Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Crypsis schoenoides
(swamp pricklegrass)

Toolbox

Datasheet

Crypsis schoenoides (swamp pricklegrass)

Summary

  • Last modified
  • 06 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Crypsis schoenoides
  • Preferred Common Name
  • swamp pricklegrass
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Monocotyledonae
  • Summary of Invasiveness
  • C. schoenoides is an annual grass, with a native distribution ranging from southern Europe and North Africa, across Middle East, to northern India and China. It has been introduced into North America, Australia...

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Pictures

Top of page
PictureTitleCaptionCopyright
Crypsis schoenoides (swamp pricklegrass); flowering habit. Close view of flower head. 
West Sacramento, California, USA. July, 2015.
TitleFlowering habit
CaptionCrypsis schoenoides (swamp pricklegrass); flowering habit. Close view of flower head. West Sacramento, California, USA. July, 2015.
Copyright©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); flowering habit. Close view of flower head. 
West Sacramento, California, USA. July, 2015.
Flowering habitCrypsis schoenoides (swamp pricklegrass); flowering habit. Close view of flower head. West Sacramento, California, USA. July, 2015.©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
TitleHabit
CaptionCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.
Copyright©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
HabitCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
TitleHabit
CaptionCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.
Copyright©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
HabitCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
TitleHabit
CaptionCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.
Copyright©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
HabitCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
TitleHabit
CaptionCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.
Copyright©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). 
West Sacramento, California, USA. July, 2015.
HabitCrypsis schoenoides (swamp pricklegrass); habit. C. schoenoides is common as ground cover in dried up wetlands. The grass is bunched, but spreading and the dense stands form a matted habit. The taller dispersed plant is Xanthium strumarium (rough cocklebur). West Sacramento, California, USA. July, 2015.©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); stems and ligules. 
West Sacramento, California, USA. July, 2015.
TitleStems
CaptionCrypsis schoenoides (swamp pricklegrass); stems and ligules. West Sacramento, California, USA. July, 2015.
Copyright©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Crypsis schoenoides (swamp pricklegrass); stems and ligules. 
West Sacramento, California, USA. July, 2015.
StemsCrypsis schoenoides (swamp pricklegrass); stems and ligules. West Sacramento, California, USA. July, 2015.©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0

Identity

Top of page

Preferred Scientific Name

  • Crypsis schoenoides

Preferred Common Name

  • swamp pricklegrass

Other Scientific Names

  • Heleochloa schoenoides (L.) Host
  • Pechea subcylindrica Pourr. ex Kunth
  • Phleum schoenoides L.
  • Phleum supinum Lam.
  • Spartina phleoides (L.) Roth
  • Spartina schoenoides (L.) Roth

International Common Names

  • English: cowpond grass; swamp Timothy
  • French: crypside faux choin; crypsis faux choin
  • Chinese: lin zhuang yin hua cao

Local Common Names

  • Italy: brignolo ovato
  • Sweden: tittutgräs

Summary of Invasiveness

Top of page

C. schoenoides is an annual grass, with a native distribution ranging from southern Europe and North Africa, across Middle East, to northern India and China. It has been introduced into North America, Australia, Madagascar and Japan, where it has naturalized. However, it is only considered to be a major invader in California, where it is very abundant in wetlands and other waterbodies. Its dominance in these habitats, where it forms dense mats, means it is likely to have negative impacts on plant biodiversity in Californian wetlands.

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Monocotyledonae
  •                     Order: Cyperales
  •                         Family: Poaceae
  •                             Genus: Crypsis
  •                                 Species: Crypsis schoenoides

Notes on Taxonomy and Nomenclature

Top of page

There are ten species in the genus Crypsis (Aiton), all of which are endemic to the Old World (Eurasia and Africa) (Peterson et al., 2014). 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.

Description

Top of page

Following Hammel and Reeder (1979) and eMonocot (2015):

C. schoenoides is most easily identified by its pink- or purple-tinged stems and spikelets and its tendency to form mats or short clumps. It is an annual, tufted grass with culms that can be prostrate or erect, up to 75 cm tall, and sometimes much-branched from the base. Leaf blades are 0.5-12 cm long, 0.1-0.4 cm wide, mostly flat and the upper surfaces are often hairier than the lower leaf blade surfaces, although both may be glabrous. Inflorescences are compound, much-branched, ellipsoid or ovoid in shape, up to 3 cm long, and often are surrounded at the base by the enlarged leaf sheath. Spikelets are laterally compressed, up to 4 mm long and green to purple in colour. Upper and lower glumes are similar, up to 4 mm long and 1-nerved. Palea 2-nerved, slightly shorter or equal in length to lemma (up to 4 mm), which is 1-nerved. Three anthers up to 0.9 mm long. Caryopsis is 0.5-1.5 mm long.

