Crypsis vaginiflora
(African pricklegrass)

Pictures

Picture	Title	Caption	Copyright
Title Habit Caption Crypsis vaginiflora (African pricklegrass), habit in a grassland depression. East of highway 113, Solano County, California, USA. August, 2010. Copyright ©Zoya Akulova-2010/CalPhotos - CC BY-NC 3.0	Habit	Crypsis vaginiflora (African pricklegrass), habit in a grassland depression. East of highway 113, Solano County, California, USA. August, 2010.	©Zoya Akulova-2010/CalPhotos - CC BY-NC 3.0
Title Habit Caption Crypsis vaginiflora (African pricklegrass), habit in a seasonal wetland. North-east Fairfield, Vanden Rd., Solano County, California, USA. July, 2010. Copyright ©Zoya Akulova-2010/CalPhotos - CC BY-NC 3.0	Habit	Crypsis vaginiflora (African pricklegrass), habit in a seasonal wetland. North-east Fairfield, Vanden Rd., Solano County, California, USA. July, 2010.	©Zoya Akulova-2010/CalPhotos - CC BY-NC 3.0
Title Habit Caption Crypsis vaginiflora (African pricklegrass), habit in a seasonal wetland. North-east Fairfield, Vanden Rd., Solano County, California, USA. July, 2010. Copyright ©Zoya Akulova-2010/CalPhotos - CC BY-NC 3.0	Habit	Crypsis vaginiflora (African pricklegrass), habit in a seasonal wetland. North-east Fairfield, Vanden Rd., Solano County, California, USA. July, 2010.	©Zoya Akulova-2010/CalPhotos - CC BY-NC 3.0

Identity

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 Invasiveness

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 Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Monocotyledonae
•                     Order: Cyperales
•                         Family: Poaceae
•                             Genus: Crypsis
•                                 Species: Crypsis vaginiflora

Notes on Taxonomy and Nomenclature

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.

Description

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 Type

Distribution

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 Table

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.

History of Introduction and Spread

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 Introduction

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.

Habitat

C. vaginiflora almost always grows in wetlands, vernal pools or similar waterbodies (Hammel and Reeder, 1979; Calflora, 2015; NatureServe, 2015; USDA-NRCS, 2015).

Habitat List

Hosts/Species Affected

C. vaginiflora appears to be invasive in Californian wetlands (Hammel and Reeder, 1979; Fleskes et al., 2005) and is thought to impact on other wetland plants in this region.

Biology and Ecology

Genetics

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).

Reproductive Biology

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).

Environmental Requirements

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).

Climate

Latitude/Altitude Ranges

Air Temperature

Rainfall

Rainfall Regime

Soil Tolerances

Soil drainage

• impeded
• seasonally waterlogged

Soil texture

• heavy
• light
• medium

Means of Movement and Dispersal

Natural Dispersal

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).

Accidental Introduction

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 Causes

Impact Summary

Environmental Impact

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 Species

Risk and Impact Factors

• 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

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect as a commodity contaminant
• Difficult to identify/detect in the field

Uses

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 List

Animal feed, fodder, forage

• Forage

Environmental

• Wildlife habitat

Similarities to Other Species/Conditions

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 Control

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 Needs

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.

References

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.

Hijmans RJ, Cameron SE, Parra JL, Jones PG, Jarvis A, 2005. Very high resolution interpolated climate surfaces for global land areas. International Journal of Climatology, 25(15):1965-1978.

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.

Peterson PM, Romaschenko K, Arrieta YH, Saarela JM, 2014. A molecular phylogeny and new subgeneric classification of Sporobolus (Poaceae: Chloridoideae: Sporobolinae). Taxon, 63(6):1212-1243.

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/

Thomson FJ, Moles AT, Auld TD, Ramp D, Ren ShiQuan, Kingsford RT, 2010. Chasing the unknown: predicting seed dispersal mechanisms from plant traits. Journal of Ecology (Oxford), 98(6):1310-1318.

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

US Fish and Wildlife Service, 2009. In: Hairy Orcutt Grass (Orcuttia pilosa). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 26 pp.

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/

Contributors

27/03/15 Original text by:

Vernon Visser, Centre for Invasion Biology, Stellenbosch University, South Africa

Distribution Maps