Index / Search / Houstonia caerulea
§1 Plant
Houstonia caerulea L.
vernacular azure bluet — species · Rubiaceae
§2Habit & range
Habit and range
- Growth habit
- Forb/herb
- Duration
- Perennial
- Group
- Dicot
- Family
- Rubiaceae Juss.
- Genus
- Houstonia
§2a
Native status, by region
- CAN Canada Native
- L48 Lower 48 States Native
- SPM St. Pierre & Miquelon Introduced
§2b
County-level range
· 733 counties across 27 states/territories§3Cultivation
No cultivation specs.
USDA has not characterised this taxon. Roughly four out of five plants in the database lack the detailed cultivation record present here — typically because they have not been the focus of NRCS Plant Materials work. Range and distribution data are unaffected.
§4Counties, by state
Recorded in 733 counties across 27 states/territories.
Alabama view state ↗ 13 N ▾
Arkansas view state ↗ 23 N ▾
- Ashley 05003
- Bradley 05011
- Clark 05019
- Clay 05021
- Cleburne 05023
- Cleveland 05025
- Conway 05029
- Dallas 05039
- Drew 05043
- Faulkner 05045
- Garland 05051
- Grant 05053
- Hot Spring 05059
- Jefferson 05069
- Lincoln 05079
- Lonoke 05085
- Pike 05109
- Pulaski 05119
- Saline 05125
- Stone 05137
- Union 05139
- Van Buren 05141
- White 05145
Delaware view state ↗ 2 N ▾
District of Columbia view state ↗ 1 N ▾
Georgia view state ↗ 41 N ▾
- Baldwin 13009
- Bartow 13015
- Bibb 13021
- Bulloch 13031
- Carroll 13045
- Chattooga 13055
- Cherokee 13057
- Clarke 13059
- Cobb 13067
- Columbia 13073
- Coweta 13077
- Dawson 13085
- DeKalb 13089
- Elbert 13105
- Floyd 13115
- Fulton 13121
- Gilmer 13123
- Hall 13139
- Haralson 13143
- Harris 13145
- Jackson 13157
- Jasper 13159
- Johnson 13167
- Lee 13177
- Madison 13195
- Meriwether 13199
- Morgan 13211
- Murray 13213
- Oglethorpe 13221
- Paulding 13223
- Pike 13231
- Rabun 13241
- Richmond 13245
- Rockdale 13247
- Spalding 13255
- Stephens 13257
- Toombs 13279
- Towns 13281
- Turner 13287
- Upson 13293
- Walker 13295
Illinois view state ↗ 15 N ▾
Indiana view state ↗ 35 N ▾
- Brown 18013
- Cass 18017
- Clark 18019
- Clay 18021
- Crawford 18025
- Daviess 18027
- Dearborn 18029
- Floyd 18043
- Franklin 18047
- Fulton 18049
- Greene 18055
- Harrison 18061
- Jackson 18071
- Jasper 18073
- Jefferson 18077
- Kosciusko 18085
- Lake 18089
- LaPorte 18091
- Lawrence 18093
- Marshall 18099
- Montgomery 18107
- Newton 18111
- Owen 18119
- Porter 18127
- Pulaski 18131
- Ripley 18137
- Scott 18143
- Spencer 18147
- St. Joseph 18141
- Starke 18149
- Switzerland 18155
- Vigo 18167
- Washington 18175
- Wayne 18177
- White 18181
Kentucky view state ↗ 73 N ▾
- Adair 21001
- Allen 21003
- Barren 21009
- Bath 21011
- Bell 21013
- Boyd 21019
- Breckinridge 21027
- Bullitt 21029
- Caldwell 21033
- Calloway 21035
- Campbell 21037
- Carter 21043
- Casey 21045
- Christian 21047
- Clark 21049
- Clay 21051
- Edmonson 21061
- Elliott 21063
- Estill 21065
- Fayette 21067
- Fleming 21069