Distribution

Top of page

The native distribution of C. schoenoides encompasses a large range including Mediterranean Europe, the Balkans and south-eastern Europe, North Africa, the Middle East and extending through Asia to northern India and parts of China (eMonocot, 2015; USDA-ARS, 2015). It is also recorded as native to the eastern and southern African countries of Mozambique, Malawi and Tanzania (eMonocot, 2015; USDA-ARS, 2015).

C. schoenoides is considered as not native at the limits of its current continuous range (i.e. across Africa, Europe and Asia). For example, in parts of northern Europe (such as Belgium, the Netherlands and the United Kingdom) and in West Africa (Mali and Mauritania) it is considered to be introduced. There is also uncertainty as to the native status of this species in Senegal and Madagascar, with the USDA-ARS (2015) recording it as native in these two regions, but with eMonocot (2015) recording it as an introduced species. 

C. schoenoides has been introduced into North America, Australia, Madagascar and Japan (eMonocot, 2015; USDA-ARS, 2015).

Distribution Table

Top 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.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

AfghanistanPresentNativeeMonocot, 2015; USDA-ARS, 2015
ArmeniaPresentNativeeMonocot, 2015; USDA-ARS, 2015
AzerbaijanPresentNativeeMonocot, 2015; USDA-ARS, 2015
ChinaPresentNativeRandall, 2012
-AnhuiPresentNativeMissouri Botanical Garden, 2015
-HebeiPresentNativeMissouri Botanical Garden, 2015; USDA-ARS, 2015
-HenanPresentNativeMissouri Botanical Garden, 2015
-JiangsuPresentNativeMissouri Botanical Garden, 2015; USDA-ARS, 2015
-Nei MengguPresentNativeMissouri Botanical Garden, 2015; USDA-ARS, 2015
-NingxiaPresentNativeMissouri Botanical Garden, 2015
-ShanxiPresentNativeMissouri Botanical Garden, 2015
-XinjiangPresentNativeMissouri Botanical Garden, 2015; USDA-ARS, 2015
Georgia (Republic of)PresentNativeeMonocot, 2015; USDA-ARS, 2015
IndiaPresentPresent based on regional distribution.
-Himachal PradeshPresentNativeeMonocot, 2015
-Indian PunjabNativeMissouri Botanical Garden, 2015
-Jammu and KashmirPresentNativeeMonocot, 2015
-UttarakhandPresentNativeeMonocot, 2015
IranPresentNativeeMonocot, 2015; USDA-ARS, 2015
IraqPresentNativeeMonocot, 2015
IsraelPresentNativeeMonocot, 2015; USDA-ARS, 2015
JapanPresentIntroduced Not invasive Koba and Tanaka, 2000; Randall, 2012; GBIF, 2015Earliest record in 1998
JordanPresentNativeUSDA-ARS, 2015
KazakhstanPresentNativeeMonocot, 2015; USDA-ARS, 2015
KyrgyzstanPresentNativeeMonocot, 2015
LebanonPresentNativeeMonocot, 2015; USDA-ARS, 2015
MongoliaPresentNativeeMonocot, 2015
PakistanPresentNativeeMonocot, 2015; Missouri Botanical Garden, 2015
SyriaPresentNativeeMonocot, 2015; USDA-ARS, 2015
TaiwanPresentIntroducedRandall, 2012
TajikistanPresentNativeeMonocot, 2015
TurkeyPresentNativeeMonocot, 2015; USDA-ARS, 2015
TurkmenistanPresentNativeeMonocot, 2015; USDA-ARS, 2015
UzbekistanPresentNativeeMonocot, 2015; USDA-ARS, 2015
YemenPresentNativeeMonocot, 2015

