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Franklinia

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Franklinia
Flower and leaves in autumn
Scientific classificationEdit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Ericales
Family: Theaceae
Genus: Franklinia
W.BartramexMarshall[3]
Species:
F. alatamaha
Binomial name
Franklinia alatamaha
W.Bartram ex Marshall[3]
Natural range
Synonyms[3]
  • Franklinia alatamaRaf.
  • Gordonia frankliniiL'Hér.
  • Gordonia pubescensL'Hér.

Frankliniais amonotypicgenus in theteafamily,Theaceae.The sole species in this genus is a flowering tree,Franklinia alatamaha,commonly called theFranklin tree,and native to theAltamaha Rivervalley inGeorgiain the southeasternUnited States.It has beenextinct in the wildsince the early 19th century, but survives as a cultivated ornamental tree.

In the past, somebotanistshave includedFrankliniawithin the related genusGordonia.The southeastern North American speciesGordonia lasianthusdiffers in havingevergreenfoliage, flowers with longer stems, winged seeds, and conicalseed capsules.Frankliniawas often known asGordonia pubescensuntil the middle of the 20th century.

Frankliniais now thought to be closer in relation to the Asian genusSchima.Recent DNA studies and examinations of floralontogenyin the Theaceae placeFrankliniatogether withGordoniaandSchimain asubtribe.[4]Hybrid crosseshave been produced betweenFranklinia alatamahaandGordonia lasianthus,and betweenFranklinia alatamahaandSchima argentea.[5][6]

Description

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Franklinia alatamahais a smalldeciduoustreegrowing to 10 m (33 ft) tall, but commonly 4.5–7.5 m (15–25 ft).[7]It is prized for its fragrant white flowers, similar to single whiteCamelliablossoms; the smell may remind some of orange blossoms orhoneysuckle.[8]The tree has a symmetrical, somewhat pyramidal shape, often with different individuals of the species forming almost identical crowns. It frequently suckers and can form several vertical trunks close to ground level. The bark is gray with vertical white striations and has a ridged texture. The alternate, obovate leaves are up to 6 in (15 cm) in length and turn a bright orange-red in the fall. Although difficult totransplant,once established,F. alatamahacan live a century or more.

Theseed capsulesrequire 12–14 months to mature. Unlike almost all angiosperms,Franklinia alatamahaexhibits zygotic dormancy. It pollinates in late summer or early autumn, is then dormant over winter, and only sets fruit during the subsequent summer. Female gametophytes are mature prior to pollination, with double fertilization occurring soon after pollination. Thezygotebecomes dormant immediately after fertilization with delay of development until the following summer. Initial development of endosperm occurs for up to 3 months after fertilization but comes to a standstill at winter's onset. With onset of the following summer, embryogenesis begins and endosperm development restarts. This overwinter zygotic dormancy is extremely rare among temperate angiosperms.[9]When ripe the pentavalved spherical capsulessplitabove and below in a unique manner.

History

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"No tree which ornaments our gardens has a more romantic history," begins a lengthy 1933 article published inThe Pennsylvania Magazine of History and Biography.The history ofFranklinia's discovery in coastal Georgia, followed by disappearance in the wild, and saved only by its ability to grow, flower, and seed in the Philadelphia garden of its initial collector entail the main thread of the unusual botanical history.[10]

Franklinia alatamahaby William Bartram (1782)

