''Houstonia'' (bluet) is a genus of plants in the family

Rubiaceae The Rubiaceae are a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules a ...

. Many species were formerly classified, along with other genera since segregated elsewhere, in a more inclusive genus ''

Hedyotis ''Hedyotis'' (starviolet) is a genus of flowering plants in the family Rubiaceae. Many species of this genus such as ''Hedyotis biflora, H. corymbosa'' and ''H. diffusa'' are well known medicinal plants. ''Hedyotis'' is native to tropical and su ...

''. Bluets are often small and delicate. For example, ''H. rosea'' may grow only one inch tall. Some species are single stemmed and others have multiple stems in bunches. Flowers are blue, purple, lavender, white, or rose, often with shades of one color present in an individual population. Flowers have 4

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s, colloquially denominated "petals", a salverform corolla with 4 lobes, and an inferior ovary. Some species exhibit heterostyly. The fruit is an often roughly cordate capsule enclosing many seeds and which usually dehisces via a suture across its apex. ''Houstonia'' consists of 20 species native to North America. Another 5 species are classified in the genus '' Stenaria''; ''Houstonia'' without ''Stenaria'' is paraphyletic. Close relatives of the genus are '' Oldenlandia microtheca'' and, more distantly, '' Arcytophyllum''. Its members superficially resembles species of the genus ''

Myosotis ''Myosotis'' ( ) is a genus of flowering plants in the family Boraginaceae. The name comes from the Ancient Greek "mouse's ear", which the foliage is thought to resemble. In the northern hemisphere they are colloquially known as forget-me-no ...

'' (Forget-me-nots), but are distinguished from the latter by having only 4

s (petals) instead of 5.

Species

Species accepted as of May 2014 are:Kew World Checklist of Selected Plant Families
/ref> # '' Houstonia acerosa'' (A.Gray) Benth. & Hook.f.: Chihuahua, Coahuila, Nuevo León,

Tamaulipas Tamaulipas (), officially the Free and Sovereign State of Tamaulipas ( es, Estado Libre y Soberano de Tamaulipas), is a state in the northeast region of Mexico; one of the 31 states which, along with Mexico City, comprise the 32 Federal Entiti ...

, and San Luis Potosí and

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

# '' Houstonia biloba'' Raf. # '' Houstonia caerulea'' L. (azure bluet): eastern

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and eastern United States # '' Houstonia canadensis'' Willd. ex Roem. & Schult. (Canadian summer bluet):

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

and

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

and eastern United States # '' Houstonia cervantesii'' Terrell # '' Houstonia chlorantha'' Bertol. # '' Houstonia correllii'' (W.H.Lewis) Terrell (Correll's bluet):

, United States # '' Houstonia croftiae'' Britton & Rusby (Croft's bluet):

, United States # '' Houstonia humifusa'' (Engelm. ex A.Gray) A.Gray (matted bluet):

, Oklahoma, and

, United States # '' Houstonia longifolia'' Gaertn. (longleaf summer bluet): eastern and central United States and central

# '' Houstonia micrantha'' (Shinners) Terrell (southern bluet): central and southeastern United States # '' Houstonia nuttalliana'' Fosberg # '' Houstonia ochroleuca'' Raf. # ''

Houstonia ouachitana ''Houstonia ouachitana'', the Ouachita bluet, is a species of plants in the Rubiaceae, coffee family. It is endemic to the Ouachita Mountains of Arkansas and Oklahoma. It is an herb up to 20 cm tall, with lanceloate basal leaves and narrowly ...

'' (E.B.Sm.) Terrell (Ouachita bluet):

Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the O ...

and Oklahoma, United States # '' Houstonia palmeri'' A.Gray: Coahuila and Nuevo León # '' Houstonia parviflora'' Holz. ex Greenm. (Greenman's bluet):

, United States # '' Houstonia procumbens'' (J.F.Gmel.) Standl. (roundleaf bluet):

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...

Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...

Alabama (We dare defend our rights) , anthem = "Alabama" , image_map = Alabama in United States.svg , seat = Montgomery , LargestCity = Huntsville , LargestCounty = Baldwin County , LargestMetro = Greater Birmingham , area_total_km2 = 135,765 ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

, and

South Carolina )'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...

, United States # '' Houstonia prostata'' Brandegee # '' Houstonia purpurea'' L. (Venus' pride): eastern and central United States # '' Houstonia pusilla'' Schöpf (tiny bluet): central and southeastern

and

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

, United States # '' Houstonia reticulata'' Raf. # '' Houstonia rosea'' (Raf.) Terrell (rose bluet): south-central United States # '' Houstonia rubra'' Cav. (red bluet): northern and central

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

as far south as Puebla and

, and

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, United States # ''

Houstonia serpyllifolia ''Houstonia serpyllifolia'', commonly called thymeleaf bluet, creeping bluet, mountain bluet, Appalachian bluet or Michaux's bluets is a species of plant in the coffee family (Rubiaceae). It is native to the eastern United States, where it is fou ...

'' Michx. (creeping, mountain, thymeleaft, and Appalachian bluet):

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...

from

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

, United States # '' Houstonia sharpii '' Terrell:

Hidalgo Hidalgo may refer to: People * Hidalgo (nobility), members of the Spanish nobility * Hidalgo (surname) Places Mexico * Hidalgo (state), in central Mexico * Hidalgo, Coahuila, a town in the north Mexican state of Coahuila * Hidalgo, Nuevo Le� ...

and

Veracruz Veracruz (), formally Veracruz de Ignacio de la Llave (), officially the Free and Sovereign State of Veracruz de Ignacio de la Llave ( es, Estado Libre y Soberano de Veracruz de Ignacio de la Llave), is one of the 31 states which, along with Me ...

# '' Houstonia spellenbergii'' (G.L.Nesom & Vorobik) Terrell: Chihuahua # '' Houstonia subviscosa'' (C.Wright ex A.Gray) A.Gray (nodding bluet):

, United States # '' Houstonia teretifolia '' Terrell: Coahuila # '' Houstonia wrightii'' A.Gray (pygmy bluet):

, and

, United States and

References

{{Taxonbar, from=Q9005036 Rubiaceae genera Flora of North America