General Info

Tree up to 2m high.  Trunk: stern, sturdy.  Pinnately compound silver blue to green Leaves up to 1,5m.  Solitary dioecious Cones are greenish.  Barrel-shaped female cones up to 50 x 25cm.  The red Seeds are up to 5 x 2cm.

Description

Encephalartos lehmannii.

RSA Tree No. 8.1.

Common names: Karoo Cycad, Bread Palm, Bushman’s River Cycad.

Family:  Zamiaceae. This is a family of perennial cycads with 8 genera and about 200 species.  They are only superficially palm or fern like.  The cycad tap Root is soon replaced by lateral roots, which become woody.  Cycads have coralloid roots that contain symbiotic cyanobacteria (blue-green algae) that fix atmospheric nitrogen in association with root tissue and produce important amino acids for the plant.  Stems are cylindrical and southern African species do not have persistent leaf bases.  All are evergreen with pinnately compound Leaves.  The Leaflets have parallel (or nearly so) veins.  

Name derivation: Encephalartos – within-head-bread: referring to the starchy bread that can be made from the pith of the inner trunk.  lehmannii – named after Johann Georg Christian Lehmann (Prof) a German botanist who described several species of Cycad in 1834.  He created the Genus Encephalartos.

The genus Encephalartos includes some of the most primitive living Gymnosperms.  Unlike other members of the family Zamiaceae, species in the genus Encephalartos have leaflets that lack a central Midrib (vein).  Diamond shaped leaf scars remain on the trunk.  The hard prickly leaflets do not bend easily.  The sunken leaf veins are parallel or almost so.  Stomata (structure utilising 2 guard cells which, unlike lenticels, can control the gaseous exchange between the plant and the surrounding atmosphere) are present on the lower surface and may occur above.  All species are dioecious with male and female Cones on separate plants.  These cones develop in the centre of the leaf whorls.  At maturity, the Seeds are released when the Female cones disintegrate.  All species produce poisonous glycosides (cycasins).  The African plants in the genus Encephalartos include about 66 species and there are about 30 species are in southern Africa.

Conservation Status: Near Threatened. Assessment: 2009.10.31.  Plants are grazed by goats and their illegal harvesting are factors.

Tree

The trunk on this Tree often reclines and is up to 2m long.  This short and sturdy trunk has a diameter of up to 45cm.  Persistent leaf bases initially cover the trunk.  The plant is often multi-stemmed.

Leaves

Cycads are unique Gymnosperms with pinnately compound Leaves (leaflets arranged along either side of the leaf rachis, the central stalk, like a feather).  Young leaves are distinctly silver-blue with parallel veins.  Mature leaves become green and each leaf is up to 1,4m long.  The ends of the leaves may be curved backwards.  A small yellow collar is present where the Petiole (leaf stalk) joins the stem.  The petiole is up to 25cm long.  Petiolules (leaflet stalks) are absent.  The Leaflets do not overlap and are held horizontally.  A cross section of the rachis (main axis bearing flowers or leaflets) shows the leaflets are in a V-shape above the rachis.  At the base of the rachis, the leaflets may be reduced to spines.  The Margin is either entire (with a continuous margin, not in any way indented) or it may have small spines – only on the lower margins.

Cones

Trees are Dioecious (having male and female cones on separate plants).  Cones are single and both male and female cones do not occur every year.  Cone production is somewhat rain dependant.  Young cones have fine, dark hairs that causes them to look blackish.  These hairs are lost at maturity.  Male cones are up to 35 x 10cm, become bluish-green and are carried on a short stem and their green colour is revealed once the hairs disappear.  Pollen is located, in sacs, below each of the cone-scales.  The barrel-shaped Female cones are larger and up to 50 x 25cm.  Like the male cones, the green colour becomes apparent once the cones mature.  Two red Seeds are produced on the upper side of each female cone scale.  Each Seed is about 5 x 2cm.

Cycads are unique Gymnosperms with pinnately compound Leaves (leaflets arranged along either side of the leaf rachis, the central stalk, like a feather).  Young leaves are distinctly silver-blue with parallel veins.  Mature leaves become green and each leaf is up to 1,4m long.  The ends of the leaves may be curved backwards.  A small yellow collar is present where the Petiole (leaf stalk) joins the stem.  The petiole is up to 25cm long.  Petiolules (leaflet stalks) are absent.  The Leaflets do not overlap.  A cross section of the rachis (axis bearing, in this case, leaflets) shows the leaflets are in a V-shape above the rachis.  At the base of the rachis the leaflets may be reduced to spines.  The Margin is either entire (with a continuous margin, not in any way indented) or it may have small spines – only on the lower margins.

Distribution & Ecology

This cycads are Endemic (Endemism is the ecological state of a species being unique to a defined geographic location) in the Eastern Cape.  Trees are more or less isolated to non-coastal sandstone and outcrops and in dry areas where they seldom experience fires.  This results in their occurrence further west than most cycads.  These trees are frost resistant and exceptionally drought resistant.  They grow in areas with less than 360mm of rain per year.

Ethnobotany

The plants are best grown in full sun in a well drained area and should not be given excessive water.  They will grow from seeds or suckers.

References

http://biodiversityadvisor.sanbi.org/wp-content/uploads/sanbi-identify-it/plants/encephalartos.htm

http://www.theplantlist.org/browse/G/Zamiaceae/

https://www.diffen.com/difference/Angiosperms_vs_Gymnosperms

http://www.botanicwonders.com/Feature-Encephalartos-lehmannii.htm

Walter Sisulu Bot Gardens

http://www.wild-about-you.com/AfricaCycads.htm