PhiladelphiabotanistsJohnandWilliam Bartramfirst observed the tree growing along theAltamaha Rivernear Fort Barrington in the British colony ofGeorgiain October 1765. John Bartram recorded "severall very curious shrubs" in his journal entry for October 1, 1765. William Bartram returned several times to the same location on the Altamaha during a collecting trip to the American South, funded by Dr. John Fothergill of London. William Bartram collectedF. alatamahaseedsduring this extended trip to the South from 1773 through 1776, a journey described in his bookBartram's Travelspublished in Philadelphia in 1791. William Bartram brought seed back to Philadelphia in 1777 at which time William reported to his father that he had relocated the plant, but this time had been able to retrieve its seeds although it was not until after John's death (1777) that he was able to achieve flowering plants (1781). After several years of study, William Bartram assigned the "rare and elegant flowering shrub" to a new genusFranklinia,named in honor of his father's great friendBenjamin Franklin.The new plant name,Franklinia alatamaha,was first published by a Bartram cousin,Humphry Marshall,in 1785 in his catalogue of North American trees and shrubs entitledArbustrum Americanum.(Marshall 1785: 48–50; Fry 2001).

William Bartram was the first to report the extremely limited distribution ofFranklinia."We never saw it grow in any other place, nor have I ever since seen it growing wild, in all my travels, from Pennsylvania toPoint Coupe,on the banks of the Mississippi, which must be allowed a very singular and unaccountable circumstance; at this place there are two or 3 acres (12,000 m2) of ground where it grows plentifully. "(W. Bartram 1791: 468). After returning to Georgia after the American Revolution, Bartram was unable to find the trees.[11]

The tree was last verified in the wild in 1803 by the English plant collector John Lyon (although there are hints it may have been present into at least the 1840s).[12]The cause of its extinction in the wild is not known, but has been attributed to a number of causes including fire, flood, overcollection by plant collectors, andfungaldiseaseintroduced with the cultivation ofcottonplants.[13]

All the Franklin trees known to exist today are descended from seed collected by William Bartram and propagated atBartram's Gardenin Philadelphia. It has now been cultivated in over 1000 sites worldwide including botanical gardens, private homes, parks, and cemeteries.[14][15]It is suggested that more than one tree was sampled by Bartram during his original collection in Georgia and the diversity was maintained over the years.[16]To mark the 300th anniversary of John Bartram's birth in 1998, Bartram's Garden launched a project to locate as manyFrankliniatrees as possible.[15]

Status as a glacial relict

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There have been efforts to reintroduce the species to its native habitat. Twenty-four individuals were planted between 2002 and 2003 in the Altamaha Wildlife Management Area; however, they were unsuccessful.[17]The idea of reintroduction was long controversial for some plant enthusiasts who believed wild populations may still exist.[18]The lack of success in returning an extinct-in-the-wild plant to its formerly native range is not unexpected for those aware of Franklinia's status as aglacial relict.

In eastern North America, lowlandglacial refugesalong the Atlantic and Gulf Coasts hostendemicplants — some of which are rare, even endangered, and others entail the most southerlydisjunct populationsof plants that commonly appear only hundreds of miles to the north. Major rivers draining southward from theAppalachian Mountainsare associated with a gradation ofpaleoendemictree species. These range from the extinctCritchfield sprucenear the outlet of theMississippi River,to extinct-in-the-wildFrankliniaalong theAltamaha River,to the critically endangeredFlorida torreyaandFlorida yewat the downstream end of theChattahoochee Riversystem.[19][20](See illustration at right.)

As with Florida torreya, the relictual status of the now-extinct wild population of Franklinia near the mouth of a major river draining theAppalachian Mountainssouthward makes investigation of proximal causes of disease secondary to the likelihood of the plant having lost viability as theHolocenewarmed.[21]While seeds may passively float long distances downstream, this mode of dispersal became unavailable for making the reverse trip back to the mountains to track a warming climate.[22]As with Florida torreya, evidence that climate warming accounts as ultimate cause is reinforced by today's disease-free health of horticultural plantings far to the north (Cleveland, Ohio, for Florida torreya).[23]Northward growing successes contrast with professional failures that have attempted to restore either species to reproductive health in their refugial riverside patches where each apparently survived peak episodes of glacial cold during thePleistoceneepoch.[21]

