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Species Name:    Conradina grandiflora
Common Name:     

   (Large-flowered Rosemary)


I.  TAXONOMY

Kingdom Phylum/Division: Class: Order: Family: Genus:
 Plantae  Magnoliophyta  Magnoliopsida  Lamiales Lamiaceae   Conradina
   
     

Large-flowered rosemary, Conradina grandiflora growing in a pine upland.  Photo courtesy of K. Hill, Smithsonian Marine Station.  


Close-up of Conradina grandiflora.  Photo courtesy of K. Hill, Smithsonian Marine Station. 

Species Name:
Conradina grandiflora
Small

Common Name:
Large-flowered rosemary, largeflower false rosemary, scrub mint.

Other Taxonomic Groupings:
Subkingdom : Tracheobionta
Subclass : Asteridae

Synonymy:
None.

Species Description:
A member of the mint family, Conradina grandiflora is a perennial, evergreen shrub endemic to Florida.  It grows to 1 - 1.5 m (3.3 - 5.0 feet) in height and has grayish bark along the woody portions of the stems.  Branches are typically arching or spreading in habit.  The aromatic leaves are needle-like and opposite, measuring 1 - 1.5 cm (0.4 - .6 inches) in length.  Upper parts of the leaves are dark green, shiny, and marked with small black dots.  The lower leaf surfaces may appear white or gray in color due to a dense growth of fine hairs along the stem and leaves (Nelson 1996). 

 


Blooming occurs throughout the year.  Stalked flowers appear on cymes in groups of 1 - 12.  Flowers are
two-lipped and large, measuring approximately 2 cm (0.8 inches) at the upper lip (Nelson 1996). 
There are 4 stamens that arch to the upper lip of the flower. 
Anthers lack horns (Wunderlin 1982; Small 1993), and the calyx is somewhat bent.  
Flower color is bright blue to lavender, with the lower lip flecked with tiny dark spots.  Fruits are small and nut-like, with a smooth skin and dark blue-black color (Nelson 1996).

Potentially Misidentified Species:
There are 5 species of Conradina that grow in the Southeastern U.S.  Conradina grandiflora is distinguished by its large flowers that are bourne on obvious stalks.


II.  HABITAT AND DISTRIBUTION 

Regional Occurrence:
Conradina grandiflora is endemic to the Atlantic Coastal Ridge in eastern Florida.  Its range extends from approximately Volusia County to Broward County (Nelson 1996).  It has likely been extirpated from Dade County (Kral 1983).

IRL Distribution:
Conradina grandiflora occurs in all IRL counties in coastal scrub areas, pine scrub, dunes, or sand hills where soil is deep and consists of fine sand (Kral 1983;  Nelson 1996).


III. LIFE HISTORY AND POPULATION BIOLOGY

Age, Size, Lifespan:
Large-flower rosemary reaches a height of approximately 1 - 1.5 m
(3.3 - 5.0 feet) and has leaves that measure approximately 1 - 1.5 cm (0.4 - .6 inches) in length (Nelson 1996). 

Abundance:
Conradina grandiflora is considered rare throughout its range; however, it is known to be common in some areas where its coastal scrub habitat has not been disturbed. 


V.  COMMUNITY ECOLOGY

Associated Species:
Conradina grandiflora is associated with plants typical of coastal scrub or pine scrub, including pines (Pinus spp.), Lyonia, hollies (Ilex Spp.), rosemary (Ceratiola sp.), cacti (Opunita spp.), and oaks (Quercus spp.) (Center for Plant Conservation, 2006).   

Habitats:
Large-flowered rosemary generally inhabits coastal backdunes, coastal scrub, maritime hammock, sand pine scrub, and sandhill areas from Volusia through Broward Counties. 


VI. SPECIAL STATUS

Special Status:
Conradina grandiflora has no Federal status as an imperiled species, though it is listed as Threatened in Florida, having been downlisted from its previous status as Endangered. 

It has has been assigned a global rank of G3 (FNAI 2006), which classifies it as rare and local, or restricted, throughout its range, with 21-100 known occurrences.  It is considered vulnerable to extinction due to habitat alteration or loss, with the primary threat being continued development of coastal scrub areas for commercial or residential uses. 

There are no active management plans for specific preservation of Conradina grandiflora, and Florida State Law considers endangered and threatened plants growing on privately owned lands as the property of the owner.   However, there are many incentives granted to Florida landowners, both large and small, who wish to conserve the rare and endangered plants and wildlife that occur on their lands.   


VII.  REFERENCES

Center for Plant Conservation.  2006.  Plant profile: Conradina grandiflora.  Accessed
     online at www.centerforplantconservation.org.  June 26, 2006.

Crook, R.W.  1996.  Conradina:  Interspecific and Intergeneric
     Relationships.  Tallahassee, FL.  Florida Division of Forestry,
     Statewide Endangered and Threatened plant Conservation program. 

FNAI.  2006.  Florida Natural Areas Inventory website.  Tracking list for Brevard
     County.  Accessed online at www.fnai.org.  June 26, 2006. 

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.   U.S. Dept. of Agriculture Forest Service
     Technical Publication R8-TP2, Vol. 1.

Nelson, G.  1996.  The Shrubs and Woody Vines of Florida.  Pineapple Press,
     Inc. Sarasota, FL.

Small, J.K.  1993.  Manual of the Southeastern Flora.  The University of North
     Carolina Press, Chapel Hill, NC.   

Taylor, W.T.  1992.  The Guide to Florida Wildflowers.  Taylor Publishing
     Co., Austin, TX.  320 pp. 

Wunderlin, R.P.  1982.  Guide to the Vascular Plants of Central Florida.  University
     Presses of Florida, University of Florida, Gainesville.  175 pp. 

 

Report by:  K. Hill, Smithsonian Marine Station
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Page last updated: June 26,  2006