Sisyrinchium pruinosum
roadside blue-eyed grass
South-central United States and northern Mexico
Overview
Sisyrinchium pruinosum is a clump-forming perennial in the iris family and, despite its common name, not a true grass, growing 6-16 inches (15-40 cm) tall in tufts of narrow, flattened, blue-green leaves 1-3 mm wide. The slender, winged flowering stems, often coated with a powdery waxy bloom that gives the species its name, rise just above the foliage. In spring it bears small, six-pointed star flowers 0.5-0.75 inch (12-18 mm) wide, violet-blue to purple with a bright yellow eye at the center and a darker ring around the throat. Each flower lasts a single day, opening in morning sun and closing by afternoon, but a clump produces them in steady succession. Small round capsules follow, ripening to release dark seeds. Bees and other small insects visit the flowers for pollen. It grows on prairies, open woodlands, roadsides, and disturbed grassy ground across Texas and neighboring parts of the south-central United States and Mexico. Plants go dormant or semi-dormant in summer heat and revive with autumn rains. The clumping grassy form and one-day blue flowers make it easy to recognize among spring wildflowers.
Native Range
Native to the south-central United States and northern Mexico, centered on Texas and reaching into Oklahoma, New Mexico, and neighboring states. It grows on prairies, rocky open woods, roadsides, and disturbed grassland. Its range follows the southern Great Plains and Edwards Plateau.Suggested Uses
Sisyrinchium pruinosum is used in native, meadow, and rock garden plantings, along path edges, and scattered through short-grass lawns and prairies. Its grassy clumps and spring flowers suit the front of borders and gravelly beds. It naturalizes well on open, sunny ground where it can reseed.How to Identify
Appearance
Size & Dimensions
Height6" - 1'4"
Width/Spread6" - 1'
Reaches mature size in approximately 1 years
Bloom Information
Flowering comes in spring, mainly March to May, as the cool-season foliage reaches full growth. Each violet-blue flower opens for a single morning, but a clump opens new flowers daily over several weeks. Bloom fades as summer heat sends the plant toward dormancy.
Detailed Descriptions
Flower Description
violet-blue with a yellow eyeFoliage Description
blue-greenGrowing Conditions
Sun Requirements
Requires 5-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Sisyrinchium pruinosum grows in full sun to light shade on well-drained sandy, loamy, or rocky soil, tolerating both lean and average ground. It needs moisture through the cool growing season but tolerates summer drought once it slows or goes dormant. The plant is hardy in USDA zones 7-9 and self-sows where the ground is open. Clumps can be lifted and divided in autumn or early spring to renew vigor and expand a planting. Overly rich, wet soil shortens its life and encourages rot, so moderate fertility suits it. It asks little beyond a sunny spot and decent drainage.Pruning
No real pruning is needed for this small clumping perennial. Tattered foliage can be trimmed as the plant goes summer-dormant. Seed capsules may be left to ripen so the plant can self-sow and fill in over time.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons