(DRAFT) - Taxonomy
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
TAXONOMY
NAME - CACTUS, TREE-, KEY
OTHER COMMON NAMES - CACTUS, TREE-, KEY; CACTUS, TREE; CACTUS, TREE, JIJIRA; CEPHALOCEREUS, DEERING; CEPHALOCEREUS and KEY WEST
ELEMENT CODE -
CATEGORY - Angiosperm
PHYLUM AND SUBPHYLUM - MAGNOLIOPHYTA,
CLASS AND SUBCLASS - MAGNOLIOPSIDA,
ORDER AND SUBORDER - CARYOPHYLLALES,
FAMILY AND SUBFAMILY - CACTACEAE,
GENUS AND SUBGENUS - CEREUS,
SPECIES AND SSP - ROBINII,
SCIENTIFIC NAME - CEREUS ROBINII
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Key Tree-cactus
Cereus robinii (Lemaire) L. Benson
KINGDOM: Plant GROUP: Angiosperm
DIVISION: Magnoliophyta CLASS: Magnoliopsida
ORDER: Caryophyllales FAMILY: Cactaceae
Cereus robinii is a large, tree-like cactus with erect columnar
stems, reaching 10 m in height. Plants much-branched (var. robinii),
or remaining few-branched (var. deeringii), at maturity. Stems
cylindrical, green, succulent; 5-10 cm thick, with 9-15 prominent
ribs. Areoles bearing 15-30 acicular spines, to 2 cm long. Areoles
thickly pubescent when young, the hair caducous. Flowers solitary in
the upper areoles, nocturnal, 5-6 cm long. Outer perianth segments
green, with tips pointed (var. robinii) or rounded (var. deeringii).
Inner perianth segments white. Style slightly exserted (var. robinii)
or included (var. deeringii). Fruit globose, depressed, 3.504 cm in
diameter. Fruit coat thin, leathery, bright red and splitting open at
maturity. Seed small, hard, shiny black; set in a soft, white pulp
(06,08,17).
Cereus robinii was first described (as Pilocereus robinii) by
Lemaire (08) who considered it endemic to the northwestern coast of
Taxonomy - 1 (DRAFT) - Taxonomy
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
Cuba. The species was transferred to the genus Cephalocereus by
Britton and Rose (07). In 1957, Leon and Alain retained the genus
Pilocereus for this species and treated it as endemic to Cuba (11).
The genus Pilocereus was rejected on nomenclatural grounds by Byles
and Rowley who proposed Pilosocereus as a replacement and transferred
Pilocereus robinii to that genus (12). This change was taken up by
Lioger (12). More recently, Benson, citing the uncertainties of
generic boundaries within the ceroid cacti, transferred the species
into an inclusive Cereus (21). Most modern authors prefer to place C.
robinii and related species in the genus Cephalocereus (01,05,07,08,
20,23).
The Florida plants now referred to as Cereus robinii were
originally described as two separate species (in Cephalocereus).
Cephalocereus keyensis Britton and Rose was described from plants
collected in Key West (07). Cephalocereus deeringii Small was
described from plants found growing on Lower Matecumbe Key (14).
Common names are the Key West Cephalocereus and the Deering
Cephalocereus respectively.
They were placed in synonomy under the Cuban species Cereus
robinii by Benson who identified Cephalocereus keyensis with Cereus
robinii and treated Cephalocereus deeringii as a distinct subspecies,
Cereus robinii var. deeringii (21). This treatment was confused by
Long and Lakela who equated Cephalocereus keyensis with Cereus robinii
var. deeringii and Cephalocereus deeringii with Cereus robinii var.
robinii (13). Benson has since published his own book covering the
species, in which he maintains his original treatment (06). D.F.
Austin has recently published some observations on the species in
which he questions the distinctiveness of the two varieties (03). The
critical studies of character variation within natural populations
required to clarify such taxonomic problems have not been carried out.
The type specimen for Cephalocereus deeringii Small is located in
the New York Botanical Garden: Small 7790, 8 April 1916, Lower
Matecumbe Key, Monroe Co., Florida. Illustrations may be found in 06,
14, 17, 24, and 25.
Illustrations for Cephalocereus keyensis Britton and Rose can be
found in 06 and 24.
Other common names for this species include tree cactus and the
IUCN Red Data Book uses Jijira tree cactus.
