Lobelia dortmanna in cultivation, June 2025

This member of the Campanulaceae family thrives in aquatic environments, favouring cool, oligotrophic, and slightly acidic waters. In France, it is critically endangered, having only ever been present in a few isolated locations.

Where it still occurs, it stands as a remnant of a distant past—the last glaciation. At that time, the French landscape resembled that of present-day northern Scandinavia. Following the warming period that began some 12,000 years ago, the species retreated to a handful of clear lakes. It is for this reason that it is known as a "glacial relict." Today, it remains common in the boreal zones of Eurasia and North America, where the climate suits its physiological needs.

This specimen, cultivated for several years, originates from its southernmost site in France, in the Landes region. There, it grows submerged near the lake shores. It shuns close proximity to other plants that deprive it of light, and dislikes silt even more. Its flower stalks rise vertically, piercing the water’s surface. The young blossoms display a faint bluish hue, which fades as the flower matures.