Lindernia Dubia is a moderately common marsh plant from the eastern United States to South America. Relatively new to aquarists, it joins several others of its genus in the hobby. Unlike Lindernia sp. ‘India’ and L. parviflora, this is a species with some additional size and heft. Rather than a fore or mid ground accent, it is an interesting substitute for plants like Bacopa caroliniana. Steady but not weedy growth and stems that almost always remain straight lend L. dubia to a variety of aquascaping uses and perhaps even Dutch aquariums.
In its natural habitat of pond edges and shallow water, L. dubia is always found in full sun; this should always be kept in mind when giving it a new home. Conditions typical of high-tech planted aquariums such as strong lighting, abundant carbon dioxide, and regular and balanced fertilization foster healthy and surprisingly verdant growth. No nutrient sensitivities are apparent. It is unknown how well this species will do in lower light conditions, so the reader is invited to find out if he or she is so inclined.
L. dubia can easily be confused with the related Gratiola species G. virginiana and G. neglecta, the latter of which does not perform well in aquariums (the author is not aware of G. virginiana having been evaluated). A key distinguishing feature of L. dubia is its square stems. Additionally, its flowers are a pale lilac as opposed to white in the other two. Rare in some seasons, it can be very common in others. If none can be found locally, it may be possible to obtain a few stems from other hobbyists.