It is known to be introduced to the USA and Mexico, but is thought to only be invasive in California, where it is common in vernal pools and wetlands. As a mat-forming species it is thought to impact negatively on native flora, although such impacts have not been documented. C. vaginiflora has also naturalized in Baja California, Mexico.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Monocotyledonae
- Order: Cyperales
- Family: Poaceae
- Genus: Crypsis
- Species: Crypsis vaginiflora
Notes on Taxonomy and NomenclatureTop of page
The ten species in the genus Crypsis (Aiton) are native to the Old World, mostly in Eurasia and Africa (Peterson et al., 2014; eMonocot, 2015). Species in this genus are typically annuals and have short panicles that are often surrounded by the leaf sheath (Peterson et al., 2014). Crypsis is derived from the Greek kryptos, meaning hidden, and refers to the inflorescences that are contained within the uppermost leaf sheaths (Simon and Alfonso, 2011). C. vaginiflora was historically considered synonymous with C. schoenoides, but is now recognized as a separate species (Hammel and Reeder, 1979). Recently, Peterson et al. (2014) recommended subsuming Crypsis into the genus Sporobolus, which would mean C. vaginiflora would become Sporobolus niliacus.
DescriptionTop of page
Following Hammel and Reeder (1979) and eMonocot (2015):
C. vaginiflora is an annual grass that forms mats or short clumps and is most easily identified by the small, dense panicles (up to 1.5 cm long) that are embedded in the sheaths of the large, highest leaves. This species’ culms are generally decumbent, between 1 and 30 cm long, and are repeatedly branched. Leaf sheaths and collars are generally hairy. Leaf blades are stiff, glaucous and often shed at the ligule, but when present are between 1 and 5 cm long and 2 to 3 mm wide. Inflorescences are dense panicles, 0.3 to 1.5 cm long, 0.3 to 0.6 cm wide, ovoid in shape, and embraced by large leaf sheaths. Spikelets are elliptic in shape, laterally compressed, and 2.5 to 3.2 mm long. Upper and lower glumes are of similar length (2.5 – 3.2 mm long), and tend to be pilose along their margins. There are three anthers between 0.6 and 0.7 mm long. Seeds are between 1.3 and 1.7 mm long, 0.6 to 0.9 mm wide and dark brown in colour.
Plant TypeTop of page
Grass / sedge
DistributionTop of page
According to eMonocot (2015), C. vaginiflora is native to northern and eastern Africa and has a distribution extending through the Middle East to India. The GRIN (USDA-ARS, 2015) distribution however, includes fewer countries, with no records in the Middle East and only five African countries listed (Egypt, Ethiopia, Sudan, Tanzania, Senegal) and India.
The only records of this species being introduced come from the USA (California, Idaho, Nevada, Oregon and Washington states) and Mexico (Baja California) (Randall, 2012; eMonocot, 2015).
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.Last updated: 10 Jan 2020
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Mexico||Present||Introduced||Earliest record in 1980|
|United States||Present||Present based on regional distribution.|
|-California||Present, Widespread||Introduced||Invasive||Earliest record in 1906|
|-Idaho||Present, Few occurrences||Introduced||Only record is from Gooding county in 1976|
|-Nevada||Present||Introduced||Earliest record in 1998|
|-Oregon||Present||Introduced||Earliest record in 1978|
History of Introduction and SpreadTop of page
Hammel and Reeder (1979) suggest that the first published records for C. vaginiflora in the USA date back to 1912. Herbarium records place the earliest record in the USA in 1906, in Inglewood, Los Angeles, California (GBIF, 2015). The earliest herbarium records for other states are 1976 in Idaho, 1978 in Oregon, and 1998 in Nevada (GBIF, 2015). There are no records, however, that indicate how C. vaginiflora was introduced. However, C. vaginiflora is eaten by waterfowl such as the northern pintail in California (Fleskes et al., 2005), and it is possible these birds have aided its spread.
Risk of IntroductionTop of page
C. vaginiflora is eaten by waterfowl such as the northern pintail in California (Fleskes et al., 2005). As these birds are migratory there is a risk that new introductions may occur if populations transit from a site containing C. vaginiflora to one which does not. It is also possible, due to the small seed size of this plant, that seeds may be accidentally introduced as contaminant in imported pasture seed.
HabitatTop of page
Habitat ListTop of page
|Terrestrial||Natural / Semi-natural||Riverbanks||Present, no further details|
|Terrestrial||Natural / Semi-natural||Wetlands||Present, no further details|
Hosts/Species AffectedTop of page
Biology and EcologyTop of page
C. vaginiflora has a chromosome number of 2n = 48, compared to C. schoenoides, which has a chromosome number of 2n = 32 (Hammel and Reeder, 1979; IPCN Chromosome Reports, 2015). It has been suggested that the genus Crypsis be incorporated into Sporobolus, because of its embedded position in a paraphyletic Sporobolus clade (Peterson et al., 2014).