- Floyd 21071
- Franklin 21073
- Garrard 21079
- Grayson 21085
- Greenup 21089
- Hardin 21093
- Harlan 21095
- Harrison 21097
- Hart 21099
- Henderson 21101
- Henry 21103
- Hickman 21105
- Hopkins 21107
- Jackson 21109
- Jefferson 21111
- Jessamine 21113
- Johnson 21115
- Knox 21121
- Larue 21123
- Laurel 21125
- Lee 21129
- Leslie 21131
- Letcher 21133
- Lewis 21135
- Lincoln 21137
- Logan 21141
- Lyon 21143
- Madison 21151
- Marion 21155
- Marshall 21157
- McCreary 21147
- McLean 21149
- Meade 21163
- Menifee 21165
- Metcalfe 21169
- Montgomery 21173
- Morgan 21175
- Nelson 21179
- Oldham 21185
- Powell 21197
- Pulaski 21199
- Robertson 21201
- Rockcastle 21203
- Rowan 21205
- Russell 21207
- Scott 21209
- Todd 21219
- Trigg 21221
- Warren 21227
- Wayne 21231
- Whitley 21235
- Wolfe 21237
Louisiana view state ↗ 7 N ▾
Maine view state ↗ 15 N ▾
Massachusetts view state ↗ 14 N ▾
Michigan view state ↗ 3 N ▾
Mississippi view state ↗ 1 N ▾
Missouri view state ↗ 22 N ▾
- Butler 29023
- Cape Girardeau 29031
- Carter 29035
- Clay 29047
- Dent 29065
- Douglas 29067
- Dunklin 29069
- Howell 29091
- Iron 29093
- Jackson 29095
- Madison 29123
- New Madrid 29143
- Pemiscot 29155
- Phelps 29161
- Reynolds 29179
- Ripley 29181
- Shannon 29203
- St. Clair 29185
- St. Francois 29187
- Ste. Genevieve 29186
- Texas 29215
- Wayne 29223
New Hampshire view state ↗ 10 N ▾
New Jersey view state ↗ 15 N ▾
New York view state ↗ 35 N ▾
- Albany 36001
- Bronx 36005
- Cattaraugus 36009
- Chemung 36015
- Columbia 36021
- Delaware 36025
- Dutchess 36027
- Essex 36031
- Fulton 36035
- Greene 36039
- Hamilton 36041
- Herkimer 36043
- Jefferson 36045
- Lewis 36049
- Nassau 36059
- Niagara 36063
- Oneida 36065
- Ontario 36069
- Orange 36071
- Oswego 36075
- Putnam 36079
- Rensselaer 36083
- Richmond 36085
- Rockland 36087
- Saratoga 36091
- St. Lawrence 36089
- Suffolk 36103
- Sullivan 36105
- Tioga 36107
- Tompkins 36109
- Ulster 36111
- Warren 36113
- Washington 36115
- Wayne 36117
- Westchester 36119
North Carolina view state ↗ 69 N ▾
- Alamance 37001
- Alexander 37003
- Alleghany 37005
- Ashe 37009
- Beaufort 37013
- Bladen 37017
- Buncombe 37021
- Cabarrus 37025
- Caswell 37033
- Catawba 37035
- Chatham 37037
- Cherokee 37039
- Chowan 37041
- Clay 37043
- Cleveland 37045
- Craven 37049
- Cumberland 37051
- Davidson 37057
- Davie 37059
- Durham 37063
- Edgecombe 37065
- Forsyth 37067
- Franklin 37069
- Gaston 37071
- Gates 37073
- Graham 37075
- Granville 37077
- Guilford 37081
- Halifax 37083
- Henderson 37089
- Hertford 37091
- Hyde 37095
- Iredell 37097
- Jackson 37099
- Johnston 37101
- Jones 37103
- Lee 37105
- Lincoln 37109
- Macon 37113
- Madison 37115
- Martin 37117
- Mecklenburg 37119
- Montgomery 37123
- Moore 37125
- Nash 37127
- Northampton 37131
- Orange 37135
- Pasquotank 37139
- Pender 37141
- Person 37145
- Pitt 37147
- Polk 37149
- Randolph 37151
- Richmond 37153
- Robeson 37155
