Taxon: Houstonia caerulea L.

Summary

Genus:

Houstonia

Family:

Rubiaceae

Subfamily:

Rubioideae

Tribe:

Spermacoceae

Nomen number:

19379

Place of publication:

Sp. pl. 1:105. 1753

Typification:

View in Linnean Typification Project

Verified:

08/14/2008 ARS Systematic Botanists.

Accessions:

5 (4 active, 0 available) in National Plant Germplasm System. (Map it)

Other conspecific taxa

Autonyms (not in current use), synonyms and invalid designations

Homotypic Synonym(s)
Hedyotis caerulea (L.) Hook.

Images (1 total. Click on image for more.)

Links

Forestry Images – from www.forestryimages.org

Conservation Status

Reference(s)

Aldén, B., S. Ryman, & M. Hjertson. 2012. Svensk Kulturväxtdatabas, SKUD (Swedish Cultivated and Utility Plants Database; online resource)
Andersson, L. et al. 2002. Relationships, circumscription, and biogeography of Arcytophyllum (Rubiaceae) based on evidence from cpDNA. Brittonia 54:40-49.
APHIS. Agricultural Risk Management System United States Department of Agriculture.
Church, S. A. & D. R. Taylor. 2005. Speciation and hybridization among Houstonia (Rubiaceae) species: the influence of polyploidy on reticulate evolution. Amer. J. Bot. 92:1372-1380.
Church, S. A. 2003. Molecular phylogenetics of Houstonia (Rubiaceae): descending aneuploidy and breeding system evolution in the radiation of the linage across North America. Molec. Phylogenet. Evol. 27:223-228.
Encke, F. et al. 1984. Zander: Handwörterbuch der Pflanzennamen, 13. Auflage
Huxley, A., ed. 1992. The new Royal Horticultural Society dictionary of gardening
Jones, G. N. & G. D. Fuller. 1955. Vascular plants of Illinois.
Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
Wofford, B. E. Database of Tennessee vascular plants (on-line resource).

Common names

Language	Name	seq	Citation
English	bluets	1	Huxley, A., ed. 1992. The new Royal Horticultural Society dictionary of gardening
English	Quaker-ladies	1	Huxley, A., ed. 1992. The new Royal Horticultural Society dictionary of gardening
Swedish	porslinsstjärna	2	Aldén, B., S. Ryman, & M. Hjertson. 2012. Svensk Kulturväxtdatabas, SKUD (Swedish Cultivated and Utility Plants Database; online resource)

Distribution

order_code	Status	Continent	Subcontinent	Country	State	Note	Reference
1	Native	Northern America	Eastern Canada	Canada	Nova Scotia		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Eastern Canada	Canada	Ontario	s.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Eastern Canada	Canada	Québec	s.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	North-Central U.S.A.	United States	Illinois		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	North-Central U.S.A.	United States	Iowa	e.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	North-Central U.S.A.	United States	Missouri	s.e.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	North-Central U.S.A.	United States	Wisconsin		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Connecticut		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Indiana		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Maine		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Massachusetts		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Michigan	s.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	New Hampshire		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	New Jersey		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	New York		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Ohio		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Pennsylvania		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Rhode Island		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	Vermont		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Northeastern U.S.A.	United States	West Virginia		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Alabama		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Arkansas		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Delaware		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Georgia		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Kentucky		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Louisiana	n.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Maryland		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Mississippi	n.e.	Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	North Carolina		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	South Carolina		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Tennessee		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
1	Native	Northern America	Southeastern U.S.A.	United States	Virginia		Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.
2	Cultivated					also cult.

Native
Northern America

EASTERN CANADA: Canada [Québec (s.), Nova Scotia, Ontario (s.)]
NORTHEASTERN U.S.A.: United States [Connecticut, Indiana, Maine, Massachusetts, Michigan (s.), New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia]
NORTH-CENTRAL U.S.A.: United States [Illinois, Iowa (e.), Missouri (s.e.), Wisconsin]
SOUTHEASTERN U.S.A.: United States [Alabama, Arkansas, Delaware, Georgia, Kentucky, Louisiana (n.), Maryland, Mississippi (n.e.), North Carolina, South Carolina, Tennessee, Virginia]

Cultivated (also cult.)

Reference(s)

Terrell, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Syst. Bot. Monogr. 48:23.

Economic Uses

Usage	Type	Note	Reference
Environmental	ornamental		Huxley, A., ed. 1992. The new Royal Horticultural Society dictionary of gardening
Environmental	ornamental		Encke, F. et al. 1984. Zander: Handwörterbuch der Pflanzennamen, 13. Auflage

Cite as: USDA, Agricultural Research Service, National Plant Germplasm System. 2026. Germplasm Resources Information Network (GRIN Taxonomy). National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: https://npgstest.ars-grin.gov/gringlobal/taxon/taxonomydetail?id=19379. Accessed 12 May 2026.