CPC National Collection Plant Profile

Dicerandra immaculata

c. 1991 Steve Shirah

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CPC National Collection Plant Profile

Dicerandra immaculata

Common Names: 
Lakela's mint, Olga's mint
Growth Habit: 
CPC Number: 


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Dicerandra immaculataenlarge
Photographer: c. 1991 Steve Shirah

Dicerandra immaculataenlarge
Photographer: c. 1991 Steve Shirah

Dicerandra immaculata is Fully Sponsored
Primary custodian for this plant in the CPC National Collection of Endangered Plants is: 
S.K. Maddox contributed to this Plant Profile.

Dicerandra immaculata

Lakela's mint is a small, fragrant, perennial shrub that reaches a height of 50 cm. It was listed in 1985 as federally threatened, and faces a high risk of extinction because so much of its habitat has been lost and its populations are so fragmented. This species is known from only one wild population. (USFWS 1999)

Dicerandra immaculata can be differentiated from others in the Dicerandra genus by its lavender-rose colored flower that has no spots on it. When grown in open sun, its growth is bushy; in the shade it becomes lax. The primary branches arise from a stout, deep, woody-branched taproot. As it grows it forms small mats or domes of ascending to spreading or sprawling branches. The main leaves are horizontal or pointing upwards, while those with flower clusters sometimes point downward. The leaves are 2 to 3 cm long, 2 to 4 mm wide, smooth, flattened, subsessile, narrowly rounded at the apical end (USFWS 1999). The flowers which appear primarily September through November, are formed in whorls of 1 to 3 flowers in the leaf axils. The tiny flowers are less than 0.8 inches long, rose-purple with no spots or lines. The corolla is 2-lipped with rounded lobes, and the tube is smoothly curved, not sharply bent. The anthers have tiny spurs, and the stamens extend beyond the flower. Both the stems and leaves have a strong mint odor (Chafin 2000).

Distribution & Occurrence

State Range
State Range of  Dicerandra immaculata
  Lakela's mint, a Florida endemic, is restricted to sand scrub habitats found on ancient dunes formed along former ocean shorelines in Indian River and St. Lucie Counties. These soils consist of highly drained, infertile sands (USFWS 1991). Dicerandra immaculata has been observed growing in both yellow and white sands, and does best in light shade or clearings in the scrub. These bare areas are probably created by wind action and fires (USFWS 1999).

Other species found in this coastal scrub include sand pine, sand live, myrtle and live oaks, scrub hickory, cabbage palm, hog plum, and tough bumelia along with some epiphytic species (USFWS 1991).

  The range of D. immaculata is very small, being confined to a area one-half mile wide by three miles long in southern Indian River and northern St. Lucie Counties. D. immaculata was introduced on Hobe Sound National Wildlife Refuge in Martin County in 1991 and 1992. The plants at the Hobe Sound National Wildlife Refuge's two introduction sites are doing well, and both have new seedlings. St Lucie County has considered purchase of two sites, one which would protect the largest remaining population of Lakela's mint, and one which would provide the first protected site within its historic range (USFWS 1999).

Number Left
  Currently, Lakela's mint is known from a single native population that is scattered across 9 unprotected sites. There is one planted population that is protected (FNAI 2000).

This species also occurs at two sites in Hobe Sound National Wildlife Refuge, where it was introduced in 1991 and 1992. (USFWS 1999)


Global Rank:  
Guide to Global Ranks
Federal Status:  
Guide to Federal Status
Recovery Plan:  

State/Area Protection
  State/Area Rank Status Date  
  Florida S1 LE 4/1/1998  

Conservation, Ecology & Research

Ecological Relationships
  Known as a "gap" species, D. immaculata thrives in open sunlight and becomes weak when shaded by other plant species (USFWS 1999)

It is protected from insect herbivory by the essential oils found in its tissue (McCormick et al. 1993). Lakela's mint is, however, adversely affected by mildew. Mildew grows on the nectary glands, potentially causing destruction of fruits and seeds before they are able to be dispersed (USFWS 1999).

