Cardinal Flower

The form of Lobelia cardinalis sold as 'mini' or 'Kleine Form' is the compact trading variety of the North American cardinal flower, bred for the foreground. Instead of the tall emergent stems of the species, this one stays short and branches low, which is exactly what makes it a usable foreground plant rather than a background one.

New shoots appear along the base and can be cut and re-planted, so a small clump multiplies into a patch without much effort. The leaf colour depends on light and nutrient levels: bright green under moderate light, with a reddish tint appearing on the undersides when light and iron are generous. It is undemanding about water chemistry within a pH of 6 to 7.5.

Temperatures of 22 to 26 °C suit it well, though it tolerates a wider range in either direction. CO₂ is not required, but a planted tank with injected CO₂ and stable light keeps the growth denser and the leaves more uniform. It works in the foreground of a medium tank or in nano setups, where its slow rate of growth is an advantage rather than a limitation.