Egeria (plant) particularly in Europe, fast-growing, adaptable plants such as "Egeria" can spread quickly and cause major damage to native plants and wildlife. Egeria (plant) Egeria is a genus of three species of aquatic plants in the family Hydrocharitaceae described as a genus in 1849. native to warm-temperate South America. The genus was formerly included in the related genus "Elodea", from which it differs in having the leaves in whorls of four or more, not three, and in having more conspicuous flowers with larger (particularly broader) petals. "Egeria" is found in many temperate and subtropical regions throughout the world as an introduced,
Viola (plant) head-like, narrowed or often beaked. The flowers have a superior ovary with one cell, which has three placentae, containing many ovules. "Viola" are most often spring blooming with chasmogamous flowers with well-developed petals pollinated by insects. Many species also produce self-pollinated cleistogamous flowers in summer and autumn that do not open and lack petals. In some species the showy chasmogamous flowers are infertile (e.g.,"Viola papilionacea"). After flowering, fruit capsules are produced that split open by way of three valves. On drying, the capsules may eject seeds with considerable force to distances of several meters. The nutlike seeds have straight embryos,