Lindernia dubia

Lindernia dubia originates from the east of the USA, where it is moderately spread. It has been introduced into other regions of the world by human activities, and it is also found in parts of Central Europe in some places. In nature, L. dubia is an annual plant, growing in shallow waters and forming a part of pioneer plant vegetation on muddy ground.
In the aquarium hobby, several species of the genus Lindernia are already known, however, L. dubia is relatively new; in Europe it seems to be still a rather unknown plant for aquaria. Differently from L. sp. 'India', L. parviflora and L. rotundifolia, L. dubia is a more sizable plant with more optical weight. It is a very suitable accent plant for the fore- and middleground, providing an interesting alternative to plants like Bacopa caroliniana. Its steady and yet rather slow growth and its upright shoots make it a suitable plant for several types of plant layouts, and maybe even for Dutch-style aquaria.

L. dubia is always found in full sun in nature - on the edges of ponds and in shallow water; please keep this in mind when placing it in your layout. "High tech" planted tanks with typically intensive light, high concentrations of CO2 and a steady, controlled fertilisation provide L. dubia with all its needs for heathly growth and a surprisingly intensive green hue. It is not very susceptible towards nutrient deficiencies. It is still not known how L. dubia reacts to lower light.

In its North-American habitat, Lindernia dubia is easily confused with the Gratiola species that are also found there, namely G. virginiana and G. neglecta; however, at least the latter does not do well in the aquarium. A key characteristic for differentiation is the square cross section of the stem of L. dubia. Moreover, the flowers of this species have a pale purple colour, in contrast to the white flowers of both Gratiola species. L. dubia is scarce during some years, during others it can be found in large numbers.