Hottonia is an aquatic plant that consists of just two species, Hottonia palustris and Hottonia inflata. The latter variety lives in slow moving streams, swamps, and marshes of the eastern and southern U.S. while H. palustris can be found in European and Asian wetlands. They belong to the primrose, or Primulaceae, family of plants, and listed as either endangered or threatened in most of their native areas. The more common names for these plants are Featherfoil and Water Violet.
Hottonia inflata is often grown for its soft, feathery foliage rather than its flowers. It has unusual thick stalks which produce tiny white flowers in summer. While the roots and lower parts of this plant grow in the water, the top 2 to 6 inches (5 to 15 cm) grow above the water. This makes these aquatic plants an attractive choice for water gardens.
Hottonia palustris looks much like its American cousin, but has thicker leaf growth much in the shape of snowflakes, and intensely bright purple flowers. It also grows much taller, often reaching 20 inches (51 cm) or more. This entire plant is submerged in water and often thrives in water gardens where insects such as dragonflies and beetles hide in its dense growth. They are a beautiful addition to aquariums where the graceful movement of these plants can be appreciated.
While beautiful, these types of plants can be difficult to grow. They must have strong, direct light and cool water to live and require the addition of nitrates and phosphorus as well. Without these, the plants will turn yellow or darken and will eventually die. Lack of very bright light will also kill these plants because they cannot tolerate even a small amount of shade. When conditions are optimal, these plants are fast growers that require pruning to keep them under control.
While Hottonia can be grown successfully from seed, the germination rate seems to vary widely. Seeds do not germinate as well in standing water as they do when planted in moist soil. Seedlings will live directly in the water, however, and often float on the surface for weeks. Transplants root well in spring or summer; cuttings will often root when immediately placed in water or planted in mud.
Hottonia palustris is a popular alternative medicine and said to improve confidence and assertiveness when used regularly. It is thought to aid those who are shy and withdrawn and help them to be more outgoing and positive. This flower remedy is taken in tablet, powder, or tincture form, and can be found in many health food stores and online.