Encephalartos Woodii

''Encephalartos woodii'', Wood's cycad, is a rare cycad in the genus ''Encephalartos'', and is endemic to the oNgoye Forest of KwaZulu-Natal, 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. 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 plant in 1895.

Description

It is palm tree like, and can reach a height of . The trunk is about in diameter, thickest at the bottom, and topped by a crown of 50–150 leaves. The leaves are glossy and dark green, in length, and keeled with 70–150 leaflets, the leaflets falcate (sickle-shaped), long and broad.

''E. woodii'' is dioecious, meaning it has separate male and female plants; however, no female plant has ever been discovered. The male strobili are cylindrical, long, exceptionally up to , and in diameter; they are a vivid yellow-orange colour. A single plant may bear from around six to eight simultaneously.

Taxonomy

''Encephalartos woodii'' 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 from studying a specimen in his collection, which was apparently one of the basal offsets taken from the original clump. It has been considered that ''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 relict of some other species. Yet others consider this plant to be a natural hybrid between ''E. natalensis'' and '' E. ferox''. To determine the relationship between ''E. natalensis'' and ''E. woodii'', the RAPD technique was used to generate genetic fingerprints and data analysed using distance methods. Based on RAPD fingerprints, the intraspecific genetic variation among different ''E. natalensis'' plants is similar to the interspecific variation between ''E. natalensis'' and ''E. woodii'', which confirms the close relationship between ''E. natalensis'' and ''E. woodii''.

Distribution and habitat

Original distribution

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, now known by its proper Zulu name of ''oNgoye'', which is in KwaZulu-Natal, South Africa. The site where this plant was found was on a steep south-facing slope on the fringes of the forest. The annual rainfall at the site ranges between , and the climate has hot summers and mild winters.

Removal from natural habitat

A basal offset of the main stems was removed and sent to Kew Gardens in 1899. Three basal offsets were collected by Wood's deputy, James Wylie, in 1903 and planted in the Durban Botanic Gardens. One specimen was received at the National Botanic Gardens of Ireland in Glasnevin in 1905Czech Cycads: Cycads in Ireland: http://www.cykasy.cz/English/Cycads_in_Ireland.html, retrieved 20 September 2010. where the register records it as "''Encephalartos way of E. Alten teinii'" costing 1 guinea from Sander & Sons.National Botanical Gardens, Glasnevin: Conservation News: http://www.botanicgardens.ie/conserve/consnews.htm , retrieved 20 September 2010. In a 1907 expedition, Wylie collected two of the larger stems and noted that of the remaining two, one of them (the largest of the four original stems) was badly mutilated and he did not expect it to survive. By 1912 there was only one tall trunk left in the wild, and in 1916, the Forestry Department arranged to have it removed and sent to the Government Botanist in Pretoria. It is thought that this trunk subsequently died in 1964.

Current distribution

While extinct in the wild, ''Encephalartos woodii'' specimens are found in many botanical gardens, institutions and collections around the world, with an estimated 500 individuals in existence, all clones of the original specimen. For an ''Encephalartos'' cycad, ''E. woodii'' is relatively fast-growing and vigorous in cultivation.

Two of the larger trunks that Wylie collected in the 1907 expedition are still to be seen in the Durban Botanic Gardens. A sucker from one of the Durban Botanic Gardens plants was sent to Kirstenbosch near Cape Town, South Africa in 1916 by James Wylie. The plant that was sent to Kew Gardens in 1899 was grown in the Palm House until April 1997 and then moved to the Temperate House where it produced, for the first time, a male cone in September 2004. Other European specimens include one housed at Hortus Botanicus in Amsterdam, the Netherlands, and one in Orto Botanico di Napoli in Italy, although this specimen may have died. The specimen in Ireland at Glasnevin is said to be "probably the tallest" specimen of ''E. woodii'' in Europe. In the United States, a specimen is housed in the conservatory at Longwood Gardens near Philadelphia, Pennsylvania and three specimens are to be seen at Lotusland in Santa Barbara, California where they were planted in 1979. The specimen at Longwood Gardens was received in 1969 after a request was made to the Durban Botanic Gardens by one of Longwood's former directors, Dr. Russell Seibert, when he went on a plant exploration voyage to South Africa in the 1960s. The rooted plant was first taken to the Research Department at Longwood where the gardeners nurtured the plant until it was ready to be displayed in the Conservatory. The Longwood specimen produces cones in early winter.

