Chara species

Synonyms -

Family: - Characeae


Stoneworts - because the plants often have gritty limestone deposits (stones) in or on them and wort means weed.

Other Names:

Muskgrass - because they often taint water.


An anchored green algae that grows under water and looks like a vascular plant with "leaves" in rings around the "stems" that are often about 30 cm long. They often have a garlic like odour.





Large individual cells that are sometimes covered by a layer (cortex) of small cells. They often have deposits on the "leaves" and feel gritty to touch. In whorls around the stem and often grey green.

Stipules - None

Petiole - None

Blade - round


Jointed, solid between the nodes.

Often encrusted with lime and may remain intact after the plant dies.

Unbranched, jointed, solid between the nodes, round and less than 1 mm diameter.

"Flower head:"

Orange or green pin head sized spheres on the stems.


No flowers.


Orange or green, pin head sized, ellipse bodies (oogonia) containing eggs at the nodes and similar spherical bodies (antheridia) containing sperm develop below the oogonia at the nodes.




Colourless rhizoids attach the plant to the pond bed.

Rhizoids are gravitropic 190.

Key Characters:

No true leaves.

"Leaves" in whorls.

Unbranched, solid, jointed stems.

Small round pin head sized fruiting bodies at the nodes.


Life cycle:

After fertilization the oospore remains dormant for some time then germinates. The plant grows underwater and is usually attached to the bottom. Fragments may form new plants. Motile sperm is released and eggs are fertilized.

Active growth starts in early spring and slows from mid summer to winter (Sabbatini, 1986).


Growth rates around 10 g dw/m2/day (100 kg/ha/day) are recorded in spring.


Reproduces by oospores and fragments.

Depth of water doesn't affect germination of Chara zeylanica and Chara fibrosa but water less than 10 cm deep reduces apical growth and overall biomass 191.

Flowering times:

Seed Biology and Germination:

Oospores are dormant for some time after fertilization.

Vegetative Propagules:

Stem fragments can form new plants.



Population Dynamics and Dispersal:

Chara tends to predominate at intermediate water depths 192.

Chara often dominates after control of other aquatic vascular plants 193.

Origin and History:

Native to the US.




Prefers static or slow moving water that is 1-6 m deep and is often common in ponds and major drains especially if the water is high in calcium. It often only noticed when the water levels drop and expose it.




Grows submerged in water and is attached to the bottom mud.

Plant Associations:

Usually associated with other water plants such as Pondweeds (Potamogeton spp.), filamentous algae (Cladophora), Lemma spp. Azolla spp., Myriophyllum spp.



Provide food and cover for aquatic life.

Chara tends to suppress other water weeds 194;195.

Chara globularis reduces mosquitoes probably by producing juvenile hormone-like compounds 196-198 and is used to reduce mosquito breeding in ponds in the US 199.

Chara wallichii contains anti fungal and anti bacterial compounds 200.

Used in recovery of eutrophic lakes in the Netherlands 201.

Chara canescens used for extracting selenium form agricultural drainage waters 202.

Used for removing mercury from water 203.

Used to clean up tannery effluent 204.

Male sex organs of Chara tomentosa have peptides that affect gene expression in other species 205.

Extracts increase cereal germination but may decrease germination of other species 206.


Weed of channels, fisheries, marron ponds, reservoirs, rice.

Weed of rice in Australia 207,

Chara tends to taint water 194.

Chara tends to support snail populations and little other fauna 208.

Reduces rice yields by consuming nitrogen and inhibiting tillering 209.






Management and Control:

Low light conditions created by dense crop canopy or turbidity, low pH, low concentrations of phosphorus in water, shallow water depth and frequent wetting-drying of soil after oospore germination reduces growth.


Mechanical control is generally not effective because it grows from fragments.

210 has data on vertebrate removal during harvesting.

Dredging or covering sediments (with sand, gravel and plastic) failed to provide long-term suppression of Chara 211.

Black polythene sheets 0.004 mm thick paced on bottom of ponds controls Chara 212.

About 500 g of fish are removed per 100 kg of water removed mechanically 213.


Deficiencies in oxygen saturation produced a 20-30 cm thick mat of Chara species 214.


Chara increased in high N and NP conditions in shallow water situations 215.


Covering with black polythene provides good control 216.

Induce phytoplankton blooms by adding mineral fertilizers 212.

Aquashade, a water soluble blue dye provided control of Chara by providing shading. It has a half life of 1-2 months and it longevity is decreased where clay is present 217.

