Agalinis tenuifolia (Vahl) Raf.

Nomenclature and Stem Characteristics

Agalinis tenuifolia (Vahl) Raf. grows 20 to 60 centimeters tall, with a slender stem that branches in a paniculate pattern. Its simple, opposite leaves measure 20 to 50 millimeters long and only 1 to 3.5 millimeters wide.

Flower Pedicel Features

Flowers grow on pedicels that are 10 to 20 millimeters long. Each flower is bilaterally symmetrical, with five fused petals 10 to 15 millimeters long that form a corolla tube, plus four stamens.

Fruit Characteristics

The fruit is a round dry capsule 3 to 7 millimeters long that splits open when it is ripe.

Broad Distribution Range

This species is widely distributed across eastern Canada and the United States, though its local distribution may be spotty. It has been recorded in the U.S. states of Alabama, Arkansas, Colorado, Connecticut, Washington, D.C., Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Mississippi, North Carolina, North Dakota, Nebraska, New Hampshire, New Jersey, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Virginia, Vermont, Wisconsin, West Virginia, and Wyoming, as well as the Canadian provinces of Manitoba, New Brunswick, Ontario, and Quebec.

Conservation Status

Agalinis tenuifolia is listed as a species of special concern in the U.S. state of Rhode Island.

Virginia Habitat

In Virginia, it grows in habitats including dry woods and barrens, and is found particularly in open disturbed areas such as old fields.

Michigan Habitat

In Michigan, by contrast, it grows in moist or even marshy ground, including along river banks.

Habitat Threats

This species’ survival in an area depends on having appropriate habitat; it can be eliminated from an area by development, changes in land use, or competition with invasive species.

Parasitic Trait

Like other species in the genus Agalinis, A. tenuifolia is hemiparasitic on a variety of host plants, especially graminoids. It uses haustoria to connect its roots to the roots of its host plants, but it also has green tissues and carries out photosynthesis on its own.