National Collection of Imperiled Plants

CPC National Collection Plant Profile

Photographer:

Meghan Fellows

Search Alphabetical List Reference Finder CPC Home

CPC National Collection Plant Profile

Zanthoxylum thomasianum

Family:	Rutaceae
Common Name:	St. Thomas prickly-ash
Author:	(Krug & Urban) Krug & Urban ex P. Wilson
Growth Habit:	Tree, Shrub
CPC Number:	4452

Distribution
Protection
Conservation
References

Profile Links

ITIS
Tropicos
PLANTS
Fish & WildLife

enlarge

Photographer: Meghan Fellows
Image Owner: Fairchild Tropical Garden

Zanthoxylum thomasianum is Not Sponsored

Primary custodian for this plant in the CPC National Collection of Endangered Plants is:

Fairchild Tropical Botanic Garden

Zanthoxylum thomasianum

Zanthoxylum thomasianum, an evergreen shrubby-tree, can grow up to 20 feet in height in the semi-evergreen forests of Puerto Rico and the U.S. Virgin Islands. Its trunk reaches up to 4 inches in diameter and is covered by thick spines. The bark, leaves, and fruit are all aromatic. Small male and female flowers grow separately on different plants and produce fruit capsules in September that each contain a shiny black seed about 3/16-inch long.

Distribution & Occurrence

Top

State Range

Puerto Rico
Virgin Islands

Habitat

Zanthoxylum thomasianum grows in rugged hilly areas on soils of volcanic origin, as well as in limestone areas (Vivaldi and Woodbury 1981). Approximately fifty percent of species growing in these semi-evergreen forests are decidous (USFWS 1988). Two strata of trees are usually present. The uppermost continuous stratum is located about 15 to 30 feet high and is mostly composed of deciduous species (USFWS 1988). The lower stratum, at or below 15 feet, is composed of evergreen species (USFWS 1988).

Distribution

Zanthoxylum thomasianum can be found in the semi-evergreen forests of Puerto Rico and the U.S. Virgin Islands (Vivaldi and Woodbury 1981).

Number Left

There are six remaining sites that support less than five hundred individuals; three sites in Puerto Rico and three in the U.S. Virgin Islands (USFWS 1988). The most significant population is in St. Thomas, where the plants cover an area of about 50 acres, and may number close to 250 (USFWS 1988).

Protection

Top

Global Rank:	G1	6/10/1986	Guide to Global Ranks
Federal Status:	LE	10/24/1996	Guide to Federal Status
Recovery Plan:	Yes	4/5/1988

State/Area Protection

State/Area	Rank	Status	Date
Puerto Rico	S1		2/15/1985
Virgin Islands	*FR83		2/14/1984

Conservation, Ecology & Research

Top

Ecological Relationships

Ecological relationships are unknown.

Threats

Modification and destruction of habitat appears to be the most serious threat to the species (Vivaldi and Woodbury 1981). The St. Thomas population occurs on land which has been subdivided into lots and sold for future residential development (USFWS 1988). Plants at other sites are threatened by farming or limestone mining as well as proposed resort development (USFWS 1988). All of the known sites are on private land where existing regulations would provide little or no protection. A population which formerly occurred on a summit at Piedras Chiquitas, Puerto Rico is believed to have been destroyed by hurricane winds (USFWS 1988). A final factor which jeopardizes the species is its rareness and the fact that male and female flowers occur on different plants. The remaining plants in Puerto Rico may be insufficient in number to ensure reproduction.

Current Research Summary

None known.

Current Management Summary

A formalized management plan has not been implemented.

Research Management Needs

Primary management needs include the protection of remaining individuals and habitats. Understanding reproductive biology and ecology will aid in establishing new and maintaining existing populations.

Ex Situ Needs

References

Top

Books (Single Authors)

Little, E.L., Jr.; Woodbury, R.O.; Wadsworth, F.H. 1974. Trees of Puerto Rico and the Virgin Islands: Agriculture Handbook No. 449. Washington, D.C.: U.S. Department of Agriculture, Forest Service.

WWF. 1990. The official World Wildlife Fund (WWF) guide to endangered species of North America. Washington, D.C.: Beacham Publishing. 1180p.

Electronic Sources

(2002). New York Botanical Garden--The Virtual Herbarium. [Searchable Web site] New York Botanical Garden. Fordham Road Bronx, New York. http://scisun.nybg.org:8890/searchdb/owa/wwwspecimen.searchform. Accessed: 2002.

ESIS. (1998). Endangered Species System (ESIS): Fish and Wildlife Exchange. [Web site;] Virginia Tech. http://fwie.fw.vt.edu/WWW/esis/. Accessed: 2002.

FCONSERVE. (2002). Threatened and endangered species in Puerto Rico and the Virgin Islands. Puerto Rico's Conservation Foundation. http://www.tld.net/users/fconserv/List.htm. Accessed: 2002.

USFWS. (1990). Endangered and Threatened Species Accounts. [Web page] U.S. Fish and Wildlife Service, Division of Endangered Species. http://ecos.fws.gov/servlet/TESSSpeciesQuery. Accessed: 2002.

Journal Articles

2002. Threatened Species Flower in British Virgin Islands. UK Overseas Territories, Conservation Forum. Forum News. 1 pp.

Densmore, D. 1986. Endangered Plants of our Caribbean Islands: A Unique Flora Faces Unique Problems. Endangered Species Technical Bulletin. 11, 3: 3-4.

Lippincott, C. 1990. Rare Plant Conservation. Fairchild Tropical Garden Bulletin. 6-15.

Lippincott, C. 1990. Rare Plant Rescue: Exploring the Puerto Rican Archipelago. Fairchild Tropical Garden Bulletin.

USFWS. 1985. Final Rule to Determine Zanthoxylum thomasianum (Prickly-ash) to be an Endangered Species. Federal Register. 50, 245: 51867-51870.

USFWS. 1985. Proposed Endangered Status for Caribbean Plant. Endangered Species Technical Bulletin. 10, 3: 4.

USFWS. 1985. Proposed Endangered Status for Zanthoxylum thomasianum (Prickly-ash). Federal Register. 50, 28: 5647-5650.

USFWS. 1986. Caribbean Plants. Endangered Species Technical Bulletin. 11, 3: 4.

Reports

USFWS. 1988. St. Thomas prickly ash recovery plan. Atlanta, Georgia: U.S. Fish and Wildlife Service.

Vivaldi, J.L.; Woodbury, R.O. 1981. Zanthoxylum thomasianum (Krug and Urban) P. Wilson. Mayaguez, Puerto Rico: Status report submitted to the U.S. Fish and Wildlife Service.

Search Other National Collection Profiles

This profile was updated on 3/4/2010