Myriophyllum pinnatum
(cutleaf watermilfoil)

Identity

Preferred Scientific Name

• Myriophyllum pinnatum (Walter) Britton, Sterns & Poggenb.

Preferred Common Name

• cutleaf watermilfoil

Other Scientific Names

• Myriophyllum scabratum Michx.
• Potamogeton pinnatum Walter

International Common Names

• English: foxtail green; green foxtail; green myrio
• Spanish: cola de zorra verde; milenrama; ramo-cola de zorra

Local Common Names

• Canada: cutleaf water-milfoil; green parrot’s feather
• Cuba: miriofilum; pinillo
• Hungary: grϋnes tausenblatt; stolístek zpeřeny; zierliches tausendblatt
• USA: alternate-leaved water-milfoil; Eastern water-milfoil; foxtail moss; pinnate water-milfoil; rooted coontail; rough water milfoil

Summary of Invasiveness

Myriophyllum pinnatum is a perennial aquatic herb only reported as invasive in Cuba, where it is included in the management plan of the Ciénaga de Zapata Biosphere Reserve as a species that needs to be managed to prevent invasion of that wetland system. In some areas of its native range in North America, it is considered rare, endangered or extirpated due to habitat fragmentation and loss. In the USA, the species is considered endangered in Connecticut, Massachusetts, Indiana, New Jersey, New York, Rhode Island and Tennessee. M. pinnatum belongs to a genus recognized for the invasive species M. spicatum, M. aquaticum and M. heterophyllum. 

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Haloragidales
•                         Family: Haloragidaceae
•                             Genus: Myriophyllum
•                                 Species: Myriophyllum pinnatum

Notes on Taxonomy and Nomenclature

Myriophyllum is one of the most species rich aquatic genera, with about 68 species spread worldwide (Moody and Les, 2010). The word Myriophyllum comes from the Greek, meaning many leaves and pinnatum means feather-like (SEINet, 2017). Species identification in this genus is difficult without the presence of reproductive structures.

Description

Perennial aquatic or semi-aquatic herb. Stem highly variable, rooting in mud and freely branching or elongating in deeper water. Leaves alternate and whorled on same plant, pinnately divided, with submersed leaves having three to five pairs of divisions. Emersed leaves are 0.5-3 cm long, linear to lance-shaped, and have comb-like divisions or sharp teeth. Flowers either male or female, found on the same plant (monoecious), some bisexual, borne in a terminal spike above the water surface, with male flowers near the inflorescence tip. Bracts are longer than male flowers, triangular, with six to ten 1-2 mm long teeth that are angled toward the tip. Flowers green to purplish, small, four-parted, with 1.5-2 mm long petals that are rounded above and narrow-clawed. Fruit is a deeply four-lobed nut-like cluster, pale, 1.3-2 mm long, egg-shaped to cubic, splitting into four one-seeded segments that are flat-sided with two spiked ridges. Winter buds absent (Red de Herbarios del Noroeste de México, 2017).

Plant Type

Distribution

M. pinnatum is native to North America, with evidence of its presence in Iowa since the Holocene (Baker et al., 1996; USDA-NRCS, 2017). Urquiola Cruz and Betancourt Gandul (2000) consider the species native to Cuba, but Maldonado González (2009-2010) and Oviedo Prieto et al. (2012) list it as introduced in the country. M. pinnatum has also been introduced to Mexico (in 1974) and to Jamaica (in 1976) (Proctor, 1982; Red de Herbarios del Noroeste de México, 2017). Although the species is not listed as naturalized elsewhere, it is sold commercially worldwide and on the internet to be used in freshwater aquaria.

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.

Risk of Introduction

M. pinnatum is an aquatic herb with a low to medium risk of introduction. Although it is available commercially at aquarium supply stores, its specific water temperature and pH might limit its distribution (Live Aquaria, 2017). Where used only as a plant for indoor aquaria, the threat to natural environments is low. It can become problematic if its popularity increases or if used in sewage treatment plants (Mohan et al., 2010; Live Aquaria, 2017).