Taxonomy - 2 (DRAFT) - Status
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
STATUS
Coded Status
Florida; Federal Endangered
Florida; Officially Listed
Florida; Unofficially Listed
E: Federal Endangered
Non-consumptive recreational
Ornamental
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Key tree-cactus (Cereus robinii) has been designated an
Endangered species pursuant to the Endangered Species Act of 1973
(50 CFR 17.12; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540), as
amended. The species has this status wherever found including the
State of Florida and also in Cuba.
Removal and reduction to possession of any Federally listed plant
from an area under Federal jurisdiction is unlawful (50 CFR 17.61 and
17.71).
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Florida
DESIGNATED STATUS: Endangered.
ADMINISTRATIVE AGENCY: Department of Agriculture and Consumer
Affairs.
STATE STATUTES: Preservation of Native Flora of Florida Act,
Section 581.185-187, Florida Statutes.
UNOFFICIAL LIST: Endangered; In: Ward, D.B. 1979. Rare and
endangered biota of Florida, Vol. 5: Plants.
Univ. Presses of Florida. 175 pp.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The Key tree-cactus is listed in Appendix II of CITES and is
listed in the IUCN Plant Red Data Book.
Status - 1 (DRAFT) - Status
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
The U.S. named this species on a provisional list for the Annex
to the Convention on Nature Protection and Wildlife Preservation in
the Western Hemisphere during a conference held in Mar del Plata,
Argentina, in October 1965. This provisional list, including flora
candidates, was subsequently published in a Pan American Union
document with final lists of other member countries in 1967.
The listing in the Annex is by the scientific name Cephalocereus
deeringii (believed extinct and a synonym of Cereus robinii
deeringii), and Cephalocereus keyensis (a synonym of Cereus robinii
robinii).
ECONOMIC STATUSES:
The Key tree-cactus may have commercial value as a horticultural
item. Removal of these plants from the wild for horticultural
purposes does not seem to have had an important effect on the numbers
or distribution of the species. It has never been sold commercially,
and few collectors have ever been interested in growing it. There
are, in fact, no records of populations being destroyed or even
drastically reduced as a result of collecting. In the future,
however, collecting may become more of a threat. The Endangered
status of the species alone will make it more desireable to
collectors. This will lead to collecting pressure on already
diminished populations.
This cactus also has aesthetic, scientific and recreational
(observation) value by virtue of its prominence as the largest cactus
in Florida and as a member of a rare and declining tropical hammock
community.
75/07/01:40 FR 27823/27924 - Smithsonian report
76/06/16:41 FR 24523/ - Proposed rule, Endangered
77/02/22:42 FR 10462/10488 - Implementation of CITES
79/12/10:44 FR 79796/ - Withdrawal of proposal
83/07/29:48 FR 34483/ - Reproposal as Endangered
84/07/19:49 FR 29234/29237 - Final rule, listed as Endangered
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Evergreen Forest Land
COMMENTS ON HABITAT ASSOCIATIONS -
The Key tree-cactus grows in a narrow range of plant associations
which include tropical hardwood hammocks and a thorn-scrub association
known locally as a "cactus hammock".
Hardwood hammocks inhabited by the species are typically in an
early stage of succession following disturbance (04,14,15). Dominant
tree species include Bumelia salicifolia, Bursera simarouba, Cocoloba
diversifolia, Ficus aurea, Krugiodendron ferreum, Metopium toxiferum,
and Piscidia piscipula. The lower story of the canopy typically
contains small trees of the dominant species and plants of Amyris
elemifera, Ateramnus lucidus, Bumelia celastrina, Capparis flexuosa,
Eugenia foetida, Guapira discolor, Pithecellobium guadelupense, Randia
aculeata, and Zanthoxylum fagara (02,19). These hardwood hammocks are
upland communities which are flooded only rarely (during major storms)
and are mesic in character (19).
The thorn-scrub, "cactus hammock", association is lower in
elevation and subject to more frequent flooding. In consequence, the
canopy is both lower and more open than in the hardwood hammock.
Conocarpus erectus and Ximenia americana are the most typical dominant
tree species (19). Cereus gracilis, Cereus pentagonus, and Opuntia
dillenii are common associates of Cereus robinii in these habitats.
Cereus robinii is found on high, rarely flooded sites within the
cactus hammock. These sites support the hardwood hammock species
listed above, but they are rarely extensive enough to allow typical
hardwood hammock development (22).
