Featured Plants - Agalinis

Agalinis plant Agalinis Flower As you drive or walk through various natural communities in Florida beginning in late August and continuing through early November – particularly around mid-morning - you are likely to see pink to lavender flowers dotting the landscape, especially along roadsides, in flatwoods, savannas, sandhills, and marshes. These are most likely species of Agalinis. This group of plants belongs to the family Scrophulariaceae (or Orobanchaceae).

Agalinis is a genus of dicots, which are flowering plants with flower parts usually in fours or fives, branching veins on their leaves, and a unique stem anatomy. The flowers of Agalinis have five lobes, which are flattened or reflexed; the leaves are slender and either erect or spreading.

There are approximately 36 species of Agalinis in Eastern North America, 16 of which occur in Florida; all species of North American Agalinis are hemiparasites, which means that they derive some of their water and nutrition from other plants by a root structure known as a haustorium. Unlike obligate parasites, hemiparasites do not need a host to survive, but probably benefit from their parasitic relationship.

We have two species of Agalinis in Florida that are obligate (OBL) wetland plants: Agalinis linifolia and Agalinis maritima; both are quite distinctive in their appearance. The only other species that one may confuse with Agalinis maritima are Agalinis fasciculata and Agalinis purpurea. These two species can be distinguished from Agalinis maritima by their overall larger size, larger flowers, non-fleshy leaves, and their non-saline habitat.

Gerardia or False-Foxglove – Agalinis linifolia

Photos© by John Hays

This is the only species of Agalinis in North America that is perennial; it has an elongated rhizome that is easily removed intact from the soil. It is found in very wet habitats (often in standing water) around cypress domes, bogs, near streams in savannas or flatwoods, wet ditches, and pond margins. This species has large, deep pink flowers that are 2-3 cm long on long, erect flower stalks 1 to 2 cm long. The leaves are also erect, slender, dark green, and about 3-5 cm long. The plant is often large, up to 1.5 meters tall, and is often found leaning at a 10-20 degree angle with the stem remaining stiff. The flowers last but a day and produce a narrowly egg-shaped capsule with dark-brown seeds. It flowers mainly from mid-September through early October, but flowers somewhat earlier and longer in south Florida. Agalinis linifolia is scattered throughout the state, and like other species of Agalinis, it varies in local abundance from year to year. (Illustration)

Saltmarsh False-Foxglove, Agalinis maritima

Photos© by John Hays

In Florida this is the only species of Agalinis that inhabits saline habitats (as is the case throughout its range), and is restricted to shallow salt marshes, mangroves, and salt flats along the coast. In the Florida Keys, it can often be found inland, but is always associated with water. This annual species is much branched from the base or mid-stem, with the branches often arching widely upward. It has small (up to 3.0 cm long) slender, fleshy leaves and small (about 1 cm long) pink flowers on very short flower stalks (up to 7 mm), and the main flower stalk extends well above the side branches. The flowers last only a day and produce a rounded capsule with light-brown seeds. It flowers from late June through November in the northern part of the state, and nearly throughout the year in south Florida. Like most species of Agalinis, it has a sporadic occurrence, being abundant some years and absent other years. Locally, it can also be abundant or merely occasional. (Illustration)

For more information on species of Agalinis see:

Tobe, J.D., et al. 1998. Florida Wetland Plants: An Identification Manual. Florida Department of Environmental Protection, Wetlands Delineation and Evaluation Section, Tallahassee.

Godfrey, R.K., and J.W. Wooten. 1981. Aquatic and Wetland Plants of Southeastern United States: Dicotyledons. University of Georgia Press, Athens.

Line drawings are courtesy of Linny Heagy, and are copyrighted; no reproduction of these illustrations is allowed without the permission of the artist or John Hays.