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Wildlife, Animals, and Plants
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Introductory
SPECIES: Taxus floridana | Florida Yew
ABBREVIATION :
TAXFLO
SYNONYMS :
NO-ENTRY
SCS PLANT CODE :
TAFL
COMMON NAMES :
Florida yew
TAXONOMY :
The currently accepted scientific name for Florida yew is Taxus
floridana Nutt. ex Chapm. [6,12]. There are no accepted infrataxa.
LIFE FORM :
Tree, Shrub
FEDERAL LEGAL STATUS :
Notice of Review, Category 2
OTHER STATUS :
The state of Florida lists Florida yew as endangered [28]. The Natural
Heritage Program lists Florida yew as imperiled because of rarity or
because of vulnerability to extinction (global and state rank 2) [2].
Florida yew is listed by The Nature Conservancy as imperiled because of
rarity and limited range [7].
COMPILED BY AND DATE :
Janet Sullivan, December 1993
LAST REVISED BY AND DATE :
NO-ENTRY
AUTHORSHIP AND CITATION :
Sullivan, Janet. 1993. Taxus floridana. In: Remainder of Citation
DISTRIBUTION AND OCCURRENCE
SPECIES: Taxus floridana | Florida Yew
GENERAL DISTRIBUTION :
Florida yew is known only from bluffs and ravines along the Apalachicola
River in northwestern Florida, in Gadsden and Liberty counties [6,7].
Several populations occur along a 15-mile [24 km] stretch of the river
[7,11,12]. A single population was reported by Kurz [10] in an Atlantic
white-cedar (Chamaecyparis thyoides) swamp 8 miles [12.8 km] southeast
of Bristol, Florida. The Nature Conservancy, however, reported that no
further observations of the Atlantic white-cedar swamp population have
been made [7].
ECOSYSTEMS :
FRES12 Longleaf - slash pine
FRES16 Oak - gum - cypress
STATES :
FL
ADMINISTRATIVE UNITS :
NO-ENTRY
BLM PHYSIOGRAPHIC REGIONS :
NO-ENTRY
KUCHLER PLANT ASSOCIATIONS :
K112 Southern mixed forest
SAF COVER TYPES :
70 Longleaf pine
74 Cabbage palmetto
97 Atlantic white-cedar
SRM (RANGELAND) COVER TYPES :
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES :
Florida yew usually occurs in small clonal stands or clumps and rarely
as individual stems [7,20]. It occurs as disjunct populations of
several hundred to several thousand stems per hectare in hardwood
forests dominated by American beech (Fagus grandiflora) and southern
magnolia (Magnolia grandiflora), in both open forest habitats and dense
mountain-laurel (Kalmia latifolia) thickets. It is an important
component of the forest understory in some drainages [20]. Florida yew
occurs in habitats which include the rare Florida torreya (Torreya
taxifolia), false hellebore (Veratrum woodii), and bladdernut (Staphylea
trifolia). More common species occurring with Florida yew include
laurel oak (Quercus laurifolia), American beech, horse sugar (Symplocos
tinctoria), highbush blueberry (Vaccinium corymbosum), and in an
Atlantic white-cedar swamp, inkberry (Ilex glabra) [10,20]. Additional
species that occur with Florida yew as reported by Southeastern Forestry
Services [20] include white oak (Q. alba), mockernut hickory (Carya
tomentosa), tree sparkleberry (V. arboreum), and yaupon (I. vomitoria).
On lower slopes the forests are dominated by American beech, southern
magnolia, and American holly (I. opaca). In some ravines Florida yew
occurs in dense stands of fetterbush (Leucothoe racemosa),
mountain-laurel, greenbriers (Smilax spp.), and canebreak (Arundinaria
spp.). No indicator species associated with Florida yew have yet been
identified. Southeastern Forestry Services suggested that differences
in soil, aspect, moisture, or a combination of these factors may
influence the distribution of Florida yew, and that further research is
needed.
