Franklinia | |
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Flower and leaves in autumn | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Ericales |
Family: | Theaceae |
Genus: | Franklinia W.Bartram ex Marshall [3] |
Species: | F. alatamaha |
Binomial name | |
Franklinia alatamaha W.Bartram ex Marshall [3] | |
Natural range | |
Synonyms [3] | |
Franklinia is a monotypic genus in the tea family, Theaceae. The sole species in this genus is a flowering tree, Franklinia alatamaha, commonly called the Franklin tree, and native to the Altamaha River valley in Georgia in the southeastern United States. It has been extinct in the wild since the early 19th century, but survives as a cultivated ornamental tree.
In the past, some botanists have included Franklinia within the related genus Gordonia . The southeastern North American species Gordonia lasianthus differs in having evergreen foliage, flowers with longer stems, winged seeds, and conical seed capsules. Franklinia was often known as Gordonia pubescens until the middle of the 20th century.
Franklinia is now thought to be closer in relation to the Asian genus Schima . Recent DNA studies and examinations of floral ontogeny in the Theaceae place Franklinia together with Gordonia and Schima in a subtribe. [4] Hybrid crosses have been produced between Franklinia alatamaha and Gordonia lasianthus, and between Franklinia alatamaha and Schima argentea. [5] [6]
Franklinia alatamaha is a small deciduous tree growing 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 white Camellia blossoms; the smell may remind some of orange blossoms or honeysuckle. [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 to transplant, once established, F. alatamaha can live a century or more.
The seed capsules require 12–14 months to mature. Unlike almost all angiosperms, Franklinia alatamaha exhibits 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. The zygote becomes 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 capsules split above and below in a unique manner.
"No tree which ornaments our gardens has a more romantic history," begins a lengthy 1933 article published in The Pennsylvania Magazine of History and Biography . The history of Franklinia'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]
Philadelphia botanists John and William Bartram first observed the tree growing along the Altamaha River near Fort Barrington in the British colony of Georgia in 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 collected F. alatamaha seeds during this extended trip to the South from 1773 through 1776, a journey described in his book Bartram's Travels published 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 genus Franklinia, named in honor of his father's great friend Benjamin 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 entitled Arbustrum Americanum . (Marshall 1785: 48–50; Fry 2001).
William Bartram was the first to report the extremely limited distribution of Franklinia. "We never saw it grow in any other place, nor have I ever since seen it growing wild, in all my travels, from Pennsylvania to Point 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, and fungal disease introduced with the cultivation of cotton plants. [13]
All the Franklin trees known to exist today are descended from seed collected by William Bartram and propagated at Bartram's Garden in 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 many Franklinia trees as possible. [15]
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 a glacial relict.
In eastern North America, lowland glacial refuges along the Atlantic and Gulf Coasts host endemic plants — some of which are rare, even endangered, and others entail the most southerly disjunct populations of plants that commonly appear only hundreds of miles to the north. Major rivers draining southward from the Appalachian Mountains are associated with a gradation of paleoendemic tree species. These range from the extinct Critchfield spruce near the outlet of the Mississippi River, to extinct-in-the-wild Franklinia along the Altamaha River, to the critically endangered Florida torreya and Florida yew at the downstream end of the Chattahoochee River system. [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 the Appalachian Mountains southward makes investigation of proximal causes of disease secondary to the likelihood of the plant having lost viability as the Holocene warmed. [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 the Pleistocene epoch. [21]
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 by Phytophthora 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 being Camellia amplexicaulis . [27]
Asimina is a genus of small trees or shrubs described as a genus in 1763. Asimina is the only temperate genus in the tropical and subtropical flowering plant family Annonaceae. Asimina have large, simple leaves and large fruit. It is native to eastern North America and collectively referred to as pawpaw. The genus includes the widespread common pawpaw Asimina triloba, which bears the largest edible fruit indigenous to the United States. Pawpaws are native to 26 states of the U.S. and to Ontario in Canada. The common pawpaw is a patch-forming (clonal) understory tree found in well-drained, deep, fertile bottomland and hilly upland habitat. Pawpaws are in the same plant family (Annonaceae) as the custard apple, cherimoya, sweetsop, soursop, and ylang-ylang; the genus is the only member of that family not confined to the tropics. Fossils date to the Cretaceous.
A shrub or bush is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple stems and shorter height, less than 6–10 m (20–33 ft) tall. Small shrubs, less than 2 m (6.6 ft) tall are sometimes termed as subshrubs. Many botanical groups have species that are shrubs, and others that are trees and herbaceous plants instead.
