Stenaria nigricans

Species Native to Missouri
Common Name: diamondflowers 
Type: Herbaceous perennial
Family: Rubiaceae
Native Range: Central United States
Zone: 4 to 8
Height: 0.50 to 1.50 feet
Spread: 0.50 to 1.50 feet
Bloom Time: April to October
Bloom Description: Pale lilac to white
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Flower: Showy

Culture

Easily grown in moist, well-drained soils in full sun to part shade. Tolerates close to full shade. Avoid full sun locations in hot summer climates where morning sun with afternoon shade is probably best. Performs well in sandy or calcareous soils.

Noteworthy Characteristics

Stenaria nigricans, commonly known by a large number of common names including diamond flowers, narrow-leaved bluet, fine leaf bluet, glade bluet, and prairie bluet, is a woody-based perennial that typically sends few to numerous, slender, ascending stems to 6-12” tall, but infrequently to as much as 2-3’ tall, particularly in areas with consistently moist soils. It is native to a variety of habitats including dry rocky prairies, rocky open woods, grassy hillsides, rocky stream banks, escarpments of limestone bluffs and glades, and along roadsides from Michigan to Colorado south to Florida, Texas and northern Mexico. In Missouri, it is found throughout the Ozark region, mostly in limestone, dolomite or calcium-rich soils.

Each plant features opposite pairs of very narrow, linear to linear-lanceolate leaves (to 1 1/4” long and 1/8” wide), each leaf having a single center vein, rolled margins and a pointed tip. Tiny flowers (to 1/4” across) bloom in showy crowded clusters (axillary cymes) at the stem ends from April into summer, sometimes with sporadic continued bloom into fall. Each flower features (a) a green calyx, (b) a pale lilac to white tubular corolla with 4 backward-curving lobes, and (c) 4 protruding stamens and a single protruding style. Flowers are followed by tiny, non-ornamental, ovacapsular seeded fruits.

Notwithstanding its currently accepted scientific name of Stenaria nigricans, this plant was formerly listed by the now synonymous names of Houstonia nigricans and Hedyotis nigricans.

Genus name comes from the Greek word stenos meaning narrow in reference to leaf shape.

Specific epithet from Latin means black in reference to the leaves turning black when dry.

Problems

No serious insect or disease problems.

Garden Uses

Rock gardens where it will thrive in full sun locations in gritty limestone soils. Wildflower gardens. Cottage gardens. Beds and borders.