The hardwood hammocks and cactus hammocks in which C. robinii is
presently known to grow are all developed on coral rock. Mineral soil
consists of a very thin layer of marl or rock rubble. A thin layer
(about 2 cm thick) of leaf litter and humus overlies the mineral
substrate (02).
Hammocks on Key West and Boca Chica Key, where C. robinii grew in
the past, were developed on oolitic limestone. Soil conditions at
these sites were not recorded, but were probably similar to those
listed above.
The major requirements for successful growth of C. robinii are an
open canopy and freedom from frequent floods or frequent fires.
Habitat Associations - 1 (DRAFT) - Food Habits
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
AUTOTROPH
Food Habits - 1 (DRAFT) - Environment Associations
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Coastal Features: Vegetated offshore islands
G
G
Environment Associations - 1 (DRAFT) - Life History
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
LIFE HISTORY
HABIT:
The Key tree-cactus is a succulent (06,08).
LIFE CYCLE:
Analysis of available data suggests C. robinii, as a perennial
plant, typically establishes itself in transient openings within
hammocks, grows as long as sufficient light penetrates the hardwood
canopy, and eventually dies out from the site as the canopy thickness
increases (22).
TYPE OF REPRODUCTION:
Long distance dispersal and the establishment of new populations
is dependent upon the production of seed. But, reproduction within a
single population (a clump) is mostly, if not entirely, vegetative
(22).
REPRODUCTIVE PHENOLOGY:
Germination and budding dates are unknown. Anthesis occurs from
March through September. Fruiting occurs throughout the year, though
there is a peak in flowering during the months of August and September
(04). Seed dispersal, based on one observation, occurs in August (02,
04).
SEX OR SPORE STATUS:
Monoecious (06,08).
POLLINATION, SPORE AND SEED DISSEMINATION:
It is not known how pollen is disseminated, however, internal
dispersal by birds (Cardinalis cardinalis for one) is indicated for
this species (02). The effective dispersers would be those
fruit-eating birds which favor openings in the woods (22).
SEED BIOLOGY:
Nothing is known about the seed biology of this species.
POPULATION BIOLOGY:
Cereus robinii is found growing in small, isolated patches or
clumps in the Florida Keys. The patches may consist of a single
plant, or a group of plants may cover an area of tens of square meters
(02,14). When many plants are found in a clump, most, if not all, of
the separate stems likely represent vegetative offshoots of one or a
few founders (22). Vegetative reproduction is commonly observed as a
result of old stems being knocked to the ground.
No studies have been made which would allow estimation of
survival/mortality rates or recovery rates. There is also no
quantitative information available on population density.
The limits of habitat suitable for the species seem to be defined
by its intolerance of flooding and its inability to compete with
hardwoods for light (22).
Population trends are not known quantitatively for the species,
but suitable habitat, rare in the past, is being destroyed rapidly by
Life History - 1 (DRAFT) - Life History
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
development on the upland areas of the Keys. The decrease in
available habitat has surely led to a significant decline in overall
population (08,15,16).
ECOLOGICAL/EDAPHIC FACTORS:
The Key tree-cactus grows well on well-drained upland sites with
little or no soil development. Mineral soil is represented, if at
all, by a very thin (<1 cm) layer of rock rubble, calcareous sand, or
calcareous marl (02,22). A layer of leaf litter 1-2 cm thick is
typically present (02,22). Deeper accumulations of soil may be found
in pockets and crevices in the rock.
These soils are classified as Histosols (18). They are placed in
the "catch-all" Rockland groups (10). No detailed work has been done
on soil types in the Florida Keys due to their small area,
agricultural insignificance, and lack of well-developed soils.
The species is strongly associated with areas of open or thin
canopy (22).
TROPHIC STATUS:
Phototrophic (06,08).
CHARACTERISTIC DOMINANCE:
The Key tree-cactus is a component of its vegetative community
(02,04,14,22). Stems are more numerous in areas where a hole is
present in the canopy of surrounding hardwoods. Under more dense
canopy coverage, a plant has few, not very vigorous stems.
COMMUNITY ECOLOGY:
The hardwood hammock associated with C. robinii is an assemblage
of broad-leaved evergreen trees from the West Indies (19). It is the
climatic climax forest type on upland areas of the Florida Keys. It
is subject to disturbance (canopy openings) through fire and
hurricane. The openings in which C. robinii grows are slowly closed
in by hammock regrowth (22).
SPECIES INTERRELATIONSHIPS:
None known.