The Altamaha River is a major river in the U.S. state of Georgia. It flows generally eastward for 137 miles (220 km) from its origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Ocean, where it empties into the ocean near Brunswick, Georgia. No dams are directly on the Altamaha, though some are on the Oconee and the Ocmulgee. Including its tributaries, the Altamaha River's drainage basin is about 14,000 square miles (36,000 km2) in size, qualifying it among the larger river basins of the US Atlantic coast.
John Bartram was an American botanist, horticulturist, and explorer, based in Philadelphia, Pennsylvania, for most of his career. Swedish botanist and taxonomist Carl Linnaeus said he was the "greatest natural botanist in the world." Bartram corresponded with and shared North American plants and seeds with a variety of scientists in England and Europe.
William Bartram was an American naturalist, writer and explorer. Bartram was the author of an acclaimed book, now known by the shortened title Bartram's Travels, which chronicled his explorations of the Southern Colonies of British North America from 1773 to 1777. Bartram has been described as "the first naturalist who penetrated the dense tropical forests of Florida".
Theaceae, the tea family, is a family of flowering plants comprising shrubs and trees, including the economically important tea plant, and the ornamental camellias. It can be described as having from seven to 40 genera, depending on the source and the method of circumscription used. The family Ternstroemiaceae has been included within Theaceae; however, the APG III system of 2009 places it instead in Pentaphylacaceae. Most but not all species are native to China and East Asia.
The Bartlett Arboretum and Gardens in Stamford, Connecticut, contains 93 acres of parkland, gardens, landscapes, and hiking trails that focus on the regional plants, ecology and character of Southwestern New England. The Arboretum is open and accessible to the public every day of the year and is located at 151 Brookdale Road.
Gordonia is a genus of flowering plants in the family Theaceae, related to Franklinia, Camellia and Stewartia. Of the roughly 40 species, all but two are native to southeast Asia in southern China, Taiwan and Indochina. The remaining species, G. lasianthus (Loblolly-bay), is native to southeast North America, from Virginia south to Florida and west to Louisiana; G. fruticosa is native to the tropical rainforests of Central and South America, from Costa Rica to Brazil.
Hydrangea quercifolia, commonly known as oakleaf hydrangea or oak-leaved hydrangea, is a species of flowering plant in the family Hydrangeaceae. It is native to the southeastern United States, in woodland habitats from North Carolina west to Tennessee, and south to Florida and Louisiana. A deciduous shrub with white showy flower heads, it is grown as a garden plant, with numerous cultivars available commercially.
Torreya taxifolia, commonly known as Florida torreya or stinking-cedar, but also sometimes as Florida nutmeg or gopher wood, is an endangered subcanopy tree of the yew family, Taxaceae. It is native to only a small glacial refugium in the southeastern United States, at the state border region of northern Florida and southwestern Georgia.
Bartram's Garden is a 50-acre public garden and National Historic Landmark in Southwest Philadelphia, Pennsylvania, situated on the banks of the Tidal Schuylkill River. Founded in 1728 by botanist John Bartram (1699–1777), it is the oldest botanical garden to survive in North America. The Garden is operated by the non-profit John Bartram Association in coordination with Philadelphia Parks and Recreation.
Aesculus parviflora, the bottlebrush buckeye or small-flowered buckeye, is a species of suckering deciduous shrub in the family Sapindaceae. The species is native to the southeastern United States, where it is found primarily in Alabama and Georgia, with a disjunct population in South Carolina along the Savannah River. Its natural habitat is in mesic forests, on bluffs and in ravines.
Bartram's Travels is the short title of naturalist William Bartram's book describing his travels in the American South and encounters with American Indians between 1773 and 1777. The book was published in Philadelphia, Pennsylvania in 1791 by the firm of James & Johnson.
Thomas Meehan, was a noted British-born nurseryman, botanist and author. He worked as a gardener in Kew between 1846 and 1848, moving afterwards to Germantown in Philadelphia. He was the founder of Meehan’s Monthly (1891–1901) and editor of Gardener’s Monthly (1859–1888).
Schima is a genus of evergreen trees belonging to the tea family, Theaceae.
Illicium floridanum is an evergreen shrub native to the Gulf Coast area of the Southern United States, from Florida to Louisiana.
Nyssa biflora, commonly referred to as the swamp tupelo, or swamp black-gum is a species of tupelo that lives in wetland habitats in the United States.
A glacial relict is a population of a species previously common during a glacial period that retreated into refugia during interglacial periods. They are typically cold-adapted species with a distribution restricted to regions and microhabitats that allow them to survive despite climatic changes.
The Torreya Guardians is a self-organized group of conservationists dedicated to facilitating the assisted migration of the Florida torreya by rewilding it further north than its native range in Florida and Georgia. Founded in the early 2000s, the group is often mentioned as an instigator of the assisted migration of forests in North America for conservation and climate adaptation purposes. It is an example of citizen-initiated citizen science.