- Rockingham 37157
- Rowan 37159
- Rutherford 37161
- Sampson 37163
- Stanly 37167
- Stokes 37169
- Surry 37171
- Tyrrell 37177
- Union 37179
- Vance 37181
- Wake 37183
- Warren 37185
- Washington 37187
- Yancey 37199
Ohio view state ↗ 61 N ▾
- Adams 39001
- Ashland 39005
- Ashtabula 39007
- Athens 39009
- Belmont 39013
- Brown 39015
- Carroll 39019
- Champaign 39021
- Clark 39023
- Clermont 39025
- Clinton 39027
- Columbiana 39029
- Coshocton 39031
- Crawford 39033
- Cuyahoga 39035
- Delaware 39041
- Erie 39043
- Fairfield 39045
- Franklin 39049
- Gallia 39053
- Geauga 39055
- Greene 39057
- Guernsey 39059
- Hamilton 39061
- Harrison 39067
- Highland 39071
- Hocking 39073
- Holmes 39075
- Huron 39077
- Jackson 39079
- Jefferson 39081
- Knox 39083
- Lake 39085
- Lawrence 39087
- Licking 39089
- Lorain 39093
- Mahoning 39099
- Medina 39103
- Meigs 39105
- Monroe 39111
- Morgan 39115
- Morrow 39117
- Muskingum 39119
- Noble 39121
- Ottawa 39123
- Perry 39127
- Pickaway 39129
- Pike 39131
- Portage 39133
- Preble 39135
- Richland 39139
- Ross 39141
- Scioto 39145
- Seneca 39147
- Stark 39151
- Summit 39153
- Trumbull 39155
- Tuscarawas 39157
- Vinton 39163
- Washington 39167
- Wayne 39169
Pennsylvania view state ↗ 63 N ▾
- Adams 42001
- Allegheny 42003
- Armstrong 42005
- Beaver 42007
- Bedford 42009
- Berks 42011
- Blair 42013
- Bucks 42017
- Butler 42019
- Cambria 42021
- Cameron 42023
- Carbon 42025
- Centre 42027
- Chester 42029
- Clarion 42031
- Clearfield 42033
- Clinton 42035
- Columbia 42037
- Crawford 42039
- Cumberland 42041
- Dauphin 42043
- Delaware 42045
- Elk 42047
- Fayette 42051
- Forest 42053
- Franklin 42055
- Fulton 42057
- Greene 42059
- Huntingdon 42061
- Indiana 42063
- Jefferson 42065
- Juniata 42067
- Lackawanna 42069
- Lancaster 42071
- Lawrence 42073
- Lebanon 42075
- Lehigh 42077
- Luzerne 42079
- Lycoming 42081
- McKean 42083
- Mercer 42085
- Mifflin 42087
- Monroe 42089
- Montgomery 42091
- Northampton 42095
- Northumberland 42097
- Perry 42099
- Philadelphia 42101
- Pike 42103
- Schuylkill 42107
- Snyder 42109
- Somerset 42111
- Sullivan 42113
- Susquehanna 42115
- Tioga 42117
- Union 42119
- Venango 42121
- Warren 42123
- Washington 42125
- Wayne 42127
- Westmoreland 42129
- Wyoming 42131
- York 42133
Rhode Island view state ↗ 5 N ▾
South Carolina view state ↗ 24 N ▾
- Abbeville 45001
- Anderson 45007
- Charleston 45019
- Cherokee 45021
- Darlington 45031
- Dillon 45033
- Dorchester 45035
- Edgefield 45037
- Fairfield 45039
- Florence 45041
- Greenville 45045
- Kershaw 45055
- Lancaster 45057
- Lee 45061
- Lexington 45063
- Marion 45067
- McCormick 45065
- Pickens 45077
- Richland 45079
- Saluda 45081
- Spartanburg 45083
- Union 45087
- Williamsburg 45089
- York 45091
Tennessee view state ↗ 61 N ▾
- Anderson 47001
- Benton 47005
- Bledsoe 47007
- Blount 47009
- Bradley 47011
- Campbell 47013
- Cannon 47015
- Carter 47019
- Cheatham 47021
- Clay 47027
