Torreya

Torreya
Torreya nucifera
Scientific classification
Kingdom:	Plantae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Cephalotaxaceae
Genus:	Torreya Arn.
Species
Torreya californica Torreya fargesii Torreya grandis Torreya jackii Torreya nucifera Torreya taxifolia
Synonyms
Tumion Raf. ex Greene[1]

Torreya is a genus of conifers comprising five or six species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. Four are native to eastern Asia; the other two are native to North America. They are small to medium-sized evergreen trees reaching 5-20 m, rarely 25 m, tall. Common names include nutmeg yew.^[2]

The leaves are spirally arranged on the shoots, but twisted at the base to lie in two flat ranks; they are linear, 2-8 cm long and 3-4 mm broad, hard in texture, with a sharp spine tip.

Torreya can be either monoecious or dioecious; when monoecious, the male and female cones are often on different branches. The male (pollen) cones are 5-8 mm long, grouped in lines along the underside of a shoot. The female (seed) cones are single or grouped two to eight 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 2-4 cm long surrounded by a fleshy covering, green to purple at full maturity. In some species, notably the Japanese Torreya nucifera ('Kaya'), the seed is edible. Natural dispersal is thought to be aided by squirrels which bury the seeds for a winter food source; any seeds left uneaten are then able to germinate.

The genus is named after the American botanist John Torrey.

Torreya californica (California torreya) is endemic in California. It is the largest species, reaching 25 m tall.

Torreya taxifolia (Florida torreya or gopher wood) has a restricted habitat within Torreya State Park, along the east bank of the Apalachicola River in the Florida Panhandle and immediately adjacent southernmost Georgia. Elvy E. Callaway claimed it was the "gopher wood" used to build Noah's Ark. It is an endangered species, which has suffered a major decline in numbers due to fungal disease (possibly Phytophthora), and postglacial global warming; however, cultivated specimens are growing very well and regenerating naturally in cooler climates of northern Georgia and western North Carolina. Called "assisted migration", intentional movement of a plant outside of its historical range (though perhaps consistent with its deep-time range) became an important issue in the conservation community in 2007 and 2008, with T. taxifolia being the featured plant.^{[3][4] [5][6]}

References

1. ^ W. H. Camp, H. W. Rickett and C. A. Weatherby 1947. International rules of botanical nomenclature, Appendix III: Nomina Generica Conservanda. Brittonia, 6(1):1–120 (Section 10, page 47) [1]
2. ^ Eckenwalder, J.E. 2009. Conifers of the World: The Complete Reference. Timber Press.
3. ^ Fox, Douglas. (2007). Conservation 8 (1): 28–34. http://www.conbio.org/cip/article81whe.cfm When worlds collide. 
4. ^ Nijhuis, Michelle (2008). "Taking Wildness in Hand: Rescuing Species". Orion Magazine 2008 (May/June): 64–78. http://www.orionmagazine.org/index.php/articles/article/2966/. 
5. ^ Shirey, P.D. and G.A. Lamberti (2010). "Assisted colonization under the U.S. Endangered Species Act". Conservation Letters 3( (1): 45–52. http://www3.interscience.wiley.com/cgi-bin/fulltext/123196255/PDFSTART. 
6. ^ "Assisted Migration (Assisted Colonization, Managed Relocation) and Rewilding of Plants and Animals in an Era of Global Warming". Torreya Guardians. http://www.torreyaguardians.org/assisted-migration.html. 

• Gymnosperm Database
• Proposals for Torreya taxifolia re-establishment
• Torreya State Park (Florida, USA)
• Photos: Torreya californica, Torreya nucifera
• Native Conifers of North America: Torreya