About Bacopa caroliniana (Walter) B.L.Rob.
Bacopa caroliniana (Walter) B.L.Rob. is a perennial creeping herb. Its leaves are succulent, relatively thick, oblanceolate, and arranged oppositely on the stem. Crushed leaves give off a lemon scent. The five-petaled flowers are blue. This plant reaches a height of 50–100 cm (20–39 in). If given the opportunity, it will grow above the water, developing similar but waxy leaves. It can occasionally flower even when fully underwater, though these underwater flowers quickly rot. Emersed (above-water) flowers do not produce seeds on their own and require cross pollination. Bacopa caroliniana commonly grows in marshy areas of the southern United States. Its ability to grow in water makes it a popular aquarium plant, and it can tolerate slightly brackish conditions. It propagates easily through cuttings and grows readily in aquariums. Leaf color changes based on light availability: leaves turn bronze or almost entirely red under high light levels. In the wild, it grows in bogs or in semi-submersed conditions, and adapts well to full flooding and submersion. It can be grown in or alongside ponds in warmer regions, or in shallow dishes or as a house plant when kept sufficiently damp, growing year-round in suitable conditions. It is frost tender, but usually regrows from the roots if frost damages its above-ground growth. It prefers light shade when grown outside of aquariums. In aquariums, it needs good lighting for strong growth, but can survive in even fairly low light. It favors a clean, nutrient-rich environment.