Torreya taxifolia
| Torreya taxifolia | |
|---|---|
 |
|
| Leaves of Torreya taxifolia | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Cephalotaxaceae |
| Genus: | Torreya |
| Species: | T. taxifolia |
| Binomial name | |
| Torreya taxifolia Arn. |
|
Torreya taxifolia, commonly known as the Florida torreya, gopher wood, stinking yew, or stinking cedar (although not closely related to the true yews or cedars), is a rare and endangered species found in the Southeastern United States, at the state border region of northern Florida and southwestern Georgia.
It is the type species of the genus Torreya. Torreya taxifolia became one of the first federally listed endangered plant species in the United States in 1984; the IUCN lists the species as critically endangered. A survey conducted in 2000 estimated the population of T. taxifolia to be between 500 and 4000 individuals.
Contents |
[edit] Description
Torreya taxifolia is an evergreen tree that may reach heights of 15 to 20 meters. The trees are conical in overall shape, with whorled branches and stiff, sharp pointed, needle-like leaves 2-3.5 cm long and 3 mm broad. The male (pollen) cones are 5-7 mm long, grouped in lines along the underside of a shoot. The female (seed) cones are single or grouped two to five together on a short stem; minute at first, they mature in about 18 months to a drupe-like structure with the single large nut-like seed 2-3.5 cm long surrounded by a fleshy covering, dark green to purple at full maturity in the fall. The leaves and cones have a strongly pungent resinous odor when crushed, leading to its popular names "stinking yew" and "stinking cedar".
[edit] Habitat
Today, Torreya taxifolia is restricted to bluffs and ravines within Torreya State Park, along the east bank of the Apalachicola River in the Florida Panhandle and immediately adjacent southernmost Georgia. Most stands are composed of immature trees of less than 2 meters tall. The population of mature trees crashed in the 1950s, possibly due to the introduction of a still uncharacterised fungal disease. Up to 11 species of fungi attack T. taxifolia, including species of Physalospora and Macrophoma. Fungicide treatment has been shown to be effective for fungal infection, with plants showing renewed growth after treatment. Recovery of the species may be inhibited by postglacial global warming, as it is best adapted to the cooler, moister climate found in this area during the last ice age. It may not have been able to move north in the postglacial warming, due to poor dispersal abilities.
[edit] Assisted Migration to the southern Appalachians
Torreya Guardians is a volunteer group of citizen-naturalists, botanists, ecologists, and landowners that has formed with the mission of finding and implementing ways outside the jurisdiction of the Endangered Species Act to use private seed stock to establish groves of Torreya taxifolia trees in the southern Appalachians and points north, such that viable seeds will then be available for rewilding this tree onto private lands far enough north and at high enough elevations to resist the diseases already brought about by global warming in its endemic habitat in Florida. The idea is that Torreya taxifolia for some reason was unable to migrate on its own back north from its "ice age pocket refuge" in northern Florida, and that assisted migration will thus help this species return to its traditional interglacial range in the Appalachian Mountains. The January 2007 issue of Conservation Magazine depicted Torreya taxifolia as the lead candidate for assisted migration owing to global warming. The May/June 2008 issue of "Orion Magazine" includes an in-depth review of the controversy, pro and con, of assisted migration for T. taxifolia.
[edit] Cultivation and uses
In the 19th century, the tree was harvested for wood that was used as fenceposts, shingles, furniture and as a fuel for riverboats on the Apalachicola River.
[edit] Landscape
Cultivated specimens are, however, growing very well in cooler climates in the Appalachian Mountains, in northern Georgia and at the Biltmore Gardens in Asheville, North Carolina, where it is regenerating naturally. The proposed best course to save the species from extinction is to plant groves of it in these areas.
[edit] References and external links
- Conifer Specialist Group (2000). Torreya taxifolia. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Listed as Critically Endangered (CR A1c v2.3)
- Schwartz, M.W. et al. 2000. Estimating the magnitude of decline of the Florida torreya (Torreya taxifolia Arn.). Biological Conservation 95:77-84
- U.S. Fish and Wildlife Service. 1984. Federal Register (pdf)
- U.S. Forestry Service. Torreya taxifolia
- Fox, Douglas. 2007. When worlds collide. Conservation 8(1):28-34.
- Nijhuis, Michelle. 2008. Taking Wildness in Hand: Rescuing Species. Orion Magazine May/June 2008, pp. 64–78.
- Proposals for re-establishment.
- Flora of North America: Torreya taxifolia RangeMap:
