E. aplanatus lacks aerial stems and has
a mostly subterranean habit. Plants are solitary with an exposed
apex. Branching or suckering does not occurs as is the case with
The plant has few leaves, 2-6 normally, with
occasionally 8 per plant. Young leaves are erect and arching but
becomes almost horizontal with age. Young leaves are covered in
fine hair but this is lost as the leaves get older. Leaves can
grow to 3.5m long with a petiole of 200mm. The petiole and lower
rachis is covered in a whitish indumentum.
The pinnae are directed towards the apex and
opposing leaflets are inserted at 180 degrees to each other. The
lower pinnae are progressively reduced to prickles. Median
pinnae are narrowly ovate, tapers to an acute but not pungent
tip with both margins sparsely dentate, very rarely entire.
Median pinnae are up to 300mm long, 40mm wide and dark glossy
green in colour.
Pollen cones number up to 3 per plant. They
are up to 650mm long, 80mm to 100mm in diameter and the peduncle
can be up to 220mm long. The male strobili emerge green but turn
a pale yellow when mature. The exposed part of microsporophylls
are flat, smooth and hairless. A female plant bears one or two
cones. They can be up to 400mm long and 120mm in diameter.
Peduncles are stout and up to 60mm long. The exposed faces of
megasporophylls are flat, smooth and also hairless, like the
microsporophylls. The facets are indistinct with sharp abaxial
ridges. The cones appear in January, mid summer, pollen is shed
in mid autumn and the female cones disintegrate in early to mid
Spring. Seeds are ellipsoid, about 25mm long and 13mm to 15mm in
diameter. The sarcotesta is bright red.
Distribution & Habitat
The species is endemic to, and occurs only in a
small area in the north eastern part of Swaziland. It occurs in the shade of
deciduous, fairly dry ravine forest. It is not known to occur with
E. villosus or
E. umbeluziensis. On a
field expedition by the author of the taxon, only one colony was found and
plants were scattered and not very healthy. Searching known localities where
the species occurred in the 1940's also proved to be fruitless. It is possible
that E. aplanatus was never abundant in the wild and to compound matters,
the species has been collected to near extinction.
Cultivation & Propagation
E. aplanatus can be treated much the same as
E. villosus given that the two species are closely related and have a
similar habitat. They like shade and well drained soils. Propagation is by seed.
Unlike E. villosus, E. aplanatus does not sucker to form clumps.
E. aplanatus was figured under E. villosus
by Dyer (1947) until it was described as a distinct species by Vorster. The two
species have nearly identical cones, the same acaulescent habit and small number
of leaves, 6-10 only. It is differentiated solely on vegetative characteristics
instead of differences in the reproductive structures. The leaves are longer,
3,5m as opposed to 2,5m in E. villosus, often shortly petiolate instead
of sessile and pinnae are larger, more dentate and the margins are twisted out
of plane or undulate.
Recent research found two related but distinct
species of Porthetes beetles present in both E. aplanatus and
E. villosus cones. These species are restricted to their specific host cycad
species and may provide additional support for the recognition of E.
aplanatus. Since the closest occurrence of E. villosus is 100km away,
E. aplanatus is not considered to be a hybrid involving that species. .
Full Sun to Semi-shade
Habitat photo 1
References & Acknowledgements
- Vorster, P. Focus on Encephalartos aplanatus. Encephalartos. 46
- Vorster, P. 1996. Encephalartos aplanatus (Zamiaceae): A new species
from Swaziland. South African Journal of Botany 62: 57-60