Oeceoclades maculata, A Fast-Spreading Newcomer to Florida
The tropical species ground orchid, Oeceoclades maculata (syn. Eulophidium maculatum), was first discovered in Florida by Dr. Robert Grimm while leading a group of botany students through Matheson Hammock (Dade County) in 1974 (Hammer, 1981). Since then, this species has rapidly colonized virtually all of the hardwood forests throughout Dade County, including Everglades National Park, and is now also known from Broward, Collier, Lee, Palm Beach, and Monroe counties. It has formed extensive colonies on North Key Largo and occurs within Long Key and Bahia Honda State Recreation Areas in the Florida Keys. Plants taken to Gainesville in 1988 by William Stern, Professor, University of Florida, escaped cultivation and have survived the cold winters of northern Florida's Alachua County (Stern, 1988).
While the genus Oeceoclades evolved in equatorial Africa, ground orchid is the only species in the genus that is indigenous to both Africa and South America. The early European explorer William Burchell collected the type specimen of ground orchid at "Porto-Real" in Brazil on March 24, 1829. There are also Florida native orchids with an African distribution. Eulophia alta and Palystachya concreta are both indigenous to Africa as well as the New World, and there is speculation that Eulophia alta was brought to the New World by African slaves who used the basal corms in folk medicine. There is even speculation that the newly-arrived ground orchids underwent a natural expansion of range northward from South America as a result of gradual climatic change (Huntley, 1991). If it did, indeed, arrive in Florida naturally, should it be accepted as a new addition to our native flora? The possibility exists, of course, that it spread into Florida habitats from cultivated plants and, under such conditions, it should be deemed an invasive exotic. However it got here, it is probably here to stay.
Ground orchid is a terrestrial species with mottled, two-tone green, longitudinally-keeled leaves that superficially resemble members of the genus Sansevieria (Agavaceae). Erect flower spikes appear from the base of the pseudobulbs, usually in September and October in southern Florida. Flowers are about 1/2 inch and bear pink blotches. The disturbance caused by rainfall effectively pollinates the flowers (Gonzalez-Diaz and Ackerman, 1988) and seed pods are readily set. This is a species of shady hardwood hammocks and tree orchards where it thrives in leaf litter, not actually rooted into soil. Ground orchid is currently listed* in the Exotic Pest Plant Council's Category I list of Florida's most invasive species. To help document the spread of this rapidly dispersing orchid in Florida, it is requested that resource managers note its occurrence and report any findings to Roger L. Hammer**, Resource Management Supervisor, Natural Areas Management, 22200 Southwest 137 Avenue, Miami, FL 33170, or call (305) 257-0904.
--Roger L. Hammer, Resource Management Supervisor, Metro-Dade Parks Department, Natural Areas Management.
Gonzalez-Diaz, N. and J. D. Ackerman. 1988. Pollination and fruit set in the orchid Oeceoclades maculata. Lindleyana 3: 150-155.
Hammer, R. 1981. Finding new orchids: A contribution to the Orchidaceae of Florida. Fairchild Tropical Garden Bulletin 36: 16-18.
Huntley, B. 1991. How plants respond to climate change; migration rated, individualism and the consequences for plant communities. Ann. Bot. (London) 67: 15-22.
Stern, W. 1988. The long-distance dispersal of Oeceoclades maculata. American Orchid Society Bulletin 57 (9): 960-971.
1. Identification and Biology of Nonnative Plants in Florida’s Natural Areas – Second Edition, by K.A. Langeland, H.M. Cherry, et al. University of Florida-IFAS Publication # SP 257. 2008.
2. Strangers in Paradise, Impact and Management of Nonindigenous Species in Florida, Chapter 2: Florida’s Invasion by Nonindigenous Plants: History, Screening, and Regulation, by D.R. Gordon and K.P. Thomas, pp. 21-37. Island Press, Washington, DC, 1997.