Africa

AlgeriaPresentNativeeMonocot, 2015; USDA-ARS, 2015
EgyptPresentNativeRandall, 2012; eMonocot, 2015; USDA-ARS, 2015
LibyaPresentNativeeMonocot, 2015; USDA-ARS, 2015
MadagascarPresenteMonocot, 2015; GBIF, 2015; USDA-ARS, 2015Earliest record in 1955
MalawiPresentNativeeMonocot, 2015; USDA-ARS, 2015
MaliPresentIntroducedeMonocot, 2015
MauritaniaPresentIntroducedeMonocot, 2015
MoroccoPresentNativeeMonocot, 2015; USDA-ARS, 2015
MozambiquePresentNativeeMonocot, 2015; USDA-ARS, 2015
NigerPresentNativeeMonocot, 2015
SenegalPresenteMonocot, 2015; USDA-ARS, 2015
SudanPresentNativeeMonocot, 2015; USDA-ARS, 2015
TanzaniaPresentNativeeMonocot, 2015; USDA-ARS, 2015
TunisiaPresentNativeeMonocot, 2015; USDA-ARS, 2015

North America

CanadaPresentPresent based on regional distribution.
-OntarioPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1977
MexicoPresentIntroducedeMonocot, 2015; GBIF, 2015; Missouri Botanical Garden, 2015Present in Baja California. Earliest record in 1979
USAPresentPresent based on regional distribution.
-ArizonaPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1979
-CaliforniaWidespreadIntroduced Invasive Hammel and Reeder, 1979; Randall, 2012; eMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1913
-IllinoisPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1893
-IndianaPresentIntroducedeMonocot, 2015; USDA-NRCS, 2015
-IowaPresentIntroducedUSDA-NRCS, 2015
-MassachusettsPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1908
-MichiganPresent, few occurrencesIntroduced Not invasive Reznicek et al., 2011; eMonocot, 2015; USDA-NRCS, 2015Earliest record in 1930. Only in Monroe and Wayne counties
-MissouriPresentIntroducedeMonocot, 2015; USDA-NRCS, 2015Earliest record in 1926
-NevadaPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1976
-New JerseyPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1895
-New YorkPresentIntroducedeMonocot, 2015; USDA-NRCS, 2015
-OhioPresentIntroducedeMonocot, 2015; USDA-NRCS, 2015
-OregonPresent, few occurrencesIntroduced Not invasive Hammel and Reeder, 1979; eMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1976
-PennsylvaniaPresentIntroducedeMonocot, 2015; USDA-NRCS, 2015Earliest record in 1866
-UtahPresent, few occurrencesIntroduced Not invasive Hammel and Reeder, 1979; eMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1973
-WisconsinPresentIntroducedeMonocot, 2015; GBIF, 2015; USDA-NRCS, 2015Earliest record in 1940

Europe

AlbaniaPresentNativeeMonocot, 2015; USDA-ARS, 2015
AustriaPresentNativeeMonocot, 2015; USDA-ARS, 2015
BelarusPresentNativeeMonocot, 2015
BelgiumPresentIntroduced Not invasive Verloove, 2006; Randall, 2012; DAISIE, 2015
Bosnia-HercegovinaPresentNativeeMonocot, 2015
BulgariaPresentNativeeMonocot, 2015; USDA-ARS, 2015
CroatiaPresentNativeeMonocot, 2015; USDA-ARS, 2015
CyprusPresentNativeeMonocot, 2015; USDA-ARS, 2015
Czech RepublicPresentNativeeMonocot, 2015; USDA-ARS, 2015
Czechoslovakia (former)PresentNativeeMonocot, 2015; USDA-ARS, 2015
FrancePresentNativeeMonocot, 2015; USDA-ARS, 2015
-CorsicaPresentRoyal Botanic Garden Edinburgh, 2015; Royal Botanic Garden Edinburgh, 2015
GreecePresentNativeeMonocot, 2015; USDA-ARS, 2015
-CretePresentRoyal Botanic Garden Edinburgh, 2015
HungaryPresentNativeeMonocot, 2015; USDA-ARS, 2015
ItalyPresentNativeeMonocot, 2015; USDA-ARS, 2015
-SardiniaPresentRoyal Botanic Garden Edinburgh, 2015
-SicilyPresentRoyal Botanic Garden Edinburgh, 2015
LatviaPresent, few occurrencesIntroduced Not invasive DAISIE, 2015; NOBANIS, 2015Earliest record in 1963
MoldovaPresentNativeUSDA-ARS, 2015
PortugalPresentNativeeMonocot, 2015; USDA-ARS, 2015
RomaniaPresentNativeeMonocot, 2015; USDA-ARS, 2015
Russian FederationPresentPresent based on regional distribution.
-Central RussiaPresentNativeeMonocot, 2015; USDA-ARS, 2015
-Northern RussiaPresentNativeeMonocot, 2015
-Southern RussiaPresentNativeeMonocot, 2015
-Western SiberiaPresentNativeeMonocot, 2015; USDA-ARS, 2015
SerbiaPresentNativeeMonocot, 2015; USDA-ARS, 2015
SlovakiaPresentNativeeMonocot, 2015; USDA-ARS, 2015
SloveniaPresentNativeeMonocot, 2015
SpainPresentNativeeMonocot, 2015; USDA-ARS, 2015
UKPresentIntroducedRandall, 2012
UkrainePresentNativeeMonocot, 2015; USDA-ARS, 2015
Yugoslavia (former)PresentRoyal Botanic Garden Edinburgh, 2015

