Stenaria, Genus, spp., Multiple species,
- Genus
- Multiple species
Overview
Stenaria is a genus of about six species of perennial herbs and subshrubs in the madder family (Rubiaceae), native to North America from the central and southern United States into Mexico. Segregated from the genus Hedyotis, the plants form low clumps 6-18 inches (15-45 cm) tall with slender, wiry, four-angled stems and narrow, opposite leaves. From spring into autumn they carry small four-lobed tubular flowers about 0.2-0.5 inch (5-12 mm) across, white to pale pink or lavender, often with a darker or yellowish throat. The most widespread species, S. nigricans, is known as diamondflowers and grows on dry, rocky, often calcareous ground. Flowering is prolonged where soil moisture allows, and the slender stems form open, airy mounds. After flowering, small dry capsules split to release seed. Stenaria occupies prairies, limestone glades, rocky slopes, and open woodland on thin, well-drained soils. The genus tolerates heat, drought, and alkaline substrates but is short-lived on rich or poorly drained ground, and individual plants are often loose and sprawling rather than compact.
Native Range
Stenaria is native to North America, ranging through the central and southern United States, particularly Texas and the southern Great Plains, into northern and central Mexico. It grows on prairies, limestone glades, and dry rocky slopes, frequently on calcareous soils.Suggested Uses
Stenaria is used in rock gardens, gravel gardens, and native or prairie plantings on dry, alkaline soils. Its long bloom season suits pollinator and wildflower plantings in hot, sunny sites. It naturalizes in thin rocky soils where many perennials struggle.How to Identify
Appearance
Size & Dimensions
Height6" - 1'6"
Width/Spread8" - 1'6"
Bloom Information
Flowering extends from spring through autumn, roughly March to October, with the heaviest bloom after rainfall. Individual flowers are short-lived but are produced continuously over many weeks. In dry spells flowering pauses and resumes when moisture returns.
Detailed Descriptions
Flower Description
white to pale pink or lavenderFoliage Description
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
Stenaria grows in full sun to light shade on dry, sharply drained soils, including rocky, sandy, and calcareous ground. Water needs are low, and established plants tolerate heat and drought. Rich, fertile, or poorly drained soil shortens the plant life and produces weak, floppy growth. Soil pH in the neutral to alkaline range, roughly 6.5 to 8.0, suits the genus. Most species are hardy in about USDA zones 7-10. Plants self-sow where conditions suit and are easily raised from seed.Pruning
Pruning is light. Shearing the clumps after a flush of bloom encourages rebloom and tidies sprawling stems. Spent growth can be cut back in late winter before new shoots emerge.Container Growing
Suitable for container growing
Minimum container size: 1 gallons
