Biology:Cyathea dregei

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Cyathea dregei
Cyathea dregei00.jpg
Common Tree Fern growing on a river bank near Magaliesberg, South Africa
Scientific classification
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C. dregei
Binomial name
Cyathea dregei
Kunze, 1836
Synonyms
  • Alsophila dregei (Kunze) Tryon, 1970
  • Cyathea burkei W. J. Hooker, 1844
  • Cyathea angolensis Welwitsch ex W. J. Hooker, 1865

Cyathea dregei (common tree fern) is a widespread species of tree fern in southern Africa.

Within South Africa , it co-occurs with the indigenous forest tree fern (C. capensis) and the invasive C. cooperi from Australia . Further north, outside of South Africa, it coexists with an additional two tree fern species, C. manniana and C. thomsonii.

Common names

This species is locally known as the common South African tree fern or grassland tree fern (in contrast to its relative, the forest tree fern). It is commonly known as the gewone boomvaring in Afrikaans.

The specific epithet dregei commemorates Johann Franz Drège (1794-1881), a Germany plant collector and explorer who worked extensively in South Africa and who is referred to as Drège when citing botanical names.

Description

Key characteristics

The smallest leaflets of Cyathea dregei have distinctively smooth (entire) margins

Cyathea dregei has an erect, stout trunk is up to 5 metres (16 ft) tall and 20–45 cm in diameter. It is a variable species, usually having a thick trunk and dense crown. It is occasionally branched. Fronds are tripinnate (rarely bipinnate) and may reach 3 m in length. They are characteristically large and arching, with the lowest pinnae usually reduced. The upper surface of fronds is glabrate, while the lower surface may be tomentose. The rachis and stipe are brown in colouration and have a rough surface. The stipe is covered in brown scales. Up to twelve sori occur per group per pinnule.

Comparison to other Tree ferns

It can be distinguished from the forest tree fern (C. capensis) - the only other indigenous tree fern within South Africa - by its thick trunk, and by its smallest (third level) leaflets. The leaflets of C. dregei have smooth (entire) margins, while those of C. capensis are serrated. Each leaflet of C. dregei has multiple seedcases on its underside, while a leaflet of C. capensis has only one per leaflet. The fronds of C. capensis come off lower, and it usually has a several small, residual leaf remnants, which sprout in tufts among its fronds at the top of its stem.[1][2][3][4]

The only other indigenous tree ferns of the southern African region, Cyathea manniana and C. thomsonii, are both native to Zimbabwe. They can be distinguished from C. dregei by stem, stalk and frond appearance. C. manniana has sharp spikes on a slender trunk and frond stems. C. thomsonii has light-coloured, twisted hairs under its leaflets.[5]

The invasive C. cooperi can be distinguished from C. dregei by the hairy white and brown scales on the new unfurling leaf stipes and sometimes by faint serrations on the leaflets.

Distribution and habitat

It is native to Swaziland, Lesotho, Zimbabwe, Mozambique, Madagascar and South Africa from the Western Cape province to KwaZulu-Natal and Mpumalanga.

Cyathea dregei grows on stream banks, in forest margins and in grasslands. It often grows in the open, in full, direct sunlight, provided there is sufficient moisture. Plants are most common at an altitude of 900–1,800 metres (3,000–5,900 ft). In the wild, it is known to be fire resistant.

Cultivation

Cyathea dregei is relatively common in cultivation as an ornamental plant, especially in South Africa and Australia . Plants should be sheltered and grown in rich humus, with a constant supply of moisture. This species can survive light frosts with little damage.

Gallery

References

  1. https://www.operationwildflower.org.za/index.php/albums/ferns/cyathea-dregei-il-2-1892
  2. Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. p.86.
  3. Ferns of Africa - Cyathea dregei
  4. Thomas, V. (2002) Sappi Tree Spotting: Highveld and the Drakensberg: Tree & Shrub Identification Made Easy Jacana Media, p.52.
  5. https://www.operationwildflower.org.za/index.php/albums/ferns/cyathea-dregei-il-4-5488

External links

Wikidata ☰ Q5197558 entry