As for most grasses, C. vaginiflora is wind pollinated and has bisexual flowers. C. vaginiflora has small, dark brown seeds between 0.5 and 1.5 mm long. Seeds have an average 1000 seed weight of 0.568 g (Hammel and Reeder, 1979; eMonocot, 2015; Royal Botanic Gardens Kew, 2015).
Physiology and Phenology
This species is an annual, although smaller individuals sometimes survive through dry winters (Hammel and Reeder, 1979).
C. vaginiflora uses the C4 photosynthetic pathway (Osborne et al., 2014). In California, this species flowers from June to September (Calflora, 2015), although perhaps from as early as May (Hammel and Reeder, 1979).
C. vaginiflora prefers clay or sandy clay soils, often at the edges of drying lakes or in vernal pools (Hammel and Reeder, 1979). Climate preferences and tolerances are based on overlaying distribution records of this species on a global map of of Köppen-Geiger climate zones (Kriticos et al., 2011) and global temperature and precipitation layers (Hijmans et al., 2005).
ClimateTop of page
|BS - Steppe climate||Preferred||> 430mm and < 860mm annual precipitation|
|BW - Desert climate||Tolerated||< 430mm annual precipitation|
|Cf - Warm temperate climate, wet all year||Tolerated||Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year|
|Cs - Warm temperate climate with dry summer||Preferred||Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers|
|Ds - Continental climate with dry summer||Preferred||Continental climate with dry summer (Warm average temp. > 10°C, coldest month < 0°C, dry summers)|
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Air TemperatureTop of page
|Parameter||Lower limit||Upper limit|
|Mean annual temperature (ºC)||6.4||18|
|Mean maximum temperature of hottest month (ºC)||20.3||36.5|
|Mean minimum temperature of coldest month (ºC)||-10.1||9.1|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Mean annual rainfall||146||1800||mm; lower/upper limits|
Rainfall RegimeTop of page
Soil TolerancesTop of page
- seasonally waterlogged
Means of Movement and DispersalTop of page
The seeds of C. vaginiflora are likely to be dispersed by wind (Thomson et al., 2010).
Vector Transmission (Biotic)
C. vaginiflora is a source of forage for waterfowl such as northern pintail in California, and its seeds may be spread by these birds (Fleskes et al., 2005).
It is not known how this species was introduced into North America. It is possible and quite likely to have arrived as a contaminant, possibly in imported pasture seed, given the small size of its seeds.
Pathway CausesTop of page
Impact SummaryTop of page
|Environment (generally)||Positive and negative|
Environmental ImpactTop of page
This species has only been reported as invasive in California, and here only in wetlands (Hammel and Reeder, 1979). It is perhaps not as abundant as its sister species, C. schoenoides, but likely has similar impacts. Both species are used as forage by waterfowl (e.g. pintail, Anas acuta) and have positive impacts on these birds (Naylor, 1999; Fleskes et al., 2005; Rahilly et al., 2012). However, where C. vaginiflora is highly abundant, it is likely to have negative impacts on other wetland plant species and other aspects of biodiversity through competitive exclusion.
Threatened SpeciesTop of page
Risk and Impact FactorsTop of page
- Proved invasive outside its native range
- Has a broad native range
- Fast growing
- Has propagules that can remain viable for more than one year
- Monoculture formation
- Competition - strangling
- Competition (unspecified)
- Highly likely to be transported internationally accidentally
- Difficult to identify/detect as a commodity contaminant
- Difficult to identify/detect in the field
UsesTop of page
Economic Value and Social Benefit
C. vaginiflora has indirect economic and social benefits by providing forage for waterfowl, which are popular for hunting purposes (Fleskes et al., 2005).
Uses ListTop of page
Animal feed, fodder, forage
- Wildlife habitat
Similarities to Other Species/ConditionsTop of page
C. vaginiflora is very similar to C. schoenoides and was for a long time considered to be the same species (Hammel and Reeder, 1979). C. vaginiflora is distinguished from C. schoenoides by generally lacking pink-tinged stems and spikelets, being shorter (culms up to 30 cm compared to 75 cm), having repeatedly-branching culms, smaller panicles (up to 1.5 cm compared to 3 cm), shorter leaf blades (up to 5 cm compared to 12 cm), shorter anthers (up to 0.7 mm compared to 0.9 mm), and disarticulating leaf blades (Hammel and Reeder, 1979; eMonocot, 2015).
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
There appears to be no specific literature for the control of C. vaginiflora. Physical control methods such as hand pulling (especially in the early stages of an invasion) and covering with black plastic have been successfully used to control other wetland grasses such as Phalaris arundinacea and Spartina species (ISSG, 2015). Chemical control might be possible using imazapyr, because it has been successfully used on other wetland invasives (Tu et al., 2001; ISSG, 2015).
Gaps in Knowledge/Research NeedsTop of page
More research is needed about the biogeography, dispersal and impacts of C. vaginiflora. It would be useful to determine whether this species is invasive in regions other than California. Little is known about how this species has spread outside of its native range, and it would be useful to confirm whether waterfowl are indeed dispersing the seeds of this species locally. Almost nothing is known about how this species impacts native biodiversity.
