Mountain Bluet / Center For Plant Conservation
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Plant Profile

Mountain Bluet (Houstonia purpurea var. montana)

This shot shows Spreading avens from above. The plant forms low-growing loose tufts 10-15 centimeters tall, with purple flowers. Photo Credit: Nora Murdock
  • Global Rank: T2 - Imperiled
  • Legal Status: Federally Endangered
  • Family: Rubiaceae
  • State: NC, TN
  • Nature Serve ID: 155857
  • Lifeform: Forb/herb
  • Date Inducted in National Collection: 03/05/1993

Roan Mountain bluet is a rare endemic found on a few mountains in the Southern Appalachians. A member of the coffee family (Rubiaceae), Roan Mountain bluet produces heterostylus flowers (two different length styles). This species is a compact clump forming perennial herb and produces flat top clusters of one to four deep red-purple flowers from May to September. The flower color helps distinguish H. purpurea var. montana from the more common H. purpurea var. purpurea with flowers of blue-purple to white. The US Fish and Wildlife Service recognize Roan Mountain bluet as a restricted variety of Hedyotis purpurea. While its morphological distinctness is clear, the taxonomic position is disputed (US Fish and Wildlife Service, 1996). Roan Mountain bluet is also known as Houstonia montana. Noted by Asa Gray in 1841 as a dwarf form and described by J.K. Small in 1903 as Houstonia montana, taxonomic differences have ensued over the generic placement, altering between Hedyotis and Houstonia, and recognition at the varietal level or designation of full species rank. See Terrell (1959), Yelton (1974) and Terrell (1978) for more taxonomic information. The current opinion places Roan Mountain bluet as Houstonia montana (US Fish and Wildlife 1996, Weakley in preparation 2008).

Where is Mountain Bluet (Houstonia purpurea var. montana) located in the wild?


Roan Mountain bluet grows at high elevation (above 4,200 ft) in the shallow soils and crevices of cliffs and outcrops and on thin rocky soils of grassy balds. This species is associated acidic soils and with Fraser fir (Abies fraseri) and red spruce (Picea rubens) forests. Roan Mountain bluet is typically found with five co-occurring species, Saxifraga michauxii, Athyrium filix-femina spp. asplenioides, Paronychia argycoma, Heuchera villosa and Carex misera, seventy-five percent of the time (US Fish and Wildlife 1996).


Roan Mountain bluet is found on scattered mountains along the NC and TN boarder.

States & Provinces:

Mountain Bluet can be found in North Carolina, Tennessee

Which CPC Partners conserve Mountain Bluet (Houstonia purpurea var. montana)?

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

  • 09/16/2020
  • Genetic Research

Kelsey Glennon (George Washington University) is studying the genetic variation and potential hybridization of Roan Mountain bluet (2008).

Nature Serve Biotics
  • 05/02/2017

A narrow endemic of a few very high peaks in northwestern North Carolina and adjacent Tennessee. Fewer than ten small populations are known. A very limited amount of potential habitat exists and most is subject to intensive recreational uses such as ski resort development, trampling by hikers, and climbing/rock scrambling. Populations could also be lost to woody plant succession.

Michael Kunz
  • 01/01/2010

Trampling by hiker and climbers. Development. Succession and other vegetation changes. Possibly air pollution and exotic insects change the surrounding spruce-fir forests.

Michael Kunz
  • 01/01/2010

Roan Mountain bluet is known from twelve populations with all but one subpopulation located in NC (Euliss et al. 2007).

Michael Kunz
  • 01/01/2010

Dalenia S. Medford, a graduate student at East Tennessee State University, completed a Masters Thesis on this species in August 2001. (Medford 2001) This study investigated population level variation in this and another rare species across a time span of 150 years. Euliss et al. studied the growth of Houstonia montana in contrasting habitats (2007). And Kelsey Glennon (George Washington University) is studying the genetic variation and potential hybridization of Roan Mountain bluet (2008).

Michael Kunz
  • 01/01/2010

Survey suitable habitat for additional populations. Protect populations on private land. Reducing visitor access to sites to limit trampling.

Michael Kunz
  • 01/01/2010

The red spruce forests controlled by the U.S. Forest Service are regularly sprayed with an insecticide, Lindane. A study is needed to determine if there are short-term and/or long-term effects of this practice on this species (Morgan 1980). There is also a continued need to limit visitor access to reduce trampling and protect the species habitat as well as a need to continue searching for additional populations. Detailed research on demographics, biotic and abiotic requirements, pollination biology, seed bank dynamics, metapopulation dynamics and the role of changing natural conditions in population viability should also be done.

Michael Kunz
  • 01/01/2010

Maintain and expand ex situ (whole plant and seed) holdings of Roan Mountain bluet, as well as understanding germination and propagation protocol for future research. There is also a need for public education to raise awareness of the species and reduce the negative recreational effects.


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Taxon Houstonia purpurea var. montana
Authority (Small) Terrell
Family Rubiaceae
CPC Number 2175
ITIS 196213
Duration Perennial
Common Names mountain bluet | Roan Mountain bluet | Venus' pride | Roan Mountain bluet
Associated Scientific Names Hedyotis purpurea var. montana | Houstonia purpurea var. montana | Houstonia montana
Distribution Roan Mountain bluet is found on scattered mountains along the NC and TN boarder.
State Rank
State State Rank
North Carolina S2
Tennessee S1
Ecological Relationships

Common Name Name in Text Association Type Source InteractionID
Bumble bees Bumble bees Floral Visitor Link
Rove beetles Staphylinid beetles Floral Visitor Link
Syrphid flies Syrphid flies Floral Visitor Link
Ants Floral Visitor Link

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