Encephalartos lanatus – Stapf and Burtt Davy (1926)

xxx Cycad (Eng), xxx Broodboom (Afr)

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Description


Encephalartos lanatus is a medium-sized plant with stems up to 1.5m tall. In old specimens the reclining stems can be up to 2m long. Stem diameter is typically 25cm to 30cm. The stem is covered in numerous, small leaf base scars, indicating the slow growth of this species. Mature plants generally have a single stem but branching can occur at the base. This species also produces suckers from the base.

The young leaves are densely hairy and have a silvery appearance. Mature leaves are 0.5m to 1m long and blue-green, sometimes slightly twisted in profile and strongly recurved at the apex. The petiole is 6cm to 10cm long and yellowish. The leaf base is covered with grey or white wool.

The pinnae have a silvery bloom when young and then mature to a green to blue-green colour, depending on conditions. Mature pinnae are linear, 10cm to 14cm long and 6mm to 8mm wide. They are crowded, regularly spaced and form a tight V on the rachis. The lower pinnae are reduced, but not spine-like. No teeth are present on the margins but each pinna terminates in a single, sharp spine. The abaxial surface of the pinnae has 10 to 14 parallel, clearly visible veins.

Pollen and seed cones are both covered with a persistent hairy layer, giving it a creamy-grey appearance. One to four cones are usually produced per stem. Males cones are 25-30cm x 5-6cm and cylindrical. Female cones are barrel shaped, 25-35cm long and 12-15cm in diameter. The scale faces protrude only slightly and the cones are carried on a peduncle 2cm to 3cm long. Seeds are 3cm by 2,5cm and covered with a yellow sacotesta.

Female cones

Male cones

Leaf detail

Distribution & Habitat


Encephalartos lanatus only occurs in a very limited number of sheltered, rocky valleys in the catchment area of the Wilge, Olifants and Little Olifants Rivers. The largest stands are found in the Botshabelo Mission Reserve and nearby farms. The plants grow in deep, sandy, fertile soils and rocks are sandstone of the Waterberg super group. Altitude is about 1500m above sea level. The area receives summer rains and averages 660mm to 770mm per annum. Summer temperatures are high, upto 40° Celsius, but in winter severe frosts occur often and temperatures can be as low as minus 10° Celsius. The general vegetation is described as sparsely wooded sourveld, with veld fires commonly occurring in winter. The fires may indeed be necessary for stimulating new leaf growth and coning in these cycads. Records indicate that this species has been collected in the Lowveld at Sabie, Pilgrim’s Rest, Nelspruit and Kaapsehoop, but this is undoubtedly incorrect. This is probably due to the early confusion between E. laevifolius, E. humilis and E. lanatus.
Cultivation & Propagation


E. lanatus is regarded as difficult in cultivation. Mature plants are rarely transplanted successfully and is slow to re-establish. The species grows easily from seed but growth is very slow. Plants are suited to cool subtropical and temperate areas and is frost hardy. Although new leaves are sensitive to wind and severe heat, plants should be grown in full sun. As usual for any cycad, they prefer well drained soils. Propagation is mostly by seed.

 

Notes


E. lanatus was first identified by one O.C. Weeber as E. fridericki-guilielmi after collecting a specimen in April 1911. It is still filed at Kew Herbarium as the type specimen for E. lanatus. Further collections were made by Dr Pole Evans (1915) and Dr Marloth (1923) but it was Joseph Burtt Davy who made the first thorough study of the Transvaal cycads. Together at Kew in 1926, he and Dr O Stapf wrote “A Manual of the Flowering Plants and Ferns of Transvaal, with Swaziland” and described and named E. lanatus, E. laevifolius, E. paucidentatus and E. transvenosus. In 1933 however, Hutchison and Rattray lumped E. laevifolius and E. lanatus together again. It was only in 1945, in his revision of the genus, that Henderson separated these two species based on differences in cone and leaf morphology. Dr Inez Verdoorn reinforced this decision with her work and it ultimately led to the description of E. humilis in 1951.

As is the case with all Encephalartos species, the seed kernels of this species are toxic. It has been shown that the kernels contain 0,1% Macrozamin and are a powerful liver toxin and carcinogen, if fed to rats. Baboons are fond of the fleshy sarcotesta and occasionally raid cones to get to these. The species is classified as vulnerable but, fortunately, large stands are in reserves and are well protected.