Conservation status

Despite numerous excursions in the oNgoye-Mtunzini area, no other specimens of ''Encephalartos woodii'' have ever been found. All known specimens of ''Encephalartos woodii'' are clones of the only known male plant which was completely removed from the wild. For these reasons, the plant is considered extinct in the wild.

Legislation

As is the case with all members of the genus ''Encephalartos'', ''Encephalartos woodii'' is protected by both national and international legislation:

In South Africa one requires a permit from Nature Conservation to move, sell, buy, donate, receive, cultivate and sell Endangered Flora and to own adult cycads.
On an international level all species and hybrids of ''Encephalartos'' are on Appendix I of CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora. This means that wild collected material may not be traded and for each and every artificially cultivated ''Encephalartos'' plant or piece of a plant or a cone or pollen or seed, being carried over an international border requires a CITES Export Permit issued by the authority of the exporting country, and a CITES Import Permit issued by the authority of the importing country.

Reproduction and propagation

Vegetative reproduction

''Encephalartos woodii'' reproduces with rapidly growing suckers.

Sexual reproduction

Unless a female plant is found, ''E. woodii'' will never reproduce naturally. This species is known to form fertile hybrids with ''E. natalensis'', and a backcrossing technique can be used: if each offspring is subsequently crossed with ''E. woodii'' and the process is then repeated, after several generations, female offspring will be closer to what a female ''Encephalartos woodii'' would be like. However, genetic analysis of chloroplast DNA of F1 hybrids between ''E. woodii'' and ''E. natalensis'' showed that all chloroplasts are inherited from the female ''E. natalensis'', indicating that multi-generational hybrid offspring would have ''E. natalensis'' chloroplasts and could never be "pure" ''E. woodii''.

Distribution of hybrids

Several hybrids between ''E. woodii'' and other species of ''Encephalartos'' have been produced including:
* ''Encephalartos gratus'' x ''E. woodii'' at Lotus Land, California.
* ''Encephalartos natalensis'' x ''E. woodii'' at Orto botanico di Palermo in Italy, and in various collections in South Africa and the United States.
* ''Encephalartos transvenosus'' x ''E. woodii'' in collections in South Africa and the United States.
* ''Encephalartos arenarius x E. woodii'' at Aloes in Wonderland, California.
* '' Encephalartos horridus x E. woodii'' at Aloes in Wonderland, California.

Gallery

File:Encephalartos woodii - bark- Kirstenbosch botanical garden - 2.jpg, The bark of the specimen planted in Kirstenbosch botanical garden
File:Encephalartos woodii young stem cone lower leaflets 12 09 2010.JPG, Male cone of ''Encephalartos woodii''
File:Encephalartos woodii male cone _california.JPG, Male cone of ''Encephalartos woodii'' compared to a human
File:Encephalartos woodii medium shade leaf 12 09 2010.JPG, Portion of a leaf showing leaflets
File:Ongoye colonial.jpg, The last two stems of ''Encephalartos woodii'' at oNgoye in the early 1900s
File:Encephalartos woodii true original stem side 12 09 2010.JPG, One of the original stems at the Durban Botanic Gardens
File:Durban Botanical Gardens original E woodii stem.jpg, Original stem at Durban Botanic Gardens, 2010
File:Encephalartos woodii true original stem branch 12 09 2010.JPG, Offshoots (suckers) showing roots developing on the largest one
File:Encephalartos natalensis x woodii Female.jpg, A female ''E. natalensis'' x ''woodii'' with cones
File:Encephalartos woodii x natalensis01.jpg, ''Encephalartos natalensis'' x ''E. woodii'' hybrid at Orto botanico di Palermo

References

External links

Detailed information on ''E. woodii'' at Kirstenbosch

{{Taxonbar, from=Q1989057

woodii
Endemic flora of South Africa
Trees of South Africa
Extinct biota of Africa
Plants extinct in the wild
Flora of KwaZulu-Natal
Critically endangered flora of Africa
Endlings
Taxa named by Henry Frederick Conrad Sander
Plants described in 1908