This species reproduces only through seeds, and insects are needed for successful pollination and seed production. The flowers of this species have spurred anthers, which require insects to trigger them to release and disperse their pollen. Unfortunately, the pollinators for this species are not known. (USFWS 1987).

Seed dispersal is extremely limited. Seed from flowering plants in one of the introduced populations was dispersed a maximum of 2 meters away from its maternal plant. (Race 1994)

  Commercial and residential development.
Sand mining.
Fungal disease.
Loss of habitat.
(USFWS 1999)

Current Research Summary
  The introduction of this species at Hobe Sound NWR was possible because of propagation and transplant work carried out by Bok Tower Gardens. (Race 1994)

Current Management Summary
  There are two sites currently being managed at Hobe Sound NWR in Martin County. The two sites, introduced in 1991 and 1992, are both still reproductively active. St. Lucie County is working to purchase a parcel of land in the northern part of the county, which would possibly provide the first protected site within the species known historic range (USFWS 1999).

Research Management Needs
  Purchase and protect privately owned sites.
Control off-road-vehicle traffic.
Eradicate exotic pest plants.
Use occasional fire to open up habitat.
(FNAI 2000)

Ex Situ Needs
  Conserve germ plasm.
Maintain ex situ collection.


Books (Single Authors)

Coile, N.C. 2000. Notes on Florida's Regulated Plant Index (Rule 5B-40), Botany Contribution 38. Gainesville, Florida: Florida Dept. of Agriculture and Consumer Services, Division of Plant Industry.

FNAI. 2000. Field Guide to the Rare Plants and Animals of Florida online. Florida Natural Areas Inventory.

Huck, R.B. 1987. Systematics and evolution of Dicerandra (Labiatae) (Phanerogamarum monographiae XIX). Stuttgart, Germany: Gebruder Borntraeger Verlagsbuchhand-lung.

Wunderlin, R.P. 1998. Guide to the vascular plants of Florida. Gainesville, Florida: University Press of Florida. 806p.

Books (Sections)

Dolan, R.W.; Menges, E.S. 1998. Chapter 9: Genetic Variation in Nolina brittoniana and Dicerandra Species. In: Menges, E.S.; Dolan, R.W.; Gordon, D.R.; Evans, E.K.; Yahr, R., editors. Demography, ecology, and preserve design for endemic plants of the Lake Wales Ridge, Florida: Final report to The Nature Conservancy's ecosystem research program.

Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC.

Electronic Sources

(2001). Herbarium Type Specimens. [Web site] State University System of Florida Publication of Archival Library & Museum Materials. http://sid.fcla.edu/mrsid/herb/. Accessed: 2002.

(2002). Atlas of Florida Vascular Plants. [Web site] University of South Florida Institute for Systematic Botany. http://www.plantatlas.usf.edu/isb/default.htm. Accessed: 2008.

Denton, S. (2001). Photo Library of Native and Naturalized Plants of Florida. Biological Research Associates. http://www.biolresearch.com/Plants/index.php?id=C. Accessed: 2002.

Journal Articles

1984. Endangered Species. AABGA Newsletter. pp. 4.

Corin, C.W. 1988. Approved Recovery Plans. Endangered Species Technical Bulletin. 13, 4: 3-4.

Eisner, T.; McCormick, K.D.; Sakaino, M.; Eisner, M.; Smedley, S.R.; Aneshansley, D.J.; Deyrup, M.; Myers, R.L.; Meinwald, J. 1990. Chemical defense of a rare mint plant. Chemoecology. 1, 1: 30-37.

Kral, R.D. 1982. Some notes on Dicerandra (Lamiaceae). Sida. 9, 3: 238-262.

Lakela, O. 1963. Dicerandra immaculata Lakela, sp. nov. (Labiatiae). Sida. 1, 3: 1184-185.

McCormick, K.D.; Deyrup, M.A.; Menges, E.S.; Wallace, S.R.; Meinwald, J.; Eisner, T. 1993. Relevance Of Chemistry To Conservation Of Isolated Populations: The Case Of Volatile Leaf Components Of Dicerandra Mints. Proceedings of the National Academy of Sciences of the United States of America. 90, 16: 7701-7705.

