Water pineapple, saw tooth, water aloe

General: Stratiotes aloides is a loosely rooted aquatic species with emergent and submerged growth forms (Cook and Urmi-König 1983; Erixon 1979).
Roots: Roots can be up to 180 cm long but are usually less.
Stem: Depressed conical stems with a complex but regular branching system that can resemble the household spider plant (Campbell 2009). Stem length: 10-18mm long (Cook and Urmi-König 1983)
Leaves: Serrated leaf edges distinguish it from similar looking aquatic plants in the Great Lakes (MNRF 2014). Submerged leaves can grow up to 60 cm (or rarely 110 cm long) and up to 1 cm wide with somewhat weak spines. Submerged leaves are thin, brittle and droop at an angle. Emergent leaves are thick, rigid, brittle, and dark green and are usually less than 40 cm long and 1-4 cm wide, with well-developed spines along leaf margins.
Flower/Fruit: Emergent form develops rosettes at the surface of the water (Cook and Urmi-König 1983).

The Lepidopteran larvae species Paraponyx stratiotata and Nymphula nymphaeata feed on fresh S. aloides tissue (Linhart, 1999). Veen et al. (2013) found that a variety of  vertebrate aquatic herbivores graze on S. aloides, reducing the biomass by 60%.

This species displays vegetative reproduction. Vegetative propagules are formed as axillary buds. When the bottom leaves of the rosette decay, these buds are released. On average 4.7 (±0.28 SE) buds are formed per mature rosette (n = 83) (Sarneel 2013). Buds have high capacity to disperse over long distances via water (84% of propagules re-sprouted, and 92% were still floating after 187 days) (Sarneel 2013).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

Stratiotes aloides has the potential to alter surrounding water chemistry, which may harm phytoplankton and other aquatic organisms (Ontario Ministry of Natural Resources 2009).  The exact mechanism has not been elucidated, but the likely cause is allelopathy (Mulderij et al. 2006). This species can also reduce phytoplankton and zooplankton biomass (Kurbatova and Yershov, 2018 and Kurbatova et al., 2019).

Stratiotes aloides has a moderate socio-economic impact in the Great Lakes.

Stratiotes aloides’s sharp leaves can cut skin (CommunityPress.ca 2009). Dense floating mats can hinder recreational activities, such as boating, angling, and swimming.

Stratiotes aloides has a moderate benefit to the Great Lakes.

S. aloides is high in flavonoids including luteolin apigenin, and chrysoeriol derivatives which can provide medicinal benefits (Gawlik-Dziki et al., 2020). This species is able to accumulate Strontium-90 from waterways and it has a higher affinity than other macrophytes (Kalinichenko et al., 2017) Additionally, it provides habitat for planktonic crustaceans, microcrustaceans, and terns (Strzalek and Koperski, 2009, Galowski et al., 2017, and Strzalek and Koperski, 2019).