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Plant Profile

Florida Semaphore Cactus (Consolea corallicola)

This is a large species of prickly pear cactus with a distinct trunk and a cluster of pads at the top. Photo Credit: Meghan Fellows

Global Rank: G1 - Critically Imperiled
Legal Status: Federally Endangered
Family: Cactaceae
State: FL
Nature Serve ID: 128380
Lifeform: Shrub
Categories of Interest: Cacti/Succulents
Date Inducted in National Collection: 03/08/1989

Description:

The Semaphore cactus is an erect, trunk-forming prickly-pear cactus that occurs naturally in just two widely-separated locations in the Florida Keys. Flowers emerge orange and fade to red with age. Fruits are very rare and, when present, are thought to be produced by asexual means. Most reproduction in Semaphore cactus happens vegetatively, when young “pups” fall from a parent plant and disperse to a new site. The threats to the survival of Semaphore cactus are many and include sea level rise, climate change, development, herbivory by larvae of the accidentally introduced moth Cactoblastis cactorum, impacts from mammals including Key Deer (another federally endangered species), secondary fungal pathogens which infect stressed plants, and lack of sexual reproduction. The moth Cactoblastis cactorum is native to South America and was exported to Australia as a biological means of controlling invasive pricklypears way back in 1925. It was so successful that the Aussies actually erected a monument as a gesture of gratitude toward the bug. Unfortunately for us, a few of the tiny caterpillars can completely decimate even a large Semaphore cactus.

Where is Florida Semaphore Cactus (Consolea corallicola) located in the wild?

Habitat:

Found in a rocky, well-drained hardwood hammock.

Distribution:

There exists only one population of eight genetically distinct individuals and several hundred small clones (from fallen pads), located in the Florida Keys. Historically, this cactus was known from Key Largo and Big Pine Key, but development has destroyed these populations. The only \"wild\" population remaining is in a Nature Preserve.

States & Provinces:

Florida Semaphore Cactus can be found in Florida

Which CPC Partners conserve Florida Semaphore Cactus (Consolea corallicola)?

Fairchild Tropical Botanic Garden

Not Sponsored

Conservation Actions

Assigned 06/09/17

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

Center for Plant Conservation

11/26/2021

At Site 50 under the direction of the Florida Department of Environmental Protection in 1996, 110 pads of Consolea corallicola (syn. Opuntia corallicola)from Fairchild Tropical Botanic Garden ex situ collection were outplanted into hammock and in buttonwood ecotone. In 1999, FDEP removed the plants from the hammock sites since that did not seem to be the appropriate habitat. One of the hammock sites had high mortality due to the Cuban garden snail. This site also had a dense canopy of sapodilla which we believe adversely affected the plants. In 2003, an additional 58 pads were outplanted into coastal rock barren. In 2004, an additional 30 pads were outplanted at another coastal rock barren site. Janice Duquesnel continues to monitor for flowering, recruitment and survival, maintaining an accurate GIS map and tagging records. As of Oct 2008, water levels at both coastal rock barren sites were higher than normal, indicative of the extreme high tides in the fall. A total of 66 plants are viable, 16 indivuals died; 10 individuals records with dead basal pads have vegetative pups.

Center for Plant Conservation

11/25/2021

The Florida Semaphore cactus, Opuntia corallicola, is a rare species with a distribution limited to one island in the Florida Keys. The only 12 mature, flowering individuals known to exist in 1989 were threatened by the arrival of an exotic cactus feeding moth, Cactoblastis cactorum. Cages were erected in 1990 around these cacti to protect them from Cactoblastis. From 1990 to 1998 the O. corallicola population was monitored and number of new recruits were measured. In May 1996, The Nature Conservancy made an out-planting of 96 small, new cacti derived from fallen pads, in an experimental regime designed to bolster the number of extant cacti and to test for the effectiveness of cages as a protection against Cactoblastis. Both the natural and the outplanted population declined by over 30% during out monitoring periods. In both the natural population and the experimental outplanting most individuals died because of what appeared to be stem browning, probably by a plant pathogen. The next largest cause of mortality in the outplanting was trampling by Key deer. Cactoblastis destroyed one mature cactus but killed no individuals in the outplanting. A hurricane in 1998 was a minor cause of death for outplanted individuals but killed two mature cacti.

10/05/2020

10/05/2020

Fairchild Tropical Garden has sufficient numbers of propagules to conduct reintroductions. Because their collection contains propagules of now-dead parent plants, it contains more genetic diversity than the current wild population

Jennifer Possley

01/01/2010

Threats include habitat destruction, collection by cactus enthusiasts, exotic cactus moth larvae, calt water intrusion, canopy closure, lack of genetic diversity, and pathogens. The cactus moth, is greatly threatening the health of the remaining individuals. The population has survived as well as it has through careful management by The Nature Conservancy, and through the help of volunteers who check the cacti for cactus moth larvae each week.

Jennifer Possley

01/01/2010

Eight individuals in one "wild" population remain. Several dozen individuals are found at ouplanted sites and an unknown number on private lands.

Jennifer Possley

01/01/2010

Negron-Ortiz determined O. corallicola to be reproductively sterile, showing that it is self-incompatible and does not reproduce sexually. Seedling recruitment does not occur in nature; rather, new propagules are formed clonally by fallen pads and (sterile) flower buds. Dr. Peter Stiling of University of South Florida in Tampa has conducted life history research, and is currently investigating the cause of a brown rot that plagues many of the cacti. Fairchild Tropical Garden is in the beginning stages of a long-term greenhouse study, investigating the effects of salinity and light levels on cactus health.

Jennifer Possley

01/01/2010

The Florida Keys chapter of The Nature Conservancy has set up a regular, consistent monitoring program. On an biannual basis, cacti are measured, and flowers and rooted propagules are counted. In addition, TNC coordinates the efforts of volunteers who monitor the cacti for cactus moth larvae every week, removing any larvae they find. The Florida Dept. of Environmental Protection manages and monitors the outplanting on Key Largo.

Jennifer Possley

01/01/2010

Additional suitable reintroducing sites with available staff for monitoring need to be located.

Jennifer Possley

01/01/2010