Oceania

AustraliaPresentPresent based on regional distribution.
-Western AustraliaPresentIntroduced Not invasive Randall, 2012; eMonocot, 2015Earliest record in 1958

History of Introduction and Spread

Top of page

In the USA, C. schoenoides was first introduced into eastern states in the late 1800s and then into California probably in the early 1900s (Hammel and Reeder, 1979; GBIF, 2015). C. schoenoides is eaten by waterfowl such as the northern pintail in California, and it is possible that these birds have aided its spread by seed (Fleskes et al., 2005).

Interestingly, however, there are no records for this species in the eastern states of the USA after about 1955 (Hammel and Reeder, 1979; GBIF, 2015).

C. schoenoides was first recorded in Coolup, Western Australia in 1958 (GBIF, 2015). There are no records to indicate how C. schoenoides was introduced. 

The species was first recorded as naturalized in Japan in 1998 (Koba and Tanaka, 2000; GBIF, 2015).

In Belgium this species is thought to have been introduced accidentally through imported grain in 1914 (Verloove, 2006).

Risk of Introduction

Top of page

C. schoenoides is known to be eaten by waterfowl, and the seeds are possibly spread by these birds (Naylor, 1999; Green et al., 2002; 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. schoenoides to one which does not. In Michigan, USA, it has been suggested that the species has been spread along salted roadsides (Reznicek et al., 2011).

Habitat

Top of page

This species often grows near waterbodies such as rivers, vernal pools and marshes and can tolerate saline conditions (Hammel and Reeder, 1979; Akhani, 2014; Flora of China Editorial Committee, 2015). In California this species is actively managed in wetlands to maximise seed production for waterfowl (Rahilly et al., 2012). In Australia, C. schoenoides is known as a weed of irrigated pastures (WSWA, 1998), and in China it is reported as weed on farmland (Randall, 2012). In Israel, it has been recorded as a weed in managed forests as a result of herbicide resistance (Heap, 2015). It also appears to be common along roadsides and other disturbed areas, especially in its introduced ranges (Reznicek et al., 2011).

Habitat List

Top of page
CategorySub-CategoryHabitatPresenceStatus
Terrestrial
 
Terrestrial – ManagedCultivated / agricultural land Secondary/tolerated habitat Harmful (pest or invasive)
Managed forests, plantations and orchards Present, no further details Harmful (pest or invasive)
Managed grasslands (grazing systems) Secondary/tolerated habitat Natural
Disturbed areas Principal habitat Natural
Rail / roadsides Principal habitat Natural
Terrestrial ‑ Natural / Semi-naturalRiverbanks Principal habitat Natural
Wetlands Principal habitat Harmful (pest or invasive)
Deserts Principal habitat Natural
Arid regions Principal habitat Natural
Littoral
Salt marshes Secondary/tolerated habitat Natural

Hosts/Species Affected

Top of page

C. schoenoides can be highly invasive in wetlands, particularly in California (Hammel and Reeder, 1979; Calflora, 2015) and is thought to negatively affect native wetland species in this region, such as Scirpus maritimus, Schoenoplectus acutus, Juncus balticus, Xanthium strumarium and Zannichellia palustris.

Biology and Ecology

Top of page

Genetics

C. schoenoides has a chromosome number of 2n = 32 and is distinguished by ploidy from its sister taxon, C. vaginiflora, which has a chromosome number of 2n = 48 (Hammel and Reeder, 1979; IPCN Chromosome Reports, 2015). Peterson et al. (2014) suggested incorporating Crypsis into the genus Sporobolus, because of its embedded position in a paraphyletic Sporobolus clade.