218 has looked at competitive plants and shading plants for control of Chara.

Chemical Control


2,4-D butoxyethanol ester 29% at168 kg product/ha provided good control of Chara vulgaris and treated water safe for application to common crops and for mammalian drinking water 219.

40 kg/ha (200 kg/ha product) 2,4-D, butoxyethanol ester granules spread on a lake used for domestic water followed by 8 kg/ha copper sulphate gave good control in Texas 220.

1.5 kg a.e./ha 2,4-D sodium applied 40 days after sowing rice provided good control 221.


2 ppm applied over 3-6 hours controlled Chara contraria over 10 km of channel 222.


2 kg /ha was tested by 223.


1.5 kg/ha gave reasonable control 30 days after treatment 224.

Sand mix application of Butachlor to moist soil around rice germination provided control of Chara zeylanica 225.


Draw down applications of 20 kg chlorfenac provided good control but injection of 3 ppm chlorfenac did not 216.

Chlorthiamid 7.5 %

220 kg prod/ha provided good control of Chara vulgaris and treated water safe for application to common crops and for mammalian drinking water 219.

Copper Sulphate

20 kg/ha used in rice in India 226.

12 kg/ha gave good control 30 days after treatment 224.

50 kg copper sulphate pentoxide applied in a perforated container to give 1-2 ppm over 24 hours in water at velocity 0.6 km/hr gave good control of Chara contraria over 1-1.5 km stretches of channel 227.

A single application of copper sulphate at 2 or 5 ppm gave good control in channels 222.

In ditches, 50 kg pentahydrated copper sulphate at 1 km intervals is better than 150 kg every 3 km as concentration tends to drop below the required 2 ppm after 2 km in Colorado drainage ditches 228.

Not controlled by copper sulphate in India 229.

Chelated copper compounds were more active than copper sulphate and water hardness had little effect 230.

Pentahydrated copper sulphate halved growth rate and stopped zoospore production but didn't stop reinfestation (Sabbatini, 1986).

Chara is surviving chelated copper algaecide controls 231.

Copper triethanolamine complex (Cutrine) as a drip feed in flowing water plus and minus diquat provided good control of Chara 232.


50-150 ppm gave good control of Chara and Nitella 233.

0.05-0.2 ppm applied at any time of active growth gave season long control of Chara and other algae 234.

Dicopper dihydroxide carbonate (55.8% elemental copper or malachite

15-25 kg/ha provides good control of Chara species and other algae and is less toxic than copper sulphate to fish with LC50's around >1800 ppm 235.


Provided only transitory effects on Chara 236.

1 ppm controlled Chara delicatula and control seemed better at lower rates as it had less effect on zooplankton which gave longer lasting control 237.


1 ppm diquat was not successful 216.


10 ppm stopped sperm production in Char corallina and 50 ppm killed Chara zeylanica within 72 hours 238.


Results with Chara depend on the formulation used.

Treatment caused large growth of Chara species 239.

3 ppm endothal dipotassium 10.1% product or 7 ppm endothal mono(N,N-dimethylalkylamine 23.3% liquid) 7 ppm provided good control of Chara vulgaris and treated water safe for application to common crops and for mammalian drinking water 219.

Diquat plus mono(dimethyltridecylamine) and mono(N,N-dimethylalkylamine) salts of endothal provided good control of Chara. Diquat plus dihydroxyaluminium salt of endothal provided slow kill of aquatic weeds with Chara becoming dominant over time 240.

Endothal was ineffective on Chara corallina and Chara globularis in NZ 236.

Chara fibrosa tolerated 50 ppm of the potassium salt of endothal 241.


3 ppm fluridone was not satisfactory 216.


1 kg/ha gave good control 30 days after treatment 224.


1 ppm gave complete control of Chara but reduced oxygen concentration from 8 ppm to 0.2 ppm and resulted in fish deaths 4 days after treatment and no phytotoxic residues were present 15 months after treatment 242.

0.2 ppm controlled Chara in outside aquaria 243. Phytotoxic concentrations may persist for 8 months.

Hydrogen peroxide

10 or 20 ppm gave good control of Chara species 244.

Mahua cake (Madhuca longifolia) provides control at 120 kg/ha 226.


Provided control at 70 ppm 229.


2 kg/ha gave reasonable control 30 days after treatment 224.

2 kg/ha gave control of Chara zeylanica in rice 223.


2 kg a.i./ha nabam applied 40 days after sowing rice provided good control 221.