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Suppressing wildfire
Beneficial Controlling/Restricting Off-Road Vehicles
Beneficial Restricting/regulating human disturbance of populations
Beneficial
Beneficial Controlling water levels
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Restricting/regulating human use of habitats
Beneficial Land Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Herbicide Use
Beneficial Controlling/Restricting Agricultural Practice
Beneficial Controlling/Removing Nonnative Vegetation
Beneficial Maintaining Sperm/Seed Banks
Beneficial Stocking captive-reared wild-strain animals
Beneficial Transplanting Wild Eggs/Wild Seeds
Beneficial Rehabilitating Individuals
Beneficial Restricting Poaching
Beneficial Controlling/Restricting Noncommercial Harvest
Beneficial Regulating commercial harvest levels
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Harvesting
Existing Harvesting
COMMENTS ON MANAGEMENT PRACTICES -
Cereus robinii has probably always been rare in Florida. Even in
the days preceeding the development of the Florida Keys for
residential use, populations were uncommon and widely-scattered (14,
15).
The primary cause for this rarity seems to be the rather
restrictive habitat requirements of the species. It grows only on
lightly shaded upland sites, where flooding occurs only during major
storms (22). This habitat is not at all common on the Keys, and,
furthermore, is transient in nature. Upland areas are typically
covered by dense growths of tropical hardwoods, which produce too much
shade for Cereus robinii, or by pinelands which are open but subject
to more-or-less frequent fire. The habitat preferred by Cereus
robinii occurs primarily in disturbed patches of hammock (04,14,15).
The location of these patches changes with time as disturbed areas
regrow and new sites are disturbed.
By far the major threat to the continued existence of this cactus
in Florida is the continued commercial and residential development of
the upland areas in the Keys. This development has been directly
responsible for the destruction of several Cereus populations over the
past seven decades (02,04,08,15,16).
An indirect, and potentially very serious, threat raised by
Management Practices - 1 (DRAFT) - Management Practices
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
Management Practices - 2 (DRAFT) - Management Practices
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
development is the reduction in number of sites available for future
colonization by Cereus robinii. Any single population of the cactus
is vulnerable to destruction through natural disaster or human
activity. This, together with the ultimately transient nature of
suitable habitats, suggests that the Key tree-cactus has been able to
maintain a foothold in Florida only because sites suitable for
colonization have become available, and have been colonized, at a rate
equal to the loss of populations through natural disaster or regrowth
of the hammock canopy (22).
Removal of plants from the wild for horticultural use does not
seem to have ever had an important effect on the numbers or
distribution of the species. It has never been sold commercially, and
few collectors have ever been interested in growing it. There are, in
fact, no records of populations being destroyed or even drastically
reduced as a result of collecting. In the future, however, collecting
may become more of a threat. The endangered status of the species
alone will make it more desirable to collectors. This will lead to
collecting pressure on already diminished populations.
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1986. Key Tree-cactus Recovery Plan.
U.S. Fish and Wildlife Service, Atlanta, GA. 28 pp.
The Recovery Plan for the Key tree cactus (Cereus robinii)
recommends the following actions:
1. Protection of existing sites and individual plants through
appropriate measures including preparation of species management
plan for all 5 sites. These plans would incorporate, as required,
measures to rehabilitate and maintain habitat including control of
non-native vegetation, restrictions on agricultural practices,
land clearing, application of herbicides, use of off-road vehicles,
limiting human access and maintenance of the water table to preclude
saltwater intrusion which may damage the hammock communities. Also
protect the species and habitat by controlling fires, land
acquisition/zoning, controlling pollution, and controlling take
of plants.
2. Determine the community association and reproductive biology of
species.
3. Determine the feasibility and means of introduction and/or
reintroduction. This may involve a seed bank and artificial
propagation for reintroduction into appropriate habitats.
4. Assess the population status in Cuba.
5. Refine recovery goals incorporating information developed in
the recovery process.
At present recovery actions are limited to some site security
measures.
Management Practices - 3 (DRAFT) - Management Practices
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
Management Practices - 4 (DRAFT) - References
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Adams, C.D. 1972. The flowering plants of Jamaica. The
University of the West Indies, Mona Jamaica.
02 Austin, D.F. 1980. Cereus robinii var. robinii and Cereus robinii
var. deeringii. IN: Austin, D.F., C.E. Naumann, and B.E. Tatje,
Endangered and threatened plant species survey in Southern Florida
and the National Key Deer and Great White Heron National Wildlife
Refuges. Report, Endangered Species Office, U.S. Fish and Wildlife
Service, Atlanta, GA. Copy on file at Florida Natural Areas
Inventory office, Tallahassee, FL.