Reproductive Biology

Like most grasses, C. schoenoides is wind pollinated and has bisexual flowers. C. schoenoides is a prolific seed producer, at least in Californian wetlands, being the most productive species in terms of mass of seed produced in these wetlands (up to 1268 kg.ha-1 seeds produced) (Naylor, 1999). C. schoenoides has small seeds up to 1.5 mm long and with an average 1000 seed weight of 0.242 g (eMonocot, 2015; Royal Botanic Gardens Kew, 2015).

Physiology and Phenology

C. schoenoides is an annual (eMonocot, 2015). It uses the C4 photosynthetic pathway (Osborne et al., 2014) and is tolerant of saline conditions (Flora of Pakistan, 2015). In Pakistan the species flowers from July to August at higher elevations and from September to November at lower elevations (Flora of Pakistan, 2015). In California this species flowers from June to October (Calflora, 2015) and elsewhere in the USA from June to September (Hammel and Reeder, 1979).

Environmental Requirements

C. schoenoides grows in sandy, clay or sandy clay soils in wetlands, vernal pools, moist environments in mountainous areas, seasonally-flooded mud-flats, and saline/brackish pools in deserts (Hammel and Reeder, 1979; CalFlora, 2015; Flora of China Editorial Committee, 2015; Flora of Pakistan, 2015). Climate preferences and tolerances are based on overlaying distribution records of this species in a global map of Köppen-Geiger climate zones (Kriticos et al., 2011) and global temperature and precipitation layers (Hijmans et al., 2005).

Climate

Top of page
ClimateStatusDescriptionRemark
Aw - Tropical wet and dry savanna climate Tolerated < 60mm precipitation driest month (in winter) and < (100 - [total annual precipitation{mm}/25])
BS - Steppe climate Preferred > 430mm and < 860mm annual precipitation
BW - Desert climate Preferred < 430mm annual precipitation
Cf - Warm temperate climate, wet all year Preferred 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
Df - Continental climate, wet all year Preferred Continental climate, wet all year (Warm average temp. > 10°C, coldest month < 0°C, wet all year)
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 Ranges

Top of page
Latitude North (°N)Latitude South (°S)Altitude Lower (m)Altitude Upper (m)
51 34

Air Temperature

Top of page
Parameter Lower limit Upper limit
Mean annual temperature (ºC) 8 27
Mean maximum temperature of hottest month (ºC) 20.3 42.6
Mean minimum temperature of coldest month (ºC) -19.3 17.6

Rainfall

Top of page
ParameterLower limitUpper limitDescription
Mean annual rainfall621559mm; lower/upper limits

Means of Movement and Dispersal

Top of page

Natural Dispersal

The seeds of C. schoenoides are likely dispersed passively or by wind given their small size and low weight (Thomson et al., 2010).

Vector Transmission (Biotic)

C. schoenoides is a favourite forage species of waterfowl and may be dispersed by these birds (Naylor, 1999; Green et al., 2002; Fleskes et al., 2005).

Accidental Introduction

It is not known how this species was introduced into the USA or other non-native ranges, but given its small seed size and the lack of known uses by humans, it is probable that this species was introduced accidentally as a contaminant, possibly in imported pasture seed.

Impact Summary

Top of page
CategoryImpact
Economic/livelihood Positive
Environment (generally) Positive and negative

Impact

Top of page

In California, USA, C. schoenoides is very abundant in wetlands (Naylor, 1999; Calflora 2015). It is probably the most important forage species for waterfowl in this region (Fleskes et al., 2005; Rahilly et al., 2012), thereby having a positive economic (waterfowl popular for hunting) and biodiversity impact. However, because of its dominance in these habitats, it likely has a negative effect on plant biodiversity in Californian wetlands, with possible impacts on species such as Scirpus maritimus, Schoenoplectus acutus, Juncus balticus, Xanthium strumarium and Zannichellia palustris.

As a reported agricultural weed in Australian pasture (WSWA, 1998) and farmland in China (Randall, 2015), there may be economic impacts on livestock productivity.

