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| Division: Cycadophyta |
| Class: Cycadopsida |
| Order: Cycadales |
| Family: Zamiaceae |
| Genus: Encephalartos |
| Species: E. woodii |
Conservation Status: |
E. woodii
Wood's CycadEncephalartos woodii, Wood's cycad, is famous for being extinct in nature, and for the fact that there is no known female specimen on Earth. It may well be the loneliest plant in the world.
It is endemic to the oNgoye Forest of KwaZulu-Natal, South Africa. It is one of the rarest plants in the world, 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.
Encephalartos woodii is a very handsome plant. The leaves are a dark glossy green, 2 to 3 m long, with a gracefully arching shape, giving this cycad a dense umbrella-shaped crown, even in young specimens. The Kirstenbosch specimen is unbranched, but mature specimens are often branched at the crown.
Encephalartos woodii reaches majestic proportions, up to 6 m in height with a trunk diameter of up to 900 mm at the base, 600 mm nearer the crown. The 100+ year-old specimens at Durban Botanic Gardens trunk circumference exceeds 2 m and has an estimated mass of 2,5 tons.
A characteristic that is unique to Encephalartos woodii is that in mature specimens the trunk broadens towards the base, forming a kind of buttress in order to support the weight of the trunk. Furthermore, towards the base of the trunk the leaf bases are so compressed by the weight it supports that the trunk is unusually smooth. At Kirstenbosch the base of the trunk is obscured by a cage that surrounds plant, put there in the 1980s to prevent suckers from being stolen again.
Encephalartos woodii produces six to eight bright orange-yellow cones. These are large, cylindrical in shape, 40 - 90 cm long, occasionally reaching a length of 1,2 m, with a diameter of 150 - 200 mm. Cones are formed on the Kirstenbosch specimen every 2-3 years, and the pollen has been used to create hybrids with a number of species in our collection.
E. woodii is very well represented in botanic gardens and cycad collections throughout the world. Possibly as many as 500 specimens exist, all of them derived from basal suckers or offsets from the original plants discovered by John Medley Wood. The Kirstenbosch specimen was acquired in 1916, also a sucker from one of the Durban Botanic Garden plants.
Encephalartos woodii is considered to be most closely related to Encephalartos natalensis. Some authorities regard it as a relic from a species now extinct, others as a mutation within Encephalartos natalensis or a robust form of this species. Still others regard it as a natural hybrid between Encephalartos natalensis and Encephalartos ferox.
Cultivation:
Encephalartos woodii is possibly the most sought-after cycad in the world. It is fortunate that it is the fastest growing species of Encephalartos and one of the most vigorous in cultivation. It produces numerous suckers, and new leaves are formed every year.
For optimum growth, Encephalartos woodii requires fertile well-drained soil and ample water. It can withstand relatively long dry spells, but plants that receive regular water are healthier and have larger leaves. During summer give sufficient water to soak the root area once a week. Watering can be suspended during winter. Remember that good drainage is crucial. In hot dry regions inland, the sun tends to burn the leaves and they are better planted in light shade.
A mulch of well-rotted compost applied at least once a year around the base of the plant, plus application of a balanced fertiliser twice a year during summer (1 kg to each mature plant), will keep the plant in good condition and maintain growth.
Encephalartos woodii makes a good container plant when small, but will have to be planted out when it becomes too large. All our cycads make ideal outdoor container plants, but remember to position them where the sharp leaf spines will not do damage to passing human traffic. Use a well-drained soil mix, e.g. 6 parts coarse sand : 8 parts milled bark : 6 parts friable loam. Add dolomitic lime, iron sulphate and a slow release inorganic fertiliser.
Encephalartos woodii, being fast-growing, will quickly fill the container up with its roots and, if not repotted, may burst the pot with its expanding roots. Cycads in containers require watering every other day during summer, particularly during hot and windy weather, and must never be allowed to dry out completely. It is important that the growing medium be kept moist, but the excess water must be allowed to drain away to prevent rotting.
