Azure Bluet
Houstonia caerulea
In the Carolinas and Georgia, found in forests, woodlands, openings, lawns, a wide variety of disturbed sites. Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition What its natural habitat tells you
Native to Louisiana. How scores work Is it native here?
Profile 88%
- Height
- 3–6 inches
- Spread
- 3–6 inches
- Light
- Dappled sunlight, Full sun, Partial shade
- Soil moisture
- Somewhat dry to moist
Space about 1 ft apart from its recorded spread, about 100 per 100 sq ft. Enter your bed size for a count
Will it fit your yard?
At a glance
- Life cycle
- Perennial
- Leaves
- Deciduous
- Fruiting season
- May to August
Not yet recorded · Bloom
Recorded in 10 Louisiana parishes.
Natural habitats
Places it grows wild. Not a planting requirement. Each habitat page lists the plants and wildlife also found there.
Forest or woodland where the source does not say how moist or dry.
Roadsides, fields and disturbed ground
Ground opened by people: roadsides, old fields, pastures, fencerows and lots.
Who uses this plant?
1CaterpillarsGenus host records with ranges including LA
Genus host records with ranges including LA · Houstonia
- Thyris maculataSpotted Thyris
13BeesSoutheastern regional records
Southeastern regional records · Houstonia
Individual names are not available yet.
Noori, Seltmann & Orr 2026, A curated and integrated dataset for exploring global bee-plant interactions (GloBI), Zenodo, CC BY 4.0
1Specialist beesPollen specialists
Pollen specialists · Houstonia
- Perdita pedernalensis
No records yet · Ants · Beetles · Flies · Adult butterflies / moths · Other wasps · Other insects
Plant details
- Family
- Rubiaceae
- Hardiness
- Zones 3a–8b
- Soil pH
- Acidic to neutral
- Flower color
- Blue, yellow or white
- Fruit begins
- May
- Fruit ends
- August
Safety has not been reviewed for this plant; check toxicity and thorns before planting.
Growing sources and scope
- Flower color · “Blue, yellow or white” · NC Extension Plant Toolbox
- Fruit begins · “May” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
- Fruit ends · “August” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
- Hardiness · “Zones 3a–8b” · NC Extension Plant Toolbox
- Height · “3–6 inches” · NC Extension Plant Toolbox
- Leaves · “Deciduous” · NC Extension Plant Toolbox
- Life cycle · “Perennial” · NC Extension Plant Toolbox
- Light · “Dappled sunlight (shade through upper canopy all day); Full sun (6 or more hours of direct sunlight a day); Partial shade (direct sunlight only part of the day, 2-6 hours)” · NC Extension Plant Toolbox
- Soil · “Moist; Occasionally dry” · NC Extension Plant Toolbox
- Soil pH · “Acidic to neutral” · NC Extension Plant Toolbox
- Spread · “3–6 inches” · NC Extension Plant Toolbox
Also known as
Quaker Ladies
Conservation status
| Louisiana rank | S4 |
|---|---|
| Global rank | G5 |
| LA status | Not verified |
| Federal status | Not verified |
Will it fit your yard?
Check this plant against your county, sun and soil moisture. Conditions are checked in your browser.
Sources
- Weakley, Flora of the Southeastern United States (2025), South Central edition
- USDA PLANTS
- Vascular Plants of North Carolina (NC Natural Heritage Program)
- NatureServe Explorer
- Louisiana occurrence source
- Shropshire & Tallamy 2025, Lepidoptera of North America north of Mexico, ZooKeys 1261 (ODbL)
- Noori, Seltmann & Orr 2026, A curated and integrated dataset for exploring global bee-plant interactions (GloBI), Zenodo, CC BY 4.0
- Smith, Bachelder, Russell, Morales, Mosher & Seltmann 2024, Bee-Specialization-Modeling v0.6.1 (specialist host table compiled from J. Fowler's pollen specialist bee lists), Zenodo, CC BY 4.0
- Hurlbert, Olsen, Sawyer & Winner 2021, Avian Diet Database, Scientific Data 8: 260 (CC0)
- Narango, Tallamy & Shropshire 2020, Few keystone plant genera support the majority of Lepidoptera species, Nature Communications