Habitat

M. pinnatum occurs in shallow water, in ditches and ponds, usually less than 1 m deep (Knepper et al., 2002; SEINet, 2017). It is also reported from forest swales, wetlands, creeks, borders of brackish marshes, swamps and rivers (Fernald, 1936; Abbott and Judd, 2000; Rosen et al., 2003; Hercombe et al., 2007; Maldonado González, 2009-2010). 

Habitat List

Biology and Ecology

Genetics

The chromosome number reported for M. pinnatum is n = 5 (Moody and Les, 2002). DNA barcode information for the species is available at the Barcode of Life Data Systems (BOLD, 2017). Although hybridisation with M. heterophyllum was initially reported by Moody and Les (2002), the same authors later confirmed it to be between M. heterophyllum and M. laxum (Moody and Les, 2010).

Reproductive Biology

M. pinnatum reproduces by cuttings and by flowers, if tips are left to grow outside of water (Live Aquaria, 2017). Propagation procedures in vitro have been developed for the species by Kane and Gilman (1991).

Physiology and Phenology

M. pinnatum is a rapid growing aquatic herb that can grow partially above water (Live Aquaria, 2017). It is reported to flower in July (SEINet, 2017).

Associations

Sorrie (1987) reports the species to occur in small, shallow, muddy, brackish ponds, together with Typha latifolia, Phragmites communis [Phragmites australis], Eleocharis smallii [Eleocharis palustris], Scirpus validus [Schoenoplectus tabernaemontani], Hibiscus palustris [Hibiscus moscheutos], Ludwigia palustris, Proserpinaca palustris and occasionally Diplachne maritima [Leptochloa fusca subsp. fascicularis]. In some cases, P. australis can be a threat to M. pinnatum populations, by severely reducing the open water and exposed mud available.

Environmental Requirements

Most information available concerns cultivation of M. pinnatum as an aquarium plant. The species grows in shallow water in full to partial shade, at water temperatures of 16-24°C. It grows in clay, sand, limestone and gravel substrates, with water pH of 6.5-7.5 and water hardness of 3-8 mg/l CaCO₃ (Maldonado González, 2009-2010; Live Aquaria, 2017).

Although information about environmental requirements from natural habitats is lacking, the species is likely able to tolerate freezing temperatures, given the fact that it is native in Canada (Missouri Botanical Garden, 2017).

Climate

Latitude/Altitude Ranges

Air Temperature

Soil Tolerances

Soil drainage

• impeded

Soil texture

• heavy
• light
• medium

Water Tolerances

Natural enemies

Notes on Natural Enemies

The species is foraged by Procambarus clarkii, P. spiculifer, Branta canadensis and Aix sponsa (Drobney and Fredrickson, 1979; Cronin et al., 2002; Parker et al., 2007).

Means of Movement and Dispersal

Intentional Introduction

M. pinnatum is widely used as an aquarium plant (Live Aquaria, 2017). Because of this, it is sold commercially at aquarium supply stores worldwide and on the internet, which facilitates its spread.

The species is also maintained as part of the permanent National Botanical Garden collection in Cuba (Maldonado González, 2009-2010).

Pathway Causes

Pathway Vectors

Environmental Impact

In Cuba, M. pinnatum is considered a transformer species and listed as invasive (Oviedo Prieto et al., 2012). 

Social Impact

M. pinnatum has been associated with larvae of the malaria transmitting Anopheles mosquito (Penfound, 1942).

Risk and Impact Factors

• Proved invasive outside its native range
• Has a broad native range
• Fast growing
• Has high reproductive potential
• Gregarious
• Has propagules that can remain viable for more than one year
• Reproduces asexually

• Highly likely to be transported internationally deliberately

Uses

Economic Value

M. pinnatum is sold by aquarium shops and on internet websites. In some websites it is listed as being farm-raised for aquarium sales (Live Aquaria, 2017).

Social Benefit

M. pinnatum is reported as having some antimicrobial activity (Nickell, 1959). It is recommended for sewage treatment systems, as it improves dissolved oxygen levels in water, providing a good habitat for bacteria growth (Mohan et al., 2010).

Environmental Services

M. pinnatum provides coverage and protection to newborn fish and tadpoles (Morin, 1981; Live Aquaria, 2017). It is foraged by the crayfishes Procambarus clarkii and P. spiculifer, the Canada goose Branta canadensis and the wood duck Aix sponsa (Drobney and Fredrickson, 1979; Cronin et al., 2002; Parker et al., 2007). It is a host species for aquatic and semiaquatic Lepidoptera (Minno, 1992).