VALUE AND USE
SPECIES: Taxus floridana | Florida Yew
WOOD PRODUCTS VALUE :
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Birds consume almost of all ripe Florida yew cones [6]. The relatively
small distribution of this tree makes it unlikely that it is an
important food source for any species. White-tailed deer rubs on
Florida yew are common, sometimes causing extensive damage or death to
the stem. Florida yew is a preferred food for beavers. Yellow-bellied
sapsuckers excavate Florida yew for insects; holes characteristic of
this bird were found on mature Florida yew stems [20].
PALATABILITY :
NO-ENTRY
NUTRITIONAL VALUE :
NO-ENTRY
COVER VALUE :
NO-ENTRY
VALUE FOR REHABILITATION OF DISTURBED SITES :
NO-ENTRY
OTHER USES AND VALUES :
Taxol, a compound used to combat cancer, has been isolated from Florida
yew bark [7].
MANAGEMENT CONSIDERATIONS :
Florida yew occurs in forests that may be subject to logging and/or
other private development. It has also been found to contain taxol in
quantities similar to those found in Pacific yew (Taxus brevifolia), and
may be exploited for that purpose. This may pose a major threat to
Florida yew, considering the small number of extant individuals and its
extremely restricted range. If in vitro production of taxol is
developed, exploitation of Florida yew for taxol production may become
less of a threat to remaining populations [7].
Florida yew occurs in some areas that have been protected (The Nature
Conservancy's Apalachicola Bluffs and Ravines Preserve and Torreya State
Park), but many populations remain without specific protection.
Long-term monitoring programs, artificial propagation studies, and
studies on the fungi associated with Florida yew (as possible taxol
producers) are underway. Further studies on its reproductive biology
and other ecological characteristics have been recommended [7].
The seeds and fresh foliage are poisonous to humans [3].
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Taxus floridana | Florida Yew
GENERAL BOTANICAL CHARACTERISTICS :
Florida yew is a native, evergreen, small, bushy tree or shrub [3,6,12].
Maximum height at maturity is usually 26 feet (8 m), although one survey
reported an individual that was 30 feet (9 m) tall and 6.5 inches (16.5
cm) d.b.h. [3,6,20]. The bark is purplish brown, sloughing in plates.
The leaves are needlelike, flat, linear, and somewhat falcate, 0.8 to 1
inch (2-2.5 cm) long. The branches are arranged in an irregular manner,
long branches are often oriented ar nearly right angles to the trunk.
Even though the wood is hard when dried, live trunks are flexible [16].
The ovulate cones occur singly in only a few leaf axils [6]. The
ovulate cones have a fleshy outer covering (aril) that is 0.4 inch (10
mm) broad [3].
RAUNKIAER LIFE FORM :
Phanerophyte
REGENERATION PROCESSES :
Florida yew is dioecious [16]. The seeds of other yews (Taxus spp.)
often take two growing seasons to germinate. Passage through the
digestive tract of birds is probably required for germination of any yew
seed [17]. Seedling recruitment in Florida yew varies among sites. The
majority of seedlings occur under female Florida yew trees, but seedling
height growth is negatively affected by the presence and density of a
canopy. Of one hundred tagged seedlings at each of two sites, 21 and 39
percent survived to 10 months. Seedlings are apparently only moderately
shade tolerant; very low levels of seedling recruitment were observed at
the site which had a closed canopy [16].
Florida yews form clonal stands largely through layering [16], although
root sprouts have also been reported [20]. Stems which have had their
tops chewed off by beavers will sprout, resulting in a bushy growth form
[20]. Individual Florida yew stems often fall over after reaching
maturity, or have branches forced to the ground by overstory branches or
stems which allows new Florida yew stems to form. The flexible trunk
and long branches of Florida yew appear to facilitate the formation of
clonal stands. Female genets have significantly more ramets than male
genets [16].
SITE CHARACTERISTICS :
Florida yew occurs on steep slopes in the ravines and occasionally on
bluffs along the the Apalachicola River. Soils are slightly acidic to
neutral sandy loams [7,10]. Florida yew occurs at elevations between
upland sandhill (longleaf pine [Pinus palustris]) habitats and very
moist ravine bottoms [1,13]. It also occurs in an acidic peat (pH
range 4.2-4.5) swamp [10].
