Encephalartos woodii
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.JPG/250px-Encephalartos_woodii_(Londra).JPG) Encephalartos woodii in the Royal Botanic Gardens, Kew
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| Encephalartos woodii Sander |
Encephalartos woodii, also known as Wood's Cycad, is a cycad in the genus Encephalartos, endemic to the Natal area of South Africa. It is one of the rarest plants in the world, being extinct in the wild with all specimens being clones of the type.
It is treelike, and can reach a height of 6 m tall (≈20 feet). The trunk is about 30-50 cm diameter, thickest at the bottom, and topped by a crown of 50-150 leaves. The leaves are glossy and dark green, 150-250 cm (≈6-8 feet) in length, and keeled with 70-150 leaflets, the leaflets falcate (sickle-shaped), 13-15 cm long and 20-30 mm broad.[2][3]
E. woodii is dioecious, meaning it has separate male and female plants. The male strobili are cylindrical, 20-40 cm long, exceptionally up to 120 cm (≈47 inches), and 15-25 cm diameter; they are a vivid yellow-orange colour. A single plant may bear from around six to eight simultaneously. The female cones are unknown, as no female plant has ever been discovered. Encephalartos woodii also reproduces with rapidly-growing suckers.[2][3]
It was found only in a forested area and biodiversity hotbed in the Natal region of South Africa.[4]
[edit] Taxonomy
Encephalartos woodii is most closely related to E. natalensis. Some authorities consider E. woodii to not be a true species but rather a mutant E. natalensis or a relic of some other species. Yet others consider this plant to be a natural hybrid between E. natalensis and E. ferox.[2]
The specific and common name both honour John Medley Wood, curator of the Durban Botanic Garden and director of the Natal Government Herbarium of South Africa, who discovered the specimen in 1907.[5] It was first described by Wood as a variety of E. altensteinii (as E. altensteinii var. bispinna), and raised to the rank of species in 1908 by the English horticulturalist Henry Sander.[3]
[edit] Conservation status
The only known wild plants of E. woodii were a cluster of four stems of one plant discovered by Wood in 1895 in a small area of Ngoya Forest, in what is now South Africa. The smaller shoots were cut in 1903. Four years later, another expedition collected the two smaller stems and placed them into botanical gardens. Of the two remaining stems, the larger one died sometime during the period 1907-12. The last stem was removed from the wild in 1916 and sent to Pretoria, where it subsequently died in 1964.[2] All known specimens of Encephalartos woodii are clones of that only known plant. Despite several surveys, no other plant has ever been located in the wild. For those reasons, the plant is considered extinct in the wild.[1] As is the case with all members of the genus Encephalartos, E. woodii, including both mature plants and seeds, is listed in Appendix I of CITES.[2]
As a consequence of all known plants being male, it may be said that "Encephalartos woodii hasn't had sex in about a hundred years".[4] Unless a female plant is found, E. woodii will never reproduce naturally. However, the next best thing has been accomplished. Wood's Cycad forms fertile hybrids with E. natalensis. If each offspring is subsequently crossed with E. woodii and the process is then repeated, after several generations, the female offspring will be close to what a female Encephalartos woodii would be like.[2]
[edit] References
- ^ a b Donaldson, J.S. (2003). 'Encephalartos woodii'. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 2006-11-16.
- ^ a b c d e f Notten, A. (May 2002). Encephalartos woodii Sander. Kirstenbosch National Botanical Garden and South African National Biodiversity Institute. Retrieved on 2006-11-16.
- ^ a b c Hill, K. (2004). Encephalartos woodii. Royal Botanic Gardens Sydney. Retrieved on 2006-12-01.
- ^ a b Morell, V. (February 1998). The Sixth Extinction. National Geographic Magazine online. National Geographic Society. Retrieved on 2006-11-16.
- ^ Encephalartos woodii. Cycads. Kew Botanical Gardens. Retrieved on 2006-11-16.