Cultivation

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The Franklin tree has a reputation among gardeners for being difficult to cultivate, especially in urban environments. It prefers sandy, high-acid soil, and does not tolerate compacted clay soil, excessive moisture, or any disturbance to its roots. The Franklin tree has no known pests, but it is subject to root-rot and crown-rot caused byPhytophthora cinnamomi[24]and does not endure drought well.[25]It is commercially available for garden cultivation.[26]

It is one of two species of trees in the tea family that only exists in cultivation, the other beingCamellia amplexicaulis.[27]

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  • Leaves
    Leaves
  • Leaf closeup
    Leaf closeup
  • Trunk bark
    Trunk bark
  • Fall leaves
    Fall leaves
  • Flower
    Flower
  • Fruit capsule
    Fruit capsule

References

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Wikimedia Commons has media related toFranklinia alatamaha.
Wikispecieshas information related toFranklinia alatamaha.
  1. ^Rivers, M.C. (2015)."Franklinia alatamaha".IUCN Red List of Threatened Species.2015:e.T30408A62077322.doi:10.2305/IUCN.UK.2015-2.RLTS.T30408A62077322.en.Retrieved19 November2021.
  2. ^"Franklinia alatamaha.NatureServe Explorer 2.0 ".explorer.natureserve.org.Retrieved20 March2023.
  3. ^abcFranklinia alatamahawas originally described and published inArbustrum Americanum: The American Grove, or, an Alphabetical Catalogue of Forest Trees and Shrubs, Natives of the American United States, Arranged according to the Linnaean System.Philadelphia. 49 (-50). 1785."Franklinia alatamaha".Germplasm Resources Information Network.Agricultural Research Service,United States Department of Agriculture.RetrievedNovember 20,2012.
  4. ^Tsou, Chih-Hua. 1998. "Early Floral Development of Camellioideae (Theaceae)," American Journal of Botany, 85(11), p. 1531-1547.
  5. ^Orton, Elwin R., Jr. 1977. "Successful Hybridization of Gordonia lasianthus (L.) Ellis x Franklinia alatamaha Marshall," American Association of Botanical Gardens and Arboreta, vol. 11, no. 4 (October), p. 81-84.
  6. ^Ranney, Thomas G. and Thomas A. Eaker, Paul R. Frantz, Clifford R. Parks. 2003 "xSchimlinia floridbunda (Theaceae): A New Intergeneric Hybrid between Franklinia alatamaha and Schima argentea," HortScience, vol. 38(6), October, p. 1198-1200.
  7. ^Gladfelter, H.J., Yadav, L.K., Merkle, S.A. et al. Genetic diversity and population structure analysis of Franklinia alatamaha, a tree species existing only in cultivation. Tree Genetics & Genomes 16, 60 (2020).https://doi.org/10.1007/s11295-020-01455-x
  8. ^"Botanist's Lens: Fragrant Jewels in the Gardens at London Town".6 August 2019.
  9. ^Kristel M. Schoonderwoerd, William E. Friedman, Zygotic dormancy underlies prolonged seed development in Franklinia alatamaha (Theaceae): a most unusual case of reproductive phenology in angiosperms, Botanical Journal of the Linnean Society, Volume 181, Issue 1, May 2016, Pages 70–83,https://doi.org/10.1111/boj.12409
  10. ^Jenkins, Charles F (1933)."The Historical Background of Franklin's Tree".The Pennsylvania Magazine of History and Biography.58(3): 193–208.JSTOR20086836.Retrieved11 December2022.
  11. ^Owens, Simon J.; Rix, Martyn (August 2007)."595. FRANKLINIA ALATAMAHA.: Theaceae".Curtis's Botanical Magazine.24(3): 186–189.doi:10.1111/j.1467-8748.2007.00586.x.ISSN1355-4905.
