Indigofera caroliniana Mill.

Scientific Name and Growth Form

Indigofera caroliniana Mill. is a partially woody (suffruticose) herbaceous plant.

Height

It typically grows 0.5 to 1.2 meters tall, and can occasionally reach 2 meters in height.

Leaf Structure

Its leaves are 5 to 10 centimeters long, odd-pinnate, with a finely hairy rachis, and hold 9 to 15 obovate to oblanceolate leaflets.

Leaflet Dimensions

Each leaflet measures 1 to 2.5 centimeters long and 5 to 10 millimeters wide.

Leaflet Surface Features

Both leaflet surfaces are covered in fine minute strigillose hairs, with trichomes that attach at their midpoint, and leaflets are stipellate.

Inflorescence Characteristics

The inflorescences are slender axillary or terminal racemes, 6 to 20 centimeters long, and usually longer than the leaf they grow from.

Flower Arrangement

Flowers are loosely arranged, each borne on a roughly 1 millimeter pedicel with a small triangular bract.

Petal Features

Petals range in color from pinkish to yellowish-brown; the standard and keel petals are 5 to 6 millimeters long, while the wing petals are slightly shorter and adhere to the pouched keel.

Stamen Structure

The stamens are diadelphous, arranged in a 9+1 pattern, with the connective extending above the anthers.

Fruit and Seed Characteristics

The fruit is a short-stipitate, beaked legume that is 5 to 10 millimeters long, and holds one to three seeds.

Root Tubers

The root system of Indigofera caroliniana produces stem tubers that store non-structural carbohydrates.

Tuber Function

These tubers let the plant resprout after fire and persist through periods without fire.

Geographic Distribution

Indigofera caroliniana is distributed from eastern North Carolina south to South Florida, and west to southeastern Louisiana.

Habitat

It grows in longleaf pine sandhills, maritime forests, Florida scrub, and other types of sandy forests and woodlands.