Flower:

Loose raceme on the emergent portion of a hollow stem, rising up to 12 inches above the water surface. Flowers are pale blue to white, ½ to ¾ inch long, the petals forming a long tube with 3 lower lobes of similar size and 2 smaller upper lobes. The lower lobes are hairy at the base. 5 short lance-like sepals surround the base of the tube, set upon a short stalk.

Leaves and stems:

Leaves are usually submerged, linear and flattened with a blunt tip, hollow, 1 to 2 inches long, forming a basal rosette of arching blades. Stem is hollow and unbranched.

Fruit:

The fruit is a nodding, conical barrel-like capsule about ½ inch long with the remnant of the style attached at the tip.

Notes:

A decidedly northern species, Lobelia dortmanna is relatively common in the cool, clear tanin-stained lakes of the Arrowhead region. While only the emergent 10-12 inches is visible, the hollow, underwater portion of the flower stalk can be up to 3 feet long! Flowers can even bloom and set seed under water. When not in bloom, the hollow, blunt-tipped leaves distinguish Water Lobelia from other aquatic species.