SUCCESSIONAL STATUS :
Facultative Seral Species
Florida yew is tolerant of shade. Seed germination occurs under light
to deep shade, although seedling establishment and survival are low
under very deep shade [16]. Florida yew is, however, apparently adapted
to disturbance. Disturbances that topple Florida yew stems, such as
shifting sands or windfall of overstory stems create opportunites for
new ramet formation, often downslope of the original stem. Individual
stems of Florida yew may be relatively short-lived, but genets may be
long-lived, shifting location along slopes. The largest (and oldest)
genets are often found on the lowest slopes [27].
SEASONAL DEVELOPMENT :
Florida yew arils mature in September or early October of their first
season [3].
FIRE ECOLOGY
SPECIES: Taxus floridana | Florida Yew
FIRE ECOLOGY OR ADAPTATIONS :
Florida yew occurs in humid forests on moderate to steep slopes that
rarely burn. Fire was historically frequent in the longleaf pine/grass
habitats upland of these slopes; observers note that surface fires there
often burn to the edges of the slopes and then naturally extinguish
[24]. Fires in the mesic hammocks in which Florida yew occurs usually
originate elsewhere, and consist of surface fires that creep and burn
only litter [27]. Florida yew will sprout after tops have been damaged
by means other than fire. It is possible that fire-damaged stems may
respond the same way. Sprouts that form after tops have been damaged,
however, are of low vigor and do not usually survive [25]. Other yews
are very susceptible to heat damage and rarely sprout after fire [26].
POSTFIRE REGENERATION STRATEGY :
Tree with adventitious-bud root crown/soboliferous species root sucker
FIRE EFFECTS
SPECIES: Taxus floridana | Florida Yew
IMMEDIATE FIRE EFFECT ON PLANT :
Florida yew is probably easily killed by fire.
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
NO-ENTRY
PLANT RESPONSE TO FIRE :
NO-ENTRY
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
NO-ENTRY
FIRE MANAGEMENT CONSIDERATIONS :
Fires in Florida yew habitats would probably be detrimental to Florida
yew populations [19].
REFERENCES
SPECIES: Taxus floridana | Florida Yew
REFERENCES :
1. Boyles-Sprenkel, Carolee. 1993. Restoring a "grass-roots" forest.
American Forests. 99(5&6): 43-45, 60-61. [21284]
2. Chafin, L. 1993 [pers. com.]
3. Duncan, Wilbur H.; Duncan, Marion B. 1988. Trees of the southeastern
United States. Athens, GA: The University of Georgia Press. 322 p.
[12764]
4. Eyre, F. H., ed. 1980. Forest cover types of the United States and
Canada. Washington, DC: Society of American Foresters. 148 p. [905]
5. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others].
1977. Vegetation and environmental features of forest and range
ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of
Agriculture, Forest Service. 68 p. [998]
6. Godfrey, Robert K. 1988. Trees, shrubs, and woody vines of northern
Florida and adjacent Georgia and Alabama. Athens, GA: The University of
Georgia Press. 734 p. [10239]
7. Guala, Stinger. 1993. Element stewardship abstract for Taxus floridana,
Florida yew. Arlington, Virginia: The Nature Conservancy. 8 p. On file
at: U.S. Department of Agriculture, Forest Service, Intermountain
Research Station, Fire Sciences. [22193]
8. Gueritte-Voegelein, Francoise; Guenard, Daniel; Potier, Pierre. 1987.
Taxol and derivatives: a biogenetic hypothesis. Journal of Natural
Products. 50(1): 9-18. [12625]
9. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation
of the conterminous United States. Special Publication No. 36. New York:
American Geographical Society. 77 p. [1384]
10. Kurz, Herman. 1927. A new and remarkable habitat for the endemic Florida
yew. Torreya. 27: 90-92. [22192]
11. Little, Elbert L., Jr. 1975. Rare and local conifers in the United
States. Conservation Research Rep. No. 19. Washington, DC: U.S.