Uses List

Animal feed, fodder, forage

• Fodder/animal feed

Environmental

• Amenity

General

• Botanical garden/zoo
• Pet/aquarium trade

Similarities to Other Species/Conditions

M. pinnatum has both alternate and whorled leaves, while other Myriophyllum species have only whorled leaves (SEINet, 2017). The species is similar to M. farwellii, but the fruits are smaller in M. pinnatum. Also, the carpels of M. pinnatum are broadly two-winged on the back, strongly scabrate or toothed and deeply grooved between the wings, while in M. farwellii carpels are roughly tuberculate or slightly toothed and with shallow groves between them (Morong, 1891).

Prevention and Control

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.

Prevention

M. pinnatum is included in the Ciénaga de Zapata Biosphere Reserve management plan as a species that needs to be managed in order to prevent its spread in this wetland system (Oviedo Prieto et al., 2012).

Gaps in Knowledge/Research Needs

More detailed information about the species impacts on invaded habitats or on other species is needed. Details about its biology and environmental requirements in natural habitats are also needed.

References

Abbott, J. R., Judd, W. S., 2000. Floristic inventory of the Waccasassa Bay State Preserve, Levy County, Florida. Rhodora, 102(912), 439-513.

Acevedo-Rodríguez P, Strong MT, 2012. Catalogue of seed plants of the West Indies. Smithsonian Contributions to Botany, 98:1-1192. Washington DC, USA: Smithsonian Institution

Backus, R. H., Polloni, P. T., Reid, B. L., Somers, P., Hendrickson, T. O., 2002. The flora of Penikese Island, Massachusetts: the fifth survey (1998-1999), with emphasis on the woody vegetation. Rhodora, 104(919), 219-252.

Baker, R. G., Bettis, E. A., III, Schwert, D. P., Horton, D. G., Chumbley, C. A., Gonzalez, L. A., Reagan, M. K., 1996. Holocene paleoenvironments of northeast Iowa. Ecological Monographs, 66(2), 203-234. doi: 10.2307/2963475

BOLD, 2017. The Barcode of Life Data Systems. http://www.boldsystems.org/index.php/TaxBrowser_Home

Couch, R. W., Nelson, E. N., 1983. Myriophyllum in Oklahoma, USA. Proceedings of the Oklahoma Academy of Science, 63, 103-104.

Cronin, G., Lodge, D. M., Hay, M. E., Miller, M., Hill, A. M., Horvath, T., Bolser, R. C., Lindquist, N., Wahl, M., 2002. Crayfish feeding preferences for freshwater macrophytes: the influence of plant structure and chemistry. Journal of Crustacean Biology, 22(4), 708-718. doi: 10.1651/0278-0372(2002)022[0708:CFPFFM]2.0.CO;2

Drobney, R. D., Fredrickson, L. H., 1979. Food selection by wood ducks in relation to breeding status. Journal of Wildlife Management, 43(1), 109-120. doi: 10.2307/3800641

EOL, 2017. Encyclopedia of Life. http://eol.org/

Fernald, M. L., 1936. Plants from the outer coastal plain of Virginia. Rhodora, 38, 376-404; 414-452.

Hercombe PA, Elsik IS, Pruess WW, Brown LE, 2007. The vascular flora of a woodland park site in east Harris County, Texas. Journal of the Botanical Research Institute of Texas, 1(1):693-711

Hill SR, 1986. An annotated checklist of the vascular flora of Assateague Island (Maryland and Virginia). Castanea, 51(4):265-305

Kane, M. E., Gilman, E. F., 1991. In vitro propagation and bioassay systems for evaluating growth regulator effects on Myriophyllum species. Journal of Aquatic Plant Management, 29, 29-32.

