Encephalartos

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Encephalartos
Encephalartos lebomboensis
Scientific classification
Kingdom: Plantae
Division: Cycadophyta
Class: Cycadopsida
Order: Cycadales
Family: Zamiaceae
Genus: Encephalartos
Lehm.
Species

See text.

Geographical distribution of genus Encephalartos

Encephalartos is a genus of cycad native to Africa. Several species of Encephalartos are commonly referred to as bread palms, bread tree or Kaffir bread since a bread-like starchy food can be prepared from the centre of the stem. The genus name is derived from the Greek words en (within), kephali (head), and artos (bread), referring to the use of the pith to make food. They are, in evolutionary terms, some of the most primitive living gymnosperms.

All the species of Encephalartos are endangered. The whole genus is listed under CITES Appendix I / EU Annex A, and CITES prohibits international trade in specimens of these species except when the purpose of the import is not commercial, for instance for scientific research.

Description[edit]

Several of the species possess stout trunks. In E. cycadifolius, the main trunks are up to 10 feet (3.0 m) high, and several of them may be united at a base where a former main trunk once grew. The persistent, pinnate leaves are arranged in a terminal spreading crown, or ascending. The rigid leaflets are variously spiny or incised along their margins.

Cones[edit]

Male cones are elongated, and three or four may appear at a time. Female cones are borne singly, or up to three at a time, and may weigh up to 60 pounds (27 kg). In some species, male cones with ripe pollen emit a nauseating odour. When the pollen has been shed and the males cones decay, a strong odour of acetic acid has also been noted.[1]

Roots[edit]

Colonies of the cyanobacterium Nostoc punctiforme occur in apparent symbiosis inside the root tissue,[1] while the rootlets produce root tubercles at ground level which harbour a mycorrhizal fungus of uncertain function,[1] which is however suspected to facilitate the capturing of nitrogen from the air.[2]

Food value[edit]

In several species the pith of the trunk contains a copious amount of high quality starch below the crown. This was formerly cut out by native people as food. Thunberg recorded around 1772 that the Hottentots removed the stem's pith at the crown and buried it wrapped in animal skin[2] for about two months, after which they recovered it for kneading into bread,[1] whence the vernacular name "broodboom" (i.e. bread tree). The burial of the pith apparently facilitated its fermentation and softening,[1] and the dough was lightly roasted over a coal fire.[3] In 1779 Paterson likewise found that the pith of a "large palm" near King William's Town was utilised by the Africans and Hottentots as bread. The pith was removed and left till sourish, before it was kneaded into bread.[1][4]

Their large seeds consist of an often poisonous kernel covered by an edible fleshy layer.[2] Female cones are consequently destroyed by baboons, as they relish the pith around the seeds.[1] Monkeys, rodents and birds also feed on the seeds, but due to their unpredictable toxic qualities they are not recommended for human consumption.[2]

Taxonomy[edit]

The genus was named by German botanist Johann Georg Christian Lehmann in 1834. All cycads except Cycas had been regarded as members of the genus Zamia until then, and some botanists continued to follow this line for many years after Lehmann had separated Encephalartos as a separate genus. His concept was originally much broader than the one accepted today, including also the Australian plants we now know as Macrozamia and Lepidozamia.[5]

Species[edit]

Reproductive cone of Encephalartos sclavoi.

See also[edit]

References[edit]

  1. ^ a b c d e f g Smith, Christo Albertyn (1966). Common Names of South African Plants. Botanical Survey Memoir 35. Pretoria: The Government Printer. pp. 179, 264. 
  2. ^ a b c d Palgrave, K.C. (1984). Trees of Southern Africa. Cape Town: Struik. p. 43. ISBN 0-86977-081-0. 
  3. ^ Van Bart, Martiens (16 May 1987). "Kirstenbosch kweek nou ook broodbome vir die publiek". Die Burger. Retrieved 21 January 2013. 
  4. ^ Paterson, William (1789), A Narrative of four Journeys into the Country of the Hottentots and Caffraria, in 1777-79 
  5. ^ Alice Notten (May 2002). "Encephalartos woodii Sander". Kirstenbosch National Botanical Garden and South African National Biodiversity Institute. Retrieved 2006-11-16. 

External links[edit]