The latter is not too different from the standard form, though. One of the most striking characteristics of the Bacopa caroliniana is the lemon scent the leaves emit when crushed.
The basis of the ovate leaves encloses the stem entirely. This stem plant doesn't grow very fast, but needs lots and lots of light, at least 0.5 watts per litre. It grows slightly better when fertilised with micro and macronutrients, this is relatively unimportant, though, as well as a fertilisation with CO2.
Under intensive light and with low levels of nitrate, this Bacopa assumes a bronze to brownish hue, when the phosphate level is low, it turns slightly pink. It can also be kept emersed in temperate climates throughout the warm season, e.g. on the edge of a pond, where it grows pretty fast, with a creeping, ground-covering habit, a hairy stalk and characteristic purple flowers.
Propagating is very easy, just make cuttings of the top or lateral shoots and replant. It also forms runners from the stem bases that can be simply cut off and replanted.
The stems have the best effect in an aquascape when planted in a terracing or stepped group in the middle- or (in larger aquaria) the foreground of the tank. This special geometry provides groups of other plants with a resting point to be based on.