Propagation is by offsets and suckers. Encephalartos woodii does not go completely dormant, but growth does slow down during winter. Suckers are best removed in early spring, with a clean sharp spade or a knife. They should be larger than 100 mm in diameter; the larger the sucker the better its chance of survival away from its parent. Treat all cut surfaces, on the parent and the sucker, with flowers of sulphur to prevent fungal infection. Store the sucker in a cool dry place for about three weeks to allow the wound to seal. Before planting, dust the wound with a rooting hormone to stimulate the development of roots. Keep moist and in light shade until it produces new leaves, whereafter a weekly feed with a balanced liquid fertiliser during summer is recommended.
There being no female plant, seed is out of the question, but there are a few projects underway to remedy the situation. There is still the hope that a female plant is in the Ngoye forest somewhere and expeditions in that area always keep a look out for one.
The most promising project is the crossing of Encephalartos woodii with its closest relative Encephalartos natalensis, and crossing the offspring with Encephalartos woodii again with the result that each successive generation is more and more Encephalartos woodii.
There is also the remote possibility that a spontaneous sex change will occur in one of the male plants. Sex reversal has been observed in a few cases involving other species and once the process is more fully understood, it could be induced in an Encephalartos woodii plant.
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| semi-shade | dark green | low watering | fast growth | frost-resistant | unobtainable |
Encephalartos woodii is possibly the most sought-after cycad in the world. It is fortunate that it is the fastest growing species of Encephalartos and one of the most vigorous in cultivation. It produces numerous suckers, and new leaves are formed every year.
For optimum growth, Encephalartos woodii requires fertile well-drained soil and ample water. It can withstand relatively long dry spells, but plants that receive regular water are healthier and have larger leaves. During summer give sufficient water to soak the root area once a week. Watering can be suspended during winter. Remember that good drainage is crucial. In hot dry regions inland, the sun tends to burn the leaves and they are better planted in light shade.
A mulch of well-rotted compost applied at least once a year around the base of the plant, plus application of a balanced fertiliser twice a year during summer (1 kg to each mature plant), will keep the plant in good condition and maintain growth.
Encephalartos woodii makes a good container plant when small, but will have to be planted out when it becomes too large. All our cycads make ideal outdoor container plants, but remember to position them where the sharp leaf spines will not do damage to passing human traffic. Use a well-drained soil mix, e.g. 6 parts coarse sand : 8 parts milled bark : 6 parts friable loam. Add dolomitic lime, iron sulphate and a slow release inorganic fertiliser.
Encephalartos woodii, being fast-growing, will quickly fill the container up with its roots and, if not repotted, may burst the pot with its expanding roots. Cycads in containers require watering every other day during summer, particularly during hot and windy weather, and must never be allowed to dry out completely. It is important that the growing medium be kept moist, but the excess water must be allowed to drain away to prevent rotting.
Propagation is by offsets and suckers. Encephalartos woodii does not go completely dormant, but growth does slow down during winter. Suckers are best removed in early spring, with a clean sharp spade or a knife. They should be larger than 100 mm in diameter; the larger the sucker the better its chance of survival away from its parent. Treat all cut surfaces, on the parent and the sucker, with flowers of sulphur to prevent fungal infection. Store the sucker in a cool dry place for about three weeks to allow the wound to seal. Before planting, dust the wound with a rooting hormone to stimulate the development of roots. Keep moist and in light shade until it produces new leaves, whereafter a weekly feed with a balanced liquid fertiliser during summer is recommended.
There being no female plant, seed is out of the question, but there are a few projects underway to remedy the situation. There is still the hope that a female plant is in the Ngoye forest somewhere and expeditions in that area always keep a look out for one.
The most promising project is the crossing of Encephalartos woodii with its closest relative Encephalartos natalensis, and crossing the offspring with Encephalartos woodii again with the result that each successive generation is more and more Encephalartos woodii.
There is also the remote possibility that a spontaneous sex change will occur in one of the male plants. Sex reversal has been observed in a few cases involving other species and once the process is more fully understood, it could be induced in an Encephalartos woodii plant.
Available E. woodii at Africa Cycads: