Houstonia caerulea (Bluets)

Houstonia caerulea L.

Hedyotis caerulea (L.) Hook.

Houstonia caerulea L. var. faxonorum Pease & A.H. Moore

Bluets, quaker ladies, azure bluet

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Asteridae	A large class that encompasses asters
Order	Gentianales	Gentians, coffee, gardenias, frangipani, many others
Family	Rubiaceae	Coffee, madder, and bedstraw family
Genus	Houstonia	Named for English botanist Dr. William Houston
Species	caerulea	“Blue,” from the same root as the English word “cerulean”

About plant names...

Bluets are natives of central and eastern North America. The name “Quaker ladies” may be a reference to their white bonnets.

Identification: Azure bluets, as you can see from the photos at right, aren’t necessarily azure. Most often pale blue, they range from white to a darker shade of blue. Bluets are diminutive, less than 8" (20 cm) in height. They produce dense clusters of flowers, each about ⅜" (1 cm) across, with four petals and a yellow center. I see them most often nestled in small brilliant patches in lawns.

Online References:

Houstonia caerulea on Missouriplants.com

Houstonia caerulea on www.jeffpippen.com

Houstonia caerulea at Illinois Wildflowers

Houstonia caerulea at the Lady Bird Johnson Wildflower Center

Houstonia caerulea on the Connecticut Botanical Society's Connecticut wildflowers site

Houstonia caerulea at the University of Wisconsin's Robert W. Freckmann Herbarium

Houstonia caerulea on Southeastern Flora, the Southeastern U.S. Plant Identification Resource

5/15/2010 · Garden in the Woods, Framingham, Massachusetts
≈ 8 × 5" (19 × 13 cm)

5/11/2013 · Townsend Wildlife Management Area, Townsend, Massachusetts
≈ 4½ × 6" (12 × 15 cm)

Houstonia caerulea description by Thomas H. Kent, last updated 25 May 2020.

5/15/2010 · Garden in the Woods, Framingham, Massachusetts
≈ 6 × 4" (15 × 10 cm)

5/30/2014 · Townsend Wildlife Management Area, Townsend, Massachusetts
≈ 9 × 6" (22 × 15 cm)

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts
≈ 17 × 12" (44 × 29 cm)

The flowers are diminutive, at less than 1/4" across, but the leaves, usually hidden, are much smaller. · 5/15/2016 · Mt. Watatic, Ashby, Massachusetts

4/21/2010 · Tom and Susan’s, Pepperell, Massachusetts
≈ 8 × 5" (19 × 13 cm)

5/20/2012 · J. Harry Rich State Forest, Groton, Massachusetts
≈ 6 × 4½" (15 × 11 cm)

Range: Zones 3-8:

About this map...