| Franklinia | |
|---|---|
| Flower and leaves in the fall | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Ericales |
| Family: | Theaceae |
| Genus: | Franklinia W.Bartram ex Marshall, 1785 |
| Species: | F. alatamaha |
| Binomial name | |
| Franklinia alatamaha W.Bartram ex Marshall |
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Franklinia is a monotypic genus in the tea plant 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. (Tsou 1998). Hybrid crosses have been produced between Franklinia alatamaha and Gordonia lasianthus, and between Franklinia alatamaha and Schima argentea. (Orton 1977; Ranney et al. 2003).
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Franklinia alatamaha is a deciduous large shrub or small tree growing to 10 m (33 ft) tall, but commonly 4.5–7.5 m (15–25 ft). It is commercially available for garden cultivation. It is prized for its fragrant white flowers, similar to camellia blossoms.it has flowers that smell like honeysuckles. The tree has a symmetrical, somewhat pyramidal shape, with different individuals of the species forming almost identical crowns. It forms 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 Franklinia can live a century or more.
Franklinia fruit develops slowly. The seed capsules require 12–14 months to mature. When ripe the 5-valved spherical capsules split above and below in a unique manner. Anecdotal evidence suggests viable seed production is enhanced where two or more plants are present in close proximity.
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 Franklinia 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 of Franklinia back to Philadelphia in 1777, and had flowering plants by 1781. After several years of study, 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).
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. See: Bozeman and Rogers 1986). 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. (Dirr 1998: 390-391).
All the Franklin trees known to exist today are descended from seed collected by William Bartram and propagated at Bartram's Garden in Philadelphia.[2]
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 a root-rot disease and does not endure drought well.[3]