- Coffee 47031
- Cumberland 47035
- Davidson 47037
- Decatur 47039
- DeKalb 47041
- Dickson 47043
- Fentress 47049
- Franklin 47051
- Grainger 47057
- Grundy 47061
- Hamblen 47063
- Hamilton 47065
- Hardin 47071
- Hawkins 47073
- Haywood 47075
- Henry 47079
- Hickman 47081
- Knox 47093
- Lawrence 47099
- Lewis 47101
- Lincoln 47103
- Loudon 47105
- Macon 47111
- Madison 47113
- Marion 47115
- McMinn 47107
- Meigs 47121
- Monroe 47123
- Montgomery 47125
- Moore 47127
- Morgan 47129
- Overton 47133
- Pickett 47137
- Polk 47139
- Putnam 47141
- Roane 47145
- Robertson 47147
- Rutherford 47149
- Scott 47151
- Sequatchie 47153
- Sevier 47155
- Stewart 47161
- Sumner 47165
- Unicoi 47171
- Van Buren 47175
- Warren 47177
- Washington 47179
- Wayne 47181
- Weakley 47183
- White 47185
- Williamson 47187
Vermont view state ↗ 12 N ▾
Virginia view state ↗ 92 N ▾
- Accomack 51001
- Albemarle 51003
- Alleghany 51005
- Amelia 51007
- Amherst 51009
- Appomattox 51011
- Arlington 51013
- Augusta 51015
- Bath 51017
- Bedford 51019
- Bland 51021
- Botetourt 51023
- Brunswick 51025
- Buckingham 51029
- Campbell 51031
- Caroline 51033
- Carroll 51035
- Charles City 51036
- Charlotte 51037
- Chesapeake (city) 51550
- Chesterfield 51041
- Craig 51045
- Culpeper 51047
- Cumberland 51049
- Dickenson 51051
- Dinwiddie 51053
- Essex 51057
- Fairfax 51059
- Fauquier 51061
- Floyd 51063
- Fluvanna 51065
- Franklin 51067
- Frederick 51069
- Giles 51071
- Gloucester 51073
- Goochland 51075
- Grayson 51077
- Greene 51079
- Greensville 51081
- Halifax 51083
- Hampton (city) 51650
- Hanover 51085
- Henrico 51087
- Henry 51089
- Highland 51091
- Isle of Wight 51093
- James City 51095
- King and Queen 51097
- King George 51099
- King William 51101
- Lancaster 51103
- Loudoun 51107
- Louisa 51109
- Lunenburg 51111
- Madison 51113
- Mathews 51115
- Mecklenburg 51117
- Middlesex 51119
- Montgomery 51121
- Nelson 51125
- New Kent 51127
- Newport News (city) 51700
- Northampton 51131
- Northumberland 51133
- Nottoway 51135
- Orange 51137
- Page 51139
- Patrick 51141
- Powhatan 51145
- Prince Edward 51147
- Prince George 51149
- Prince William 51153
- Pulaski 51155
- Rappahannock 51157
- Richmond 51159
- Roanoke 51161
- Rockingham 51165
- Scott 51169
- Shenandoah 51171
- Southampton 51175
- Spotsylvania 51177
- Stafford 51179
- Suffolk (city) 51800
- Surry 51181
- Sussex 51183
- Tazewell 51185
- Virginia Beach (city) 51810
- Warren 51187
- Washington 51191
- Westmoreland 51193
- Wise 51195
- York 51199
West Virginia view state ↗ 13 N ▾
§5Sources & provenance
USDA PLANTS
Symbol, taxonomy, distribution, cultivation specs, native status. Public domain.
plants.usda.gov/HOCA4 ↗GBIF Backbone
Canonical taxonomic identity, synonym resolution, cross-refs. CC0.
gbif.org/species/5338866 ↗Record version
Cached and built locally. Source version on this record:
usda-plants-mt-2026-05-26
fetched 2026-05-26T20:46:58Z