Department of Agriculture, Forest Service. 25 p. [15691]
12. Little, Elbert L., Jr. 1979. Checklist of United States trees (native
and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of
Agriculture, Forest Service. 375 p. [2952]
13. Nicholson, Rob. 1990. Chasing ghosts. Natural History. 12: 8,10-13.
[21788]
14. Preston, Richard J., Jr. 1948. North American trees. Ames, IA: The Iowa
State College Press. 371 p. [1913]
15. Raunkiaer, C. 1934. The life forms of plants and statistical plant
geography. Oxford: Clarendon Press. 632 p. [2843]
16. Redmond, Ann M. 1984. Population ecology of Taxus floridana (Nutt.), a
dioecious, understory tree. Tallahassee, FL: The Florida State
University. 47 p. Thesis. [22427]
17. Rudolf, Paul O. 1974. Taxus L. yew. In: Schopmeyer, C. S., ed. Seeds of
woody plants in the United States. Agric. Handb. 450. Washington, DC:
U.S. Department of Agriculture, Forest Service: 799-802. [7763]
18. Scher, Stanley; Schwarzschild, Bert. 1989. Pacific yew: a facultative
riparian conifer with an uncertain future. In: Proceedings of the
California riparian systems conference: protection, management, and
restoration for the 1990's; 1988 September 22-24; Davis, CA. Gen. Tech.
Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest
Service, Pacific Southwest Forest and Range Experiment Station: 172-175.
[13426]
19. Self, David; Kelly, Eugene M. 1988. Rare plant monitoring and prescribed
burning initiated at the Apalachicola Bluffs and Ravines Preserve
(Florida). Restoration & Management Notes. 6(2): 91. [10144]
20. Southeastern Wildlife Services, Inc. 1982. A distribution survey of the
populations of Taxus floridana and Torreya taxifolia in Florida.
Contract No.: 14-16-0004-81-069. Atlanta, GA: U.S. Department of the
Interior, Fish and Wildlife Service. 11 p. On file with: U.S. Department
of Agriculture, Forest Service, Intermountain Research Station, Fire
Sciences Lab, Missoula, MT. [22194]
21. Stalter, Richard. 1990. Torreya taxifolia Arn. Florida torreya. In:
Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics
of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC:
U.S. Department of Agriculture, Forest Service: 601-603. [13420]
22. Stickney, Peter F. 1989. Seral origin of species originating in northern
Rocky Mountain forests. Unpublished draft on file at: U.S. Department of
Agriculture, Forest Service, Intermountain Research Station, Fire
Sciences Laboratory, Missoula, MT; RWU 4403 files. 7 p. [20090]
23. U.S. Department of Agriculture, Soil Conservation Service. 1994. Plants
of the U.S.--alphabetical listing. Washington, DC: U.S. Department of
Agriculture, Soil Conservation Service. 954 p. [23104]
24. Martin, D. L. 1993 [pers. com.]
25. Redmond, A. 1993 [pers. com.]
26. Bolsinger, Charles L.; Jaramillo, Annabelle E. 1990. Taxus brevifolia
Nutt. Pacific yew. In: Burns, Russell M.; Honkala, Barbara H.,
technical coordinators. Silvics of North America. Volume 1. Conifers.
Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture,
Forest Service: 573-579. [13417]
27. Platt, William J.; Schwartz, Mark W. 1990. Temperate hardwood forests.
In: Myers, Ronald L.; Ewel, John J., eds. Ecosystems of Florida.
Orlando, FL: University of Central Florida Press: 194-229. [17390]
28. Wood, Don A., compiler. 1994. Official lists of endangered & potentially
endangered fauna and flora in Florida. Tallahassee, FL: Florida Game and
Fresh Water Fish Commission. 22 p. [24196]
29. U.S. Department of the Interior, Fish and Wildlife Service. 1993. 50 CFR
Part 17: Plant taxa for listing as endangered or threatened species;
notice of review--September 30, 1993. Federal Register. 58(188):
51144-51190. [23816]
Index
Related categories for Species: Taxus floridana
| Florida Yew
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