2 kg/ha pre emergent on rice gave good Chara control and similar to 16 kg/ha Copper sulphate. 0.74 kg/ha Oxadiazon plus 0.74 kg/ha copper sulphate applied pre emergent was more effective. Post emergence applications were ineffective 245.

1 kg/ha gave control of Chara zeylanica in rice 223.


0.6 ppm did not control Chara globularis in fisheries 246

Chara builds up after water milfoil or pondweed was controlled with 1 ppm paraquat in a fishery 247 and paraquat was not detectable in water 14 days after treatment and peak concentrations in mud occurred on day 16 248.

PCP pentachlorophenol

2.5-3.75 kg/ha sodium pentachlorophenate or 3.75-4.4 kg/ha PCP provided good control when applied 21 days before or 60 days after transplanting rice without affecting the crop but was toxic to small fish and snails 249.


1 kg/ha gave good control 30 days after treatment 224.

PH4062 or PH40:62

0.25 ppm had no effect on Chara but was good on other algae 250;251.


0.25-4 ppm gave good control 230.


32 kg/ha gave initial control of Chara vulgaris but it recovered and dominated after stabilization of the pond bottom 252.

0.25 ppm simazine as a single or double application gave effective and selective control of algae and suppressed Chara. Zooplankton communities were replaced by crustacea. Effective in water hardness of 16-140 ppm Ca and pH 6-9 with longest residual activity and efficacy in high pH, high hardness water. Dissolved oxygen decreased from 4 days after treatment but didn't drop to levels that were hazardous to fish or other aquatic life. Temporary increases in N and P levels occurred 14 days after treatment. Treated water had no effect on turf or woody perennials when used for irrigation 253 .

1.3 ppm simazine eliminated dense Chara vulgaris 254.


0.2 ppm controlled Chara in outside aquaria 243.


Thiobencarb at 2 kg/ha may have some action 255.

2 kg/ha gave control of Chara zeylanica in rice 223.


Provided control at 70 ppm 229.


Provided only transitory effects 236.


Eradication strategies:

Marron Ponds - Drain pond in spring. Apply 1 ml of hexazinone750 (Velpar DF) per 10 square metres of the sides and bottom of pond. Fill with water adding 4 mL simazine500 per 1 cubic metre (1,000 litres) of water to give 2 ppm simazine in the water. Test simazine concentration each month over summer and add simazine to bring the concentration up to 2 ppm (e.g. add 2 mL simazine500 per cubic metre of water in the pond to increase the concentration by 1 ppm). Don't release the water until the following spring to avoid damage that may be caused to vegetation by hexazinone. Marron in treated ponds need to be tested for herbicides residues to determine fitness for sale.

Herbicide resistance:

Biological Control:

Grass carp used in Argentina 256, India 257, Netherlands 258,Turkey 259, US 260-263, USSR 264;265.

Control with grass carp depend on fish density and other food species present 266;266.

Grass Carp consume about 370g Chara per day per fish 261.

Common Carp (Cyprinus carpio) used but often increase turbidity 267.

White amur (Ctenopharyngodon idella) fish used for control in the US 268-271, India 272.

Chara is a preferred food for white amur 243;273 and hybrid carp 274.

Redbelly tilapia (Tilapia zilli) may control Chara 275.

Blue tilapia (Tilapia aurea) may control Chara 276.

Goldfish, common carp, Tilapia mossambica and Tilapia aurea at 200 fishes/acre control filamentous algae and submerged weeds in ponds 212.

Apple snails Pomacea caniculata has potential as a control agent of Chara but have associated economic and health problems 227;277;278.

Azolla caroliniana may be useful in rice fields to reduce light to suppress Chara 279 but Azolla pinnata had no effect on Chara 280.

Related plants:

Plants of similar appearance:

Ceratophyllum has flowers.

Nitella species prefer acidic rather than alkaline conditions and have repeatedly branched stems, no odour, never encrusted with lime and are usually a darker green and more delicate than Chara. Antheridia are at the ends of short branches in Nitella and at the nodes below oogonia in Chara.

Parrots Feather (Myriophyllum aquaticum) has flowers.

Pondweeds (Potamogeton spp.) has flowers above the water surface.

Water Milfoil (Myriophyllum species) has flowers.

Widgeongrass (Ruppia spp.) has bisexual flowers and usually has alternate leaves.


Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

DiTomaso, J.M. and Healy, E.A. Aquatic and Riparian Weeds of the West (University of California, Oakland, ed. 1, 2003), pp. 1-442Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P

Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.


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