McDonald, D.B.; Hamrick, J.L. 1996. Genetic variation in some plants of Florida scrub. American Journal of Botany. 83, 1: 21-27.

Miller, Harvey A. 1993. A new species of Dicerandra (Lamiaceae) from Florida. Phytologia. 75, 3: 185-89.

Shinners, L.H. 1962. Synopsis of Dicerandra (Labiatae). Sida. 1, 2: 89-91.

USFWS. 1984. Endangered Species Technical Bulletin. 9, 8: 5.

USFWS. 1984. Proposed Endangered Status for Dicerandra immaculata (Lakela's Mint). Federal Register. 49, 142: 29632-29635.

USFWS. 1984. Protection. Endangered Species Technical Bulletin. 9, 8: 3-6.

USFWS. 1984. Regional Briefs. Endangered Species Technical Bulletin. 9, 7: 2, 6.

USFWS. 1984. Regional Briefs--Region 4. Endangered Species Technical Bulletin. 9, 12: 11.

USFWS. 1985. Determination of Endangered Status for Dicerandra immaculata (Lakela's Mint). Federal Register. 50, 94: 20212-20215.

USFWS. 1985. Florida Plant. Endangered Species Technical Bulletin. 10, 6: 7.

USFWS. 2001. A newsletter dedicated to sharing information about the Florida scrub ecosystem. U.S. Fish & Wildlife Service: Saving Our Scrub. 2, 3: 8.

Wallace, S.R. 1991. Central Florida Scrub: Trying to Save the Pieces. Endangered Species UPDATE. 8, 1: 60-62.

Newspaper Articles

Mitchell, C. 1998 Sunday, February 1. Rare Private Plant May Get Some Public Ownership. Press Journal (North St. Lucie); A. 15.

Shabecoff, Philip. 1988 Tuesday, December 6. Survey Finds Native Plants in Imminent Peril. The New York Times; New York, NY. Science Times.


1984. AABGA Newsletter: Endangered Species. American Association of Botanic Gardens and Arboretum.

Austin, D.E.; Nauman, C.E.; Tatje, B.E. 1980. Final report: endangered and threatened plant species survey in southern Florida and the National Key Deer and Great White Heron National Wildlife Refuges, Monroe County, Florida. Atlanta, Georgia: U.S. Fish and Wildlife Service.

Kral, R. 1983. A report on some rare, threatened or endangered forest related vascular plants of the south. Atlanta, GA: U.S. Forest Service. p.718. USFS technical publication R8-TP2, . Vol. 1.

Kral, R. 1983. A report on some rare, threatened, or endangered forest-related vascular plants of the South. Athens, GA: U.S. Dept. of Agriculture Forest Service. p.1305. U.S. Dept. of Agriculture Forest Service Technical.

Race, T. 1994. Establishment of a new population of Dicerandra immaculata at the Hobe Sound National Wildlife Refuge in Florida. Vero Beach, Florida: Unpublished report prepared for the U.S. Fish and Wildlife Service; Jacksonville, Florida. On file at U.S. Fish and Wildlife Service, South Florida Ecosystem Office.

Robinson, A.F., Jr. 1981. Status review of Dicerandra immaculata (Lakela's mint). Jacksonville, Florida: Unpublished report prepared for U.S. Fish and Wildlife Service.

Stout, I.J. 1996. Annual Report-Proposal to Study Lupinus aridorum, Warea amplexifolia, and Dicerandra immaculata. Tallahassee, Florida: Florida Division of Forestry: Statewide Endangered and Threatened Plant Conservation Program.

Stout, Jack I.; Black, Dameron; Woiak, Sandy. 1998. Final Report-Proposal to Study Lupinus aridorum, Warea amplexifolia and Dicerandra immaculata. Tallahassee, Florida: Florida Division of Forestry: Statewide Endangered and Threatened Plant Conservation Program.

USFWS. 1987. Recovery Plan for Three Florida Mints. Atlanta, GA: Service, U.S. Fish & Wildlife. p.21.

USFWS. 1999. South Florida Multi-species Recovery Plan. Atlanta, GA: U.S. Fish and Wildlife Service, Southeast Region.

  This profile was updated on 3/4/2010
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