Introduction:
Typha latifolia (cattails) are among the most common of all aquatic plants. They are often a nuisance but also perform an important function in keeping a lake healthy by filtering the runoffs. Typha latifolia form dense monocultures when there is a wetland disturbance. They can reach up to 2 or 3 metres and grow prolifically from thick underground rhizomes, forming dense rhizome mats and litter which has an impact on species diversity by alteration of habitat. Dense Typha latifolia growth and litter may reduce the opportunity for other plants to establish or survive.
Description:
Typha latifolia are very densely packed with tiny flowers, male flowers in top cluster and female flowers in bottom cluster. Stems can be more than one foot long. Leaves are straplike and stiff; rounded on back; flat and D shaped. Leaves are straight in the bottom half but twisted and spiral in the top. Leaves are thick and pale grayish-green in colour. It flowers during May and June. The fruit is tiny and tufted nutlet. Cattail can be distinguished by the following “male flowers are brown, minute, >1.3cm long, thickly clustered, anthers 1-3mm long. Female flowers are tiny, 2-3mm long when in flower, 10-15mm long when in fruit. Female fruiting spike are pale green when in flower, drying to brownish, later blackish brown or reddish brown in fruit. Seed are minute and numerous”.
Occurs in:
Coastland, estuarine habitats, lakes, riparian zones, water courses, wetlands.
Habitat description:
Wetland plant communities from deep marshes to open bogs, growing on wet substrates and often in 1-2 feet or more of standing water. It grows where soil remains wet, saturated or flooded most of the growing season, in shallow freshwater and occurs in slightly blackish marshes. It prefers soil with high amounts of organic matter and can also grow on fine texture mineral soils.
General impacts:
Impacts of the genus Typha state that they form dense monocultures when there is a wetland disturbance. They have the ability to spread rapidly by vegetative reproduction forming forming dense rhizome mats and litter. This has an impact on species diversity by alteration of habitat. Dense Typha growth and litter may reduce the opportunity for other plants to establish or survive. They rapidly close any open water giving few oppurtunities for other plants to establish.
Geographical range:
Native range: Alaska, Continental US, Hawai‘i. Africa (Algeria; Morocco; Ethiopia; Kenya; Tanzania; Uganda and Nigeria); Asia -temperate (Afghanistan; Iran; Israel; Jordan; Lebanon; Syria; Turkey; Armenia; Azerbaijan; Georgia; Russian Federation – Ciscaucasia, Dagestan; Russian Federation; Kazakhstan; Kyrgyzstan; Turkmenistan; Uzbekistan; Mongolia; China and Japan); Asia – tropical (Pakistan); Europe (Denmark; Finland; Ireland; Norway; Sweden; United Kingdom; Austria; Belgium; Czechoslovakia; Germany; Hungary; Netherlands; Poland; Switzerland; Belarus; Estonia; Latvia; Lithuania; Moldova; Russian Federation – European part; Ukraine; Albania; Bulgaria; Greece; Italy; Romania; ex-Yugoslavia; France; Portugal; Spain), Northern America (Canada, USA); Southern America (Guatemala; Mexico; Brazil; Argentina; Paraguay).
Known introduced range: Naturalised in Australia, present in New Zealand, South America and the Caribbean.
Management information:
Physical: Control techniques of fire and physical removal (cutting) in conjunction with flooding are most appropriate.Draining techniques used in wetlands can inhibit growth. If the wetland can be drained and then burned during summer, typha will not be able to survive with no water over winter. There have however been no controlled experiments carried out to demonstrate this method. Deep flooding can also cause declines in infestations.
An effective control of Typha can be achieved by a combination of hand or mechanical cutting of stems followed by submergence of the remaining stems. Best results have been achieved by two clippings followed by submergence to at least 7.5cm or 3inches. typha are not shade tolerant, shading using black polyethylene tarps has been tried for killing growth. Degradation of the polyethylene tarps and problems of holding them down are some problems.
Manual removal works best for small seedlings. They are easy to pull out in damp soil, care must be taken to see that all rhizome bits are removed otherwise the plants can reestablish itself.
Mechanical: Mechanical removal of rhizomes is difficult because of their depth and volumn, however it can be used to reduce size of infestations and by following up with manual removal. The advantages of mechanical and manual removal are that no herbicide is used in water. Care should also be taken to ensure that the excavated material is taken away from the site and killed.Exposure of rhizomes to frost by cultivation of the site is a good method when water levels are low.
Chemical: Treating typha when flowering using herbicides has been found to cause the greatest stress. The disadvantage however of using herbicides is the large volumn of decaying matter that remains which can cause water to go foul and unusable. Wick and spray applications of Roundup followed by with follow-up treatements has been found to be effective.
Treatment with herbicides like Dalpan followed up by respraying growing tips and making sure that the stems are submerged has been found to be successful.
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