Lobelias are easily identified by their flowers with the two-lipped corolla and the tube split on the upper side. The upper lip consists of two often smaller and erect lobes and the lower lip of three spreading lobes. Most lobelias are blue but there are some species with mauve, white or pink flowers.

Lobelia aquaemontis is a small perennial, and it forms soft, bushy mounds, about 150 mm high and wide. The thin stems and divided leaves give the plants a delicate, lacy feel. Overall, the plants are pale green but close up one notices that the undersides of the leaves and many of the stems have a deep red tinge. It grows fast during the warm summer months and flowers continuously from spring, through summer to autumn. The single, pale blue flowers are proudly displayed at the tips of the thin stems.