Knepper DA, Johnson DM, Musselman LJ, 2002. Marsilea mutica in Virginia. American Fern Journal, 92(3):243-244

Lamont, E. E., Stalter, R., 2013. Flora of Plum Island, Suffolk County, New York. Journal of the Torrey Botanical Society, 140(4), 465-479. http://www.bioone.org/loi/tbot doi: 10.3159/TORREY-D-13-00016.1

Live Aquaria, 2017. Quality aquatic life directly to your door. Wisconsin, USA: Doctors Foster and Smith. http://www.liveaquaria.com

Maldonado González SG, 2009-2010. The collection of aquatic plants of Cuba National Botanical Garden. (La colección de plantas acuáticas del Jardín Botánico Nacional de Cuba). Revista del Jardín Botánico Nacional, 30/31:15-20

Minno, M. C., 1992. Lepidoptera of the Archbold biological station, Highlands county, Florida. Florida Entomologist, 75(3), 297-329. doi: 10.2307/3495853

Missouri Botanical Garden, 2017. Tropicos database. http://www.tropicos.org/

Mohan SV, Mohanakrishna G, Chiranjeevi P, Sarma P, 2010. Ecological engineered system (EES) designed to integrate floating, emergent and submerged macrophytes for the treatment of domestic sewage and acid rich fermented-distillery wastewater: evaluation of long term performance. Bioresource Technology, 101(10):3363-3370

Moody, M. L., Les, D. H., 2002. Evidence of hybridity in invasive watermilfoil (Myriophyllum) populations. Proceedings of the National Academy of Sciences of the United States of America, 99(23), 14867-14871. doi: 10.1073/pnas.172391499

Moody, M. L., Les, D. H., 2010. Systematics of the aquatic angiosperm genus Myriophyllum (Haloragaceae). Systematic Botany, 35(1), 121-139. http://www.bioone.org/doi/full/10.1600/036364410790862470 doi: 10.1600/036364410790862470

Moore G, 1989. A checklist of the vascular plants of Cumberland County, New Jersey. Bartonia, 55:25-39

Morin PJ, 1981. Predatory salamanders reverse the outcome of competition among three species of anuran tadpoles. Science, 212(4500):1284-1286

Morong T, 1891. Myriophyllum farwellii, nov. sp. Bulletin of the Torrey Botanical Club, 18(5):146-147.

Nickell, L. G., 1959. Antimicrobial activity of vascular plants. Economic Botany, 13, 281-318. doi: 10.1007/BF02885664

Oviedo Prieto R, Herrera Oliver P, Caluff MG, et al., 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba, 6(Special Issue 1):22-96

Parker, J. D., Burkepile, D. E., Collins, D. O., Kubanek, J., Hay, M. E., 2007. Stream mosses as chemically-defended refugia for freshwater macroinvertebrates. Oikos, 116(2), 302-312. http://www.blackwell-synergy.com/servlet/useragent?func=showIssues&code=oik doi: 10.1111/j.0030-1299.2007.15289.x

Patrick TS, Wofford BE, Webb DH, 1983. State records and other recent noteworthy collections of Tennessee plants. IV. Castanea, 48(2):109-116

Penfound, W. T. , 1942. The Relation of Plants to Malaria Control with special Reference to impounded Waters. Public Health Reports, 57(8), 261-268 pp. doi: 10.2307/4584019

Proctor GR, 1982. More additions to the flora of Jamaica. Journal of the Arnold Arboretum, 63(3):199-315

Radford AE, 1951. Distribution of some rarely collected vascular aquatic plants in North Carolina. Castanea, 16(3):85-91

Red de Herbarios del Noroeste de México, 2017. Flora del Noroeste dé Mexico. Sonora, Mexico: Herbario de la Universidad de Sonora. http://herbanwmex.net/portal/taxa/index.php

Rosen DJ, Jones SD, Rettig VE, 2003. A floristic survey of Big Branch Marsh National Wildlife Refuge, St. Tammany Parish, Louisiana. Sida, 20(3):1189-1216

Scribailo RW, Alix MS, 2002. New records with ecological notes for rare aquatic vascular plants in Indiana. Part 1. Rhodora, 104(920):373-395

SEINet, 2017. Arizona - New Mexico Chapter. Regional Networks of North American Herbaria Symbiota. http://swbiodiversity.org/seinet/taxa/index.php

Snyder D, 2000. One hundred lost plants found. Bartonia, 60:1-22.

Sorrie BA, 1987. Notes on the rare flora of Massachusetts. Rhodora, 89(858):113-196

Suiter DW, Evans DK, 1999. Vascular flora and rare species of New River Gorge National River, West Virginia. Castanea, 64(1):23-49

Tucker A, Dill NH, 1993. The collections of Albert Commons of Delmarva, 1861-1901, with attention to August 4-5, 1874 and September 9-10, 1875. Bartonia, 57:9-15

Urquiola Cruz AJ, Betancourt Gandul M, 2000. The Halograceae of Cuba. (Las Halograceae de Cuba). Anales del Jardín Botánico de Madrid, 57(2):327-332

USDA-NRCS, 2017. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Zaremba RE, Lamont EE, 1993. The status of the coastal plain pond shore community in New York. Bulletin of the Torrey Botanical Club, 120(2):180-187

Distribution References

Acevedo-Rodríguez P, Strong M T, 2012. Catalogue of the Seed Plants of the West Indies. Washington, DC, USA: Smithsonian Institution. 1192 pp. http://botany.si.edu/Antilles/WestIndies/catalog.htm

Backus R H, Polloni P T, Reid B L, Somers P, Hendrickson T O, 2002. The flora of Penikese Island, Massachusetts: the fifth survey (1998-1999), with emphasis on the woody vegetation. Rhodora. 104 (919), 219-252.

CABI, Undated. Compendium record. Wallingford, UK: CABI

Couch R W, Nelson E N, 1983. Myriophyllum in Oklahoma, USA. Proceedings of the Oklahoma Academy of Science. 103-104.

EOL, 2017. Encyclopedia of Life., http://eol.org/

Hill SR, 1986. An annotated checklist of the vascular flora of Assateague Island (Maryland and Virginia). In: Castanea, 51 (4) 265-305.

Lamont E E, Stalter R, 2013. Flora of Plum Island, Suffolk County, New York. Journal of the Torrey Botanical Society. 140 (4), 465-479. http://www.bioone.org/loi/tbot DOI:10.3159/TORREY-D-13-00016.1

Missouri Botanical Garden, 2017. Tropicos database., http://www.tropicos.org/

Moore G, 1989. A checklist of the vascular plants of Cumberland County, New Jersey. In: Bartonia, 55 25-39.

Oviedo Prieto R, Herrera Oliver P, Caluff M G, et al, 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba. 6 (Special Issue No. 1), 22-96.

Patrick TS, Wofford BE, Webb DH, 1983. State records and other recent noteworthy collections of Tennessee plants. IV. In: Castanea, 48 (2) 109-116.

Proctor GR, 1982. More Additions to the Flora of Jamaica. In: Journal of the Arnold Arboretum, 63 (3) 199-316.

Radford AE, 1951. Distribution of some rarely collected vascular aquatic plants in North Carolina. In: Castanea, 16 (3) 85-91.

Red de Herbarios del Noroeste de México, 2017. (Flora del Noroeste dé Mexico)., Sonora, Mexico: Herbario de la Universidad de Sonora. http://herbanwmex.net/portal/taxa/index.php

Scribailo RW, Alix MS, 2002. New records with ecological notes for rare aquatic vascular plants in Indiana. Part 1. In: Rhodora, 104 (920) 373-395.

Snyder D, 2000. One hundred lost plants found. In: Bartonia, 60 1-22.

Suiter DW, Evans DK, 1999. Vascular flora and rare species of New River Gorge National River, West Virginia. In: Castanea, 64 (1) 23-49.

Tucker A, Dill NH, 1993. The collections of Albert Commons of Delmarva, 1861-1901, with attention to August 4-5, 1874 and September 9-10, 1875. In: Bartonia, 57 9-15.

USDA-NRCS, 2017. The PLANTS Database. Greensboro, North Carolina, USA: National Plant Data Team. https://plants.sc.egov.usda.gov

Zaremba RE, Lamont EE, 1993. The status of the coastal plain pond shore community in New York. In: Bulletin of the Torrey Botanical Club, 120 (2) 180-187.

Links to Websites

Contributors

28/02/17 Original text by:

Jeanine Vélez-Gavilán, Department of Biology, University of Puerto Rico,  Mayaguez, Puerto Rico, USA 

Distribution Maps