Encephalartos barteri

Observations on the West African Cycad in Ghana

By J. B. Hall and J. Jeník

With 5 photographs by the authors

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ENCEPHALARTOS barteri (West African Cycad) has attracted interest as the only widespread gymnosperm in West Africa ; (see article in Nigerian Field XXI, (i), 36-41 1956). In Ghana it occurs sporadically on rocky hillsides in the southern part of the guinea savanna. It is particularly abundant on the western slopes of the Volta Gorge where it grows in association with the grasses Loudetia simplex and Elymandra androphila and with the tree Lophira lanceolata. This formerly remote area is now well-known as the setting of the great Volta Dam at Akosombo. The crowds of visitors cannot help but see the cycads growing wild on the hillsides among the short scattered trees—or replanted in the garden of the hotel.

The fear that the construction of the dam might cause the extermination of Encephalartos led to a suggestion (which was never followed up) that as many plants as possible should be salvaged and replanted elsewhere in Ghana. But although many thousands of plants must have been killed by the excavations or drowned beneath the rising waters of the lake, great numbers remain in the grasslands at higher levels from the dam northwards as far as the Afram confluence.

The West African Cycad appears to be very well adapted to life in rocky, uncultivated savanna both in its structure and in its phenology. The stem is seldom more than a foot high, and most of its length is normally hidden below the soil surface, being pulled down by strongly contractile roots. The width of the stem is almost equal to its length, but there is very little wood. The outer third of its thickness consists of a fireproof armour of fleshy, tightly-overlapping persistent leaf-bases, whose woolly surface probably serves to reduce loss of water by evaporation, and also serves as insulation against fire. The centre of the stem is filled by a broad, soft pith which stores water and abundant starch. There is no record of Encephalartos barteri being eaten regularly, but the piece of pith which we chewed had a pleasant, nutty flavour even when raw. Other species of Encephalartos in South Africa are known to be edible, and the related Cycas is a source of sago.

The stem is as soft and fleshy as a yam tuber, and just as easy to cut. It is adapted to defeating the fires and droughts of the savanna dry season in the same way as the corm of Gladiolus or the bulb of Urginea. In fact the shape and fleshy leaf-bases are strongly reminiscent of the latter, but the leaf-bases of Encephalartos never shrivel.

On casual inspection the plants appear to be solitary and unbranched. But when we dug out a group of three, all of which were bearing female cones, we found them to be the branches of a single stock. A fourth, younger branch was just starting growth. It may well be the case that branching is frequent, and important in natural propagation. Young seedlings are certainly very scarce.

In the course of cutting a vertical section through an old stem we were surprised by the discovery of a chamber near the base of the pith from the ceiling of which roots were growing, quite isolated from the soil and from the atmosphere. The appearance was that of a miniature cave with stalactites. The floor had rotted from older cavities which we later found, and the adventitious roots had grown through the decaying tissues and into the soil. It appears that internal supplementary root formation may be a characteristic feature of Encephalartos barteri. The origin of adventitious roots from the pith is certainly most unusual and possibly unique, and merits further study.

The leaves wither and fall during the dry season, often as a result of fire. The cones develop at this time, growing laterally from leaf axils. It is unlikely that every plant produces cones each year. We found many more male than female cones which suggests that the male plants "flower" more frequently than the female.

The new leaves unfold from the terminal bud almost simultaneously and at great speed. The annual cycle—death of old leaves, growth of cones and flushing of new leaves—is similar to that of many West African savanna trees. A specimen which we observed closely in a garden at Cape Coast produced a single flush of leaves every year, and it is probable that this behaviour is also exhibited by wild plants. The age of a stem may therefore be estimated from the total number of leaf bases divided by the average number of leaves produced each year. At Akosombo we found the number of leaves in a flush to vary from 10 to 20 with a mean of about 12. A stem 12" long by 10" wide carried about 1400 leaf-bases and must therefore have been roughly a century old. Even allowing for considerable errors in the estimate, the rate of growth is thus extraordinarily slow.

We may well suspect this sluggishness of growth to be responsible for the restricted distribution of the species in Ghana. It is very successful in those places where it does occur, but it is sure to be left far behind in any situation where migration or re-establishment is required. It is known that there have been periods during the last million years when the West African climate has been moister than at present and forest must have covered much of what is now savanna. Perhaps Encephalartos barteri survived in a few places where the shallow, rocky soil prevented the growth of dense forest, but has been unable subsequently to recolonize wide areas of savanna.

See more contemporary photos of ENCEPHALARTOS barteri in the wild here >>>

Photographs Jan Jeník, December 4, 1966
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1. Encephalartos barteri with straight leaves, Ghana
2. The short trunk of a cycad about 100 years old. The age can be estimated by the number of leaf-bases. The botanists destroyed the rare plant only because it grew on the locality to be flooded by the new Volta Dam. Akosombo, Ghana
3. Male cone of Encephalartos barteri, grows after the savanna fire. Akosombo, Ghana
4. Rotten cavity in cycad trunk with interior roots
5. Encephalartos barteri, Akosombo, Ghana

Text first published:

Hall, J. B. and J. Jenik. 1967. Observations on the West African cycad in Ghana. The Nigerian Field 32: 75-81.

We would like to thank prof. Jan Jeník for providing us the text as well as the new scans of his original photographs.