  12. ^Bozeman, John R. and George A. Rogers. 1986. “‘This very curious tree’: Despite years of searching and research the enigma ofFranklinia alatamahaendures,”Tipularia,(November), p. 9-15.
  13. ^Dirr, Michael A. 1998. Manual of Woody Landscape Plants: Their Identification, Ornamental Characteristics, Culture, Propagation and Uses. Stipes Publishing L.L.C.: Champaign, IL.
  14. ^Bartram's Garden (Philadelphia, Pa., USA), "The Franklinia Story,"http://www.bartramsgarden.org/franklinia/index.htmlArchived2007-08-21 at theWayback Machine,accessed 1 July 2007.
  15. ^abMeier, Allison C. (2018-04-27)."America's Mysterious Lost Tree".JSTOR Daily.Retrieved2020-08-07.
  16. ^Gladfelter, Heather J.; Yadav, Lav K.; Merkle, Scott A.; Wilde, H. Dayton (2020-07-30)."Genetic diversity and population structure analysis of Franklinia alatamaha, a tree species existing only in cultivation".Tree Genetics & Genomes.16(4).doi:10.1007/s11295-020-01455-x.ISSN1614-2942.S2CID220881412.
  17. ^Williams, Kevan (16 September 2014)."Have Tree, Will Travel"(PDF).Landscape Architecture Magazine.JSTOR44796081.Retrieved11 December2022.
  18. ^Dickson, Terry (23 April 2002)."Tree's replanting upsets botanists".The Florida Times-Union.Archived fromthe originalon 22 August 2016.
  19. ^Delcourt, Hazel R; Delcourt, Paul A (October 1975). "The Blufflands: Pleistocene Pathways into the Tunica Hills".American Midland Naturalist.94(2): 385–400.doi:10.2307/2424434.JSTOR2424434.
  20. ^Barlow, Connie."Paleoecology and the Assisted Migration Debate: Why a Deep-Time Perspective Is Vital (Torreya taxifoliaas exemplar) ".Torreya Guardians.Retrieved23 June2022.
  21. ^abWilliams, Kevan (September 2014)."Have Tree, Will Travel"(PDF).Landscape Architecture Magazine.104(9): 50–58.
  22. ^"Florida Torreya (Torreya taxifolia) Recovery Plan, 1986 "(PDF).ECOS Environmental Conservation Online Systems.U.S. Fish and Wildlife Service.Retrieved12 July2022.
  23. ^Barlow, Connie."Historic Groves of Torreya Trees: Long-term Experiments in Assisted Migration".Torreya Guardians.Retrieved19 July2022.
  24. ^Koslow G, Peterson JL (1980) Phytophthora root and crown rot of Franklinia trees. J Arboricult 6:89–92
  25. ^U.S. Forest Service, "Franklinia Alatamaha, Franklin-Tree," Fact Sheet ST-260, November 1993.
  26. ^"Franklinia | Longwood Gardens".[permanent dead link]
  27. ^Barstow, Megan (4 January 2018)."Two of the world's tea species extinct in the wild according to new report".Global Trees.Retrieved18 October2021.
  • Owens, Simon J., and Martyn Rix. "595. FRANKLINIA ALATAMAHA: Theaceae." Curtis's Botanical Magazine (1995), vol. 24, no. 3, BLACKWELL PUBLISHING, 2007, pp. 186–89,doi:10.1111/j.1467-8748.2007.00586.x.
  • Bartram, William. 1791.Travels Through North & South Carolina, Georgia, East & West Florida,….James & Johnson: Philadelphia.
  • Fry, Joel T. 2000. "Franklinia alatamaha, A History of that '‘Very Curious' Shrub, Part 1: Discovery and Naming of the Franklinia",Bartram Broadside,(Spring), p. 1-24.
  • Marshall, Humphry. 1785.Arbustrum Americanum. The American Grove, or an Alphabetical Catalogue of Forest Trees and Shrubs, Natives of the American United States, Arranged According to the Linnaean System…,Joseph Cruikshank: Philadelphia.
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