03 Austin, D.F. 1984. A resume of the Florida taxa of Cereus. Fla.
Scientist 47:68-72.
04 Avery, G.N. Undated. Notes on South Florida Plants. Manuscript
in the library of Fairchild Tropical Garden, Miami, FL.
05 Bailey, L.H., E.Z. Baily, et al. 1976. Hortus Third. MacMillan
Publishing Co., Inc. New York, NY.
06 Benson, L. 1982. The Cacti of the United States and Canada.
Stanford Univ. Press, Stanford, CA.
07 Britton, N.L. and J.N. Rose. 1909. The genus Cereus and its
allies in North America. Contr. U.S. National Herb. 12:413-437.
08 Britton, N.L. and J.N. Rose. 1937. The Cactaceae, 2nd edition.
Dover Reprint of 2nd (1937) edition. New York.
09 Hoffmeister, J.E. 1974. Land from the sea. University of Miami
Press. Miami, FL.
10 Jones, L.A. 1948. Soils, geology, and water control in the
Everglades Region. Bulletin No. 442, Univ. Florida Agric. Exp.
Station, Gainesville, FL.
11 Leon, H. and H. Alain. 1957. Flora de Cuba. Part 3. 1974
reprint by Otto Koeltz Science Pub., Koenigstein, FDR.
12 Liogier, A.H. 1969. Flora de Cuba Supplement. 1974 reprint by
Otto Koeltz Science Pub., Koenigstein, FDR.
13 Long, R.W. and O. Lakela. 1971. A flora of tropical Florida.
University of Miami Press, Miami, FL.
14 Small, J.K. 1917. The tree cacti of the Florida Keys. J. New
York Bot. Garden. 18:199-203.
15 Small, J.K. 1921. Old trails and new discoveries. J. New York
Bot. Garden. 22:25-40, 49-64.
16 Small, J.K. 1924. The land where spring meets autumn. J. Ney
York Bot. Garden 25:53-94.
17 Small, J.K. 1931. Cephalocereus deeringii-Deerings tree-cactus,
Addisonia 16:39-40, pl.532.
18 Soil Conservation Service. 1975. Soil taxonomy. Agriculture
Handbook No.436, Soil Conservation Service, U.S. Department of
Agriculture. Washington, D.C.
19 Weiner, A.H. Undated. The hardwood hammocks of the Florida Keys.
National Audubon Society and the Florida Keys Land Trust.
Tavernier, FL.
20 Willis, J.C. 1973. A dictionary of the flowering plants and
ferns. Eighth edition, revised by H.K. Airy Shaw. Cambridge Univ.
Press. Cambridge, England.
References - 1 (DRAFT) - References
Species CACTUS, TREE-, KEY
Species Id ESIS704004
Date 13 MAR 96
21 Benson, L. 1969. The cacti of the United States and Canada - new
names and nomenclatural combinations. I. Cactus and Succulent J.
41:124-127.
22 Herndon, A. 1985. Personal observation.
23 Correll, D.S. and H.B. Correll. 1982. Flora of the Bahama
Archipelago.
24 Britton, N.L. and J.N. Rose. 1920. The Cactaceae, Vol.2. Dover
Publications Inc., New York, NY.
25 Ward, D.B. 1979. Rare and endangered biota of Florida, Vol. 5:
Plants. Fig. 12.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Avery, G.N. 1982. Cereus robinii in Florida. Report in files of
Florida Natural Areas Inventory office, Tallahassee, FL.
02 Benson, L. 1982. The Cacti of the United States and Canada.
Stanford Univ. Press, Stanford, CA.
03 Britton, N.L. and J.N. Rose. 1937. The Cactaceae, 2nd edition.
Dover Reprint of 2nd (1937) edition. New York.
04 Florida Natural Areas Inventory. Site survey reports in files of
Fla. Nat. Areas Inv. office, Tallahassee, FL.
05 Roverts, R.E. 1975. Report on the on-site inspection of the Dove
Sound Tract on Key Largo. Fla. Dept. Nat. Resour. Tallahassee,
FL.
06 Small, J.K. 1917. The tree cacti of the Florida Keys. J. New
York Bot. Garden. 18:199-203.
07 Small, J.K. 1921. Old trails and new discoveries. J. New York
Bot. Garden. 22:25-40, 49-64.
References - 2