ReferencesTop of page
Calflora, 2016. Information on California plants for education, research, and conservation. Berkeley, California, USA: Calflora Database. http://www.calflora.org
eMonocot, 2015. eMonocot - An online resource for monocot plants. http://emonocot.org/
Fleskes JP, Gilmer DS, Jarvis RL, 2005. Pintail distribution and selection of marsh types at Mendota Wildlife Area during fall and winter. California Fish and Game, 91(4):270-285.
Flora Zambesiaca, 2015. Flora Zambesiaca online (eFloras). Richmond, Surrey, UK: Kew Databases. http://apps.kew.org/efloras/search.do
GBIF, 2015. Global Biodiversity Information Facility. http://www.gbif.org/species
Hammel BE, Reeder JR, 1979. The genus Crypsis (Gramineae) in the United States. Systematic Botany, 4(4):267-280.
IPCN Chromosome Reports, 2015. Index to Plant Chromosome Numbers (IPCN), Tropicos website. St. Louis, Missouri, USA: Missouri Botanical Garden. http://tropicos.org/Project/IPCN
ISSG, 2015. Global Invasive Species Database (GISD). Invasive Species Specialist Group of the IUCN Species Survival Commission. http://www.issg.org/database/welcome/
Keeley JE, Zedler PH, 1998. Characterization and global distribution of vernal pools. In: Ecology, conservation, and management of vernal pool ecosystems conference: Proceedings from 1996 conference [ed. by Witham CW, Bauder ET, Belk D, Ferren Jr WR, Ornduff R. Sacramento, California, USA: California Native Plant Society, 1-14.
Kriticos DJ, Webber BL, Leriche A, Ota N, Macdam I, Bathols J, Scott JK, 2011. CliMond: global high resolution historical and future scenario climate surfaces for bioclimatic modelling. Methods in Ecology and Evolution, 3:53-64.
Missouri Botanical Garden, 2015. Tropicos database. St. Louis, Missouri, USA: Missouri Botanical Garden. http://www.tropicos.org/
NatureServe, 2015. NatureServe Explorer: An online encyclopedia of life (Version 7.1). Arlington, Virginia, USA: NatureServe. http://explorer.natureserve.org
Naylor LM, 1999. Evaluating moist-soil seed production and management in Central Valley wetlands to determine habitat needs for waterfowl. Masters Thesis. Davis, California, USA: University of California.
Osborne CP, Salomaa A, Kluyver TA, Visser V, Kellogg EA, Morrone O, Vorontsova MS, Clayton WD, Simpson DA, 2014. A global database of C4 photosynthesis in grasses. New Phytologist, 204(3):441-446.
Rahilly P, Li DH, Guo QH, Zhu JX, Ortega R, Quinn NWT, Harmon TC, 2012. Mapping swamp timothy (Crypsis schoenoides) seed productivity using spectral values and vegetation indices in managed wetlands. International Journal of Remote Sensing, 33(16):4902-4918.
Randall RP, 2012. A global compendium of weeds (2nd edn). Western Australia: Department of Agriculture and Food Western Australia, 1124 pp.
Royal Botanic Gardens Kew, 2015. Seed Information Database (SID) Version 7. Richmond, Surrey, UK: Royal Botanic Gardens Kew. http://data.kew.org/sid/
Simon BK, Alfonso Y, 2011. AusGrass2. Grasses of Australia. Australia: CSIRO Publishing. http://ausgrass2.myspecies.info/
Tu M, Hurd C, Randall JM, 2001. Weed Control Methods Handbook (April 2001 edition). Arlington, Virginia, USA: The Nature Conservancy. http://www.invasive.org/gist/products/handbook/methods-handbook.pdf
USDA-ARS, 2015. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
USDA-NRCS, 2015. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/
CABI, Undated. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
eMonocot, 2015. eMonocot - an online resource for monocot plants.,
Flora Zambesiaca, 2015. Flora Zambesiaca online (eFloras)., Richmond, Surrey, UK: Kew Databases. http://apps.kew.org/efloras/search.do
GBIF, 2015. Global Biodiversity Information Facility. http://www.gbif.org/species
Hammel BE, Reeder JR, 1979. The genus Crypsis (Gramineae) in the United States. In: Systematic Botany, 4 (4) 267-280.
Missouri Botanical Garden, 2015. Tropicos database., St. Louis, Missouri, USA: Missouri Botanical Garden. http://www.tropicos.org/
USDA-ARS, 2015. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx
USDA-NRCS, 2015. The PLANTS Database. Greensboro, North Carolina, USA: National Plant Data Team. https://plants.sc.egov.usda.gov
ContributorsTop of page
27/03/15 Original text by:
Vernon Visser, Centre for Invasion Biology, Stellenbosch University, South Africa
Distribution MapsTop of page
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