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Has a broad native range
  • Abundant in its native range
  • Is a habitat generalist
  • Pioneering in disturbed areas
  • Fast growing
  • Has high reproductive potential
  • Has propagules that can remain viable for more than one year
Impact outcomes
  • Monoculture formation
Impact mechanisms
  • Competition - monopolizing resources
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field
  • Difficult/costly to control

Similarities to Other Species/Conditions

Top of page

This species is very similar to C. vaginiflora. However, it is distinguished by having pink-tinged stems and spikelets (not observed in C. vaginiflora), being taller (culms up to 75 cm compared to 30 cm), having longer leaf blades (12 cm compared to 5 cm), no disarticulation of leaf blades, glabrous collars, larger panicles (up to 3 cm long compared to 1.5 cm) and longer anthers (up to 0.9 mm compared to 0.7 mm) (Hammel and Reeder, 1979; eMonocot, 2015).

Prevention and Control

Top 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.

Control

There appears to be no specific literature for the control of C. schoenoides. 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). However, it is interesting to note that herbicide resistance (against Group C1/5 herbicides) in C. schoenoides was observed in two managed forests in Israel in 1995 (Heap, 2015).

Monitoring and Surveillance

Remote sensing has been used to successfully map seed production of C. schoenoides (Rahilly et al., 2012). This however has not been used as a tool for mapping this species for control efforts, but rather to estimate seed production for the purposes of predicting forage availability for waterfowl (Rahilly et al., 2012).

Gaps in Knowledge/Research Needs

Top of page

It would be useful to know more about the invasiveness of this species in other states of the USA, and to what extent it is problematic in regions such as Australia and Japan. More information is needed on the abundance of this species, both in its native and non-native ranges. It would also be useful to know where this species appears to have expanded beyond its historical native range (in much of Eurasia and Africa).  Nothing is known about how C. schoenoides spreads outside of its native range. This knowledge would help prevent its introduction elsewhere. It would also be useful to confirm whether waterfowl are indeed dispersing the seeds of this species locally. More information is needed on whether and how this species impacts native biodiversity and what, if any, economic and social impacts it is having where it has become invasive.

References

Top of page

Akhani H, 2014. Crypsis schoenoides. The IUCN Red List of Threatened Species. Version 2014.3. http://www.iucnredlist.org

Calflora, 2016. Information on California plants for education, research, and conservation. Berkeley, California, USA: Calflora Database. http://www.calflora.org

DAISIE, 2015. Delivering Alien Invasive Species Inventories for Europe. European Invasive Alien Species Gateway. www.europe-aliens.org/default.do

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 of China Editorial Committee, 2015. Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=2

Flora of Pakistan, 2015. Flora of Pakistan/Pakistan Plant Database (PPD). Tropicos website. USA: St. Louis, Missouri and Cambridge, Massachusetts. http://www.tropicos.org/Project/Pakistan

GBIF, 2015. Global Biodiversity Information Facility. http://www.gbif.org/species

Green AJ; Figuerola J; Sánchez MI, 2002. Implications of waterbird ecology for the dispersal of aquatic organisms. Acta Oecologica, 23(3):177-189.

Hammel BE; Reeder JR, 1979. The genus Crypsis (Gramineae) in the United States. Systematic Botany, 4(4):267-280.

Heap I, 2015. The international survey of herbicide resistant weeds. www.weedscience.org

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/

Koba H; Tanaka N, 2000. Crypsis schoenoides (L.) Lam., newly naturalized in Japan. Journal of Japanese Botany, 75(4):262-263.

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/

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.

NOBANIS, 2015. North European and Baltic Network on Invasive Alien Species. http://www.nobanis.org/

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.

Reznicek AA; Voss EG; Walters BS, 2011. Michigan Flora Online. Ann Arbor, Michigan, USA: University of Michigan. http://michiganflora.net

Royal Botanic Garden Edinburgh, 2015. Flora Europaea. Edinburgh, UK: Royal Botanic Garden Edinburgh. http://rbg-web2.rbge.org.uk/FE/fe.html

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/

TALA, 2015. The Atlas of Living Australia. Canberra, Australia: ALA. http://www.ala.org.au/

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

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/

Verloove F, 2006. Catalogue of neophytes in Belgium (1800-2005). Scripta Botanica Belgica, 39: 89 pp. http://alienplantsbelgium.be/sites/alienplantsbelgium.be/files/tabel_2.pdf

WSWA, 1998. Western Weeds: A guide to the weeds of Western Australia (online edition). Perth, Australia: The Weeds Society of Western Australia (Inc.). http://wswa.org.au/western_weeds.htm#contents

Contributors

Top of page

27/03/15 Original text by:

Vernon Visser, Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, South Africa

Distribution Maps

